Shape Memory Alloy (SMA) Fluid Fitting System - Aerofit LLC

3000 PSI CRYOFLARE ASSEMBLY (FLARED)

921883: CRYOFLARE SLEEVE, INSTALLATION PACKAGE AND NUT

NUT SLEEVE BLUE TRANSLUCENT F
CAP PACKAGE
C TUBE
T THREAD B HEX
A

HINGE DETAIL
VARIES WITH
SIZE

SECTION A-A A (3D BEND RAD)
CRYOFLARE ASSEMBLY “AS INSTALLED” MINIMUM STRAIGHT LENGTH OF TUBE

“AS SHIPPED” CONDITION WITH 3D BEND

PART NUMBER TUBE SIZE B C F THREAD PER AS8879
MIN
.4375-20 UNJF
921883( )04 .250 .562 1.238 1.23 .5625-18 UNJF
921883( )06 .375 .688 1.483 1.27 .7500-16 UNJF
921883( )08 .500 .875 1.718 1.31 .8750-14 UNJF
921883( )10 .625 1.000 1.941 1.51 1.0625-12 UNJF
921883( )12 .725 1.250 2.207 1.63

Part Number Example: 921883 W 08

BASIC PART NUMBER ISNIZCERCEOMDEEN,TTSUBE SIZE IN .062
MATERIAL CODE LETTER

a. LETTER “J” AFTER BASIC PART NUMBER INDICATES ASSEMBLY WITH 304 CRES CORROSION RESISTANT
STEEL NUT

b. LETTER “W” AFTER BASIC PART NUMBER INDICATES ASSEMBLY WITH 7075-T73 ALUMINUM ALLOY
NUT

NOTES: SLEEVE
1. MATERIAL: TINEL HEAT RECOVERABLE, SHAPE MEMORY ALLOY
“J” 304 CRES PER QQ-S-763
NUT “W” 7075-T73 PER QQ-A-225/9
RED TRANSLUCENT POLYCARBONATE


CAP PACKAGE

2. FINISH: SLEEVE DRY FILM LUBRICANT ON TAIL

NUT “J” PASSIVATE PLUS DRY FILM LUBRICANT PER MIL-L-46010,

TYPE 1 ON INTERNAL SURFACES

“W” ANODIZE PER MIL-A-8625 TYPE II, CLASS 1 PLUS DRY FILM

LUBRICANT PER MIL-L-46010, TYPE 1 ON

INTERNAL SURFACES

CAP PACKAGE - NONE

51 www.aerofit.com

Installation CRYOLIVE AND CRYOFLARE PRODUCTS

I. Introduction

CryOlive and CryoFlare shape memory alloy sleeves and coupling nuts are components of a flareless fluid fitting
connection. The sleeves are installed on the ends of tubes and permit the tubes to be connected to tees, elbows,
unions, etc., with ends machined per military standards AS33514 and AS33515.
CryOlive and CryoFlare sleeves are manufactured from Tinel shape memory alloy. The ID of the sleeve is ma-
chined somewhat smaller than the OD of the tube it will be installed upon. After fabrication, the sleeve is cooled
to cryogenic temperatures, -320ºF, in liquid nitrogen (LN2). When cooled, the shape memory alloy undergoes
a transformation from a high strength, austenitic phase to a relatively low strength, martensitic phase. While
in the cooled, low strength phase, the sleeve is “expanded” to an inside diameter slightly larger than the OD of
the tube it is to be installed upon. When the sleeve is removed from LN2 and allowed to warm, the austenite to
martensite transformation is reversed, and the sleeve “recovers” to its pre expanded, or as machined, diameter
and its high strength state. This transformation and expansion process can be repeated if the sleeve has “recov-
ered” prior to installation.
To install the sleeve on a tube, the sleeve is removed from the LN2 and immediately slipped over the end of the
tube and allowed to warm up and recover. The tube OD, being larger than the ID that the sleeve wants to revert
to, constrains the sleeve’s recovery. During constrained recovery the alloy develops considerable force and ef-
fectively “self swages” the sleeve permanently onto the tube.
The sleeve and coupling nut come pre assembled in a disposable molded installation package (Figure 1). As-
semblies are shipped and stored in liquid nitrogen and are removed from LN2 just prior to installation.

Figure 1

CRYOLIVE CRYOFLARE
ASSEMBLY ASSEMBLY

CryOlive and CryoFlare assemblies should be removed from their storage containers and installed only by
personnel who have been properly trained in the handling of liquid nitrogen and installation of CryOlive and
CryoFlare sleeves. Please see Section D for safety and handling of liquid nitrogen.

52 www.aerofit.com

II. Installation Tools

CryOlive and CryoFlare sleeves are installed by using simple tools purchased direct or through our stocking
distributors. The function of each tool is described below.

1. TONGS: Instrument used to transfer and remove assemblies from insulated workbox. Product Descrip-
tion: AT911067-01.

2.WORK BOX: A small insulated box used to transport assemblies from the storage area (see Logistics sec-
tion) to the work area. Product Description: WB910825-01

3. GLOVES: Thin, well insulated gloves, which are used when handling assemblies that have been stored
in liquid nitrogen. They must NOT, under any circumstances, be immersed in liquid nitrogen. Product
Description: OE Glove Liner- (S-M-L)

4. Safety Glasses: Safety glasses with side shields should be used at all times.

III. INSPECTION OF SLEEVE I.D.

If there is reason to believe that the sleeve within the assembly has recovered (such as from a low liquid nitro-
gen level in the storage dewar), its inside diameter can be checked as follows:
1. Obtain a length of the appropriate size tubing approximately 6” long.
2. Cool the tube end in liquid nitrogen (work box) until the boiling stops.
3. Being careful to keep the assembly in liquid nitrogen, insert the cooled tube onto the assembly. The tube

should bottom out against the assembly end (CryOlive) or the stop (CryoFlare). This can be checked by
viewing the end of the tube through the inspection window of the package. If the tube cannot be inserted
into the assembly and through the sleeve, the assembly should be removed from stock. Return the sleeve for
reexpansion. A nominal fee is charged for this service.

IV. Installation Process

NOTE: CryOlive and CryoFlare assemblies should be installed only by properly trained personnel.
1. Obtain the proper CryOlive or CryoFlare assemblies from inventory. Refer to the application table for assem-

bly description.
2. Ensure that the tubes are round and free from burrs and meet dimensional specifications.

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3. Clean and dry end of tube, if necessary, by wiping with a clean rag or cloth.
4. Put on gloves. NOTE: Do not put gloved hand in liquid nitrogen.
5. Using tongs, remove the assembly from the liquid nitrogen and allow the excess liquid nitrogen to run off.
6. Grasp the assembly with gloved hand. Without delay, slip it over the tube end and push until the tube end

is firmly seated against end stop inside the plastic installation package. The tube must bottom out against the
assembly end (CryOlive)(Figure 4) or tube stop (CryoFlare).
7. The package is designed to provide the proper tube insertion. To do so the tube must be fully bottomed
against the inside end of the package. For CryOlive the tube end should be visible in the slot (inspection win-
dow) and should butt against the inside end of the package (Figure 2). For CryoFlare the tube must bottom
on the tube stop.You may leave plastic installation package on tube end to protect sleeve and act as a dust cover
until ready to mate with fitting.

Figure 2

8. To remove the plastic installation package, unscrew the nut and remove the plastic package.

Figure 3

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9. Tube protrusion and other installation related dimensions are found in the Specification Control Drawings.

V. TUBE APPLICATION SPECIFICATIONS

Torque the CryOlive or CryoFlare nut to the value listed in the following tables.

AsBsNaesumimcbSblyMePrA a rt Tu be Material SpecTiufibcea tion TSuizb ee TThuibceknWeaslls IncInh sLtbalsla tion Torque System Temperature
Nm Operating Range
Pressure
4 0.020 135-145 15.3-16.4 -65° F thru
6 0.028 215-245 24.3-27.7 3000 psi 275° F
8 0.035 470-510 53.1-57.6 3000 psi
921721 OR 304 1/8H CRES MIL-T-6845 10 0.042 610-680 68.9-76.8 3000 psi -65° F thru
921883 0.058 810-945 91.5-106.8 3000 psi 275° F
12 3000 psi
16 0.065 1,140-1,260 128.8-142.4 3000 psi -65° F thru
4 0.016 135-145 15.3-16.4 3000 psi 275° F
6 0.020 215-245 24.3-27.7 3000 psi
8 0.026 470-510 53.1-57.6 3000 psi -65° F thru
921721J OR 21-6-9 CRES AMS 5561 10 0.033 610-680 68.9-76.8 3000 psi 275° F
921883J 0.039 810-945 91.5-106.8 3000 psi
12 3000 psi -65° F thru
16 0.052 1,140-1,260 128.8-142.4 1500 psi 275° F
4 0.028 135-145 15.3-16.4 1500 psi
6 0.028 215-245 24.3-27.7 1500 psi -65° F thru
8 0.035 470-510 53.1-57.6 1500 psi 275° F
10 0.035 610-680 68.9-76.8 1500 psi
921721W OR 6061-T6 MIL-T-7081 12 0.035 810-945 91.5-106.8 1500 psi
921883W ALUMINUM 0.065 1,140-1,260 128.8-142.4 500 psi
16 500 psi
20 0.035 1,520-1,680 171.7-189.8 3000 psi
24 0.035 1,900-2,100 214.7-237.3 3000 psi
4 0.016 135-145 15.3-16.4 3000 psi
6 0.019 215-245 24.3-27.7 3000 psi
8 0.026 470-510 53.1-57.6 3000 psi
921721T 3AL-2.5V CWSR AMS 4944 10 0.032 610-680 68.9-76.8 3000 psi
TITANIUM 0.039 810-945 91.5-106.8 4000 psi
12 4000 psi
16 0.051 1,140-1,260 128.8-142.4 4000 psi
4 0.020 135-145 15.3-16.4 4000 psi
6 0.019 215-245 24.3-27.7 4000 psi
8 0.019 470-510 53.1-57.6 4000 psi
921504 3AL-2.5V CWSR AMS 4944 10 0.032 610-680 68.9-76.8 4000 psi
TITANIUM 0.039 810-945 91.5-106.8 2000 psi
12 2000 psi
14 0.045 985-1,090 111.3-123.3 2000 psi
16 0.051 1,140-1,260 128.8-142.4 2000 psi
6 0.020 215-245 24.3-27.7 2000 psi
8 0.020 470-510 53.1-57.6 2000 psi
10 0.023 610-680 68.9-76.8 2000 psi
12 0.027 810-945 91.5-106.8 150 psi
921504 3AL-2.5V CWSR AMS 4944 14 0.032 985-1,090 111.3-123.3 2000 psi
TITANIUM 0.036 1,140-1,260 128.8-142.4
16
20 0.045 1,520-1,680 171.7-189.8
24 0.032 1,900-2,100 214.7-237.3
24 0.054 1,900-2,100 214.7-237.3

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Logistics

(Liquid Nitrogen Handling And Storage)

LOGISTICS – SMA FLUID FITTING SYSTEM

Liquid Nitrogen Storage & Handling
1. Introduction

Shape Memory Alloy (SMA) fittings are used to permanently join sections of tubing and are stored in liquid
nitrogen until just before installation. When received, the fittings have an inside diameter which is larger
than the outside diameter of the tubes they will be installed onto. If removed from the liquid nitrogen and
allowed to warm, the couplings will shrink so that the inside diameter will be smaller than the tube outside
diameter. If the coupling is slipped over the tube/fitting ends before it warms, the fittings will shrink and
swage onto the tube or fitting.
2. Shipping and Storage Containers
CryoFit unions and separable fittings called CryOlive (flareless) and CryoFlare (flared) fittings are shipped and
stored in special insulated liquid nitrogen containers called dewars or are stored for longer periods of time
in freezers. Dewars and freezers are available from Aerofit, Inc. or their distributors. The size of the dewar or
freezer is dependent on the quantities of fittings to be shipped and/or stored.
A dewar functions like a thermos bottle by controlling the boil off or evaporation of liquid nitrogen (LN2)
and thus maintaining the inside temperature of the vessel at a relatively constant -320° F. The smaller the neck
of the dewar, the slower the evaporation process and the longer a constant temperature will be maintained.
It is important to note that replacing the neckcore into the dewar after loading/removing SMA products is
vital in helping to control LN2 evaporation. Required servicing intervals are delineated in the manufacturer’s
literature for each dewar type/design.
If frost is noted on the outside of the dewar at any time, transfer the SMA parts to another container and re-
move the dewar from use. Frost indicates that the vacuum has been broken and it will no longer maintain
LN2 per its design and usage specification.
If the dewar shows no sign of frost on the exterior, it only needs regular servicing of LN2 to maintain the
SMA parts in their expanded state. Shape Memory Alloy parts are to be submerged in liquid nitrogen until
removed for installation.
If the dewar has a large mouth and neck, it is possible to see the LN2 and determine its depth. If the dewar
has a small mouth and neck, the quantity/depth of the liquid nitrogen can be determined by observing the
condensation on the outside of the parts canisters when removed from the dewar.
NOTE: if the neckcore of the dewar is removed and it is determined that only a minimal amount of liquid
nitrogen or vapor is left in the dewar, immediately replenish the liquid nitrogen. In most cases, the parts will
remain in their expanded state, but they should be checked before installation is begun.

Liquid Dewar

This unit is suitable as a shipping container and for short term storage. Liquid
nitrogen level must be checked every few days and topped off if necessary. Least
economical shipping container due to weight.

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Vapor Dewar OShOuuitpteeprrpPiiPnrnogrgtoeCctoCteivvoceertvSievhriep- Dewar

VTahpisour nDiet wisaerxcellent as a shipping container or for medium Dewar
term storage. This style Dewar has a liner which absorbs
tTlwlpsieiqhhaqirluirmiluspitrdsipedusmiwnnntinoatiigtrriliotlaniwrgsgroceeeegeonmi.exlgdancahTeniftnoald.hlrneiWcsindunotphshlidiantbetyoshniflteositabbwreDoiosuvtetshaphwwipepettavopoherariekanpthstgwoliaoiranoscnaneot.dwiarnoItaernnaleneiin.dtnkdheuesIirsscrnatewoncostorrdhhantiihfgcrsdoeheeirctdicsoomauhhnnbceiadpsepdmopisaituriibnrtbomthgessner
wareeigfhutl.l oWf hlieqnuibdonthittrhoegelinneSrMaAndpsatrotsracgaencbheamstobererdarfoerfuulpl otfo
laiqmuidonntihtrowgiethnoSuMt tAopppairntsg coafnf. be stored for up to a month

without topping off.

Freezer System

FTrheieszuenriSt iyssstuepmerior for long term storage. Features include temperature con-
taTdtlrirnoheqodgitusleeimraudnmnnondfiniitlniilittmsioranornsogignudnegptihnaetaoeurlfiratoiqoilrrnlumcfgaaolnensradaytlliosratatnyreoumgfmototff,eossregcymtlasoeftsoraesyerrmtdoaiomr,capfcepgrfeaoroeossd.gysvueftacFdoocterscspa.eitatomsursrtrepetidrdsooepivnsnretoctoiddlfuricuedpacdeatt,irotpteanriumodtapodenemnudrtcaaitdftt,iiueccartaeelutiqritcmoouonimidnntiaarnnnotigi-ldc

the quantity of stored products.

3. Packing for Shipment Freezer

Fo3r.shPipamckeinnt,gSMfoAr fSithtiinpgms aerentpackaged in canister tubes in the small dewars or half trays in the large dewars.
FoFrorshsihpippminegn,t,thSeMdAewfitatirngiss aatrteacphaecdkatogead sipneccaianlisptearlletutbdeessiignntehde tsompalrledveewntarist forrohmalfb-terianygs tiniptpheedlaorvgeer.deE-ach
cawnaisrste.rFoor hshalipf ptrinayg,isthteagdgeewdatroisidaetntatcifhyedpatrotsainspceacniaisltepralolert tdraeys.igned to prevent it from being tipped over.

Each canister or half tray is tagged to identify parts in canister or tray.

Hinged Lid

Locking tab

i6cnaotnerirsmnteaorlsre Canister Tube Half Tray

FPoluagm

Dawnoidtuhvbialnecsuwuulamaltlion
Bchooansledfigcaunreisdtetros

Small Dewar Large Dewar

4. Receiving Procedure

Tchh4ee.cskRheidepcmaeteirnveticneaginvdiPnsgrt.oorcTaehgdee uiRnreelleiqasueidNnoitter/oCgeenrtimficeaatnesotfhaCtoint fiosrumniltiykeolyn to be practical for SMA fittings to be
the outside of the container may be
rceocTmnhhteeoacviksneehdedirpsbmaymterrnueetscctaeebniivvediinnfsgogt.rowrsTaoahgrteedheRaindtetlluiehqnaeuosidqepuenNnaiotnertodteigttie/oenCstehmmreteaifuayicnsaebstreetdh‘obeafpot Caoitroktinemsdfoeu-rinnmnlti’.iktyeanlyodntotthhbeeeodpuortcasuicdmteiceaonlftftohpreaSscsMoendAtaofiinntteintrgomsQatoyA.bbeeThe

removed by receiving so that the quantities may be ‘booked-in’ and the document passed on to QA. The con-

tainers must be forwarded unopened to the user department.

528 wwww.waewro.faite.croomfit.com

When received by stores or the user department, the liquid nitrogen level in the dewar should be checked.
If the level has dropped, it should be replenished. On receipt, by stores or the user department, the liquid
nitrogen level in the dewar should be checked and topped off at regular intervals thereafter.

5. Transfer of Fittings

The transfer of fittings from the shipping dewar to the storage dewar should be made as quickly as possible.

Transfer from a Half Tray

Transfer from a half tray is accomplished by moving the half tray to a shallow insulated foam tray filled
with liquid nitrogen.
1) Fill the storage dewar with liquid nitrogen.
2) Fill the storage half tray or inventory control system drawer with liquid

nitrogen.
3) Fill the foam tray with approximately 3” of liquid nitrogen.
4) Remove the shipping half tray from the shipping dewar and place in the

foam tray.
5) Select the proper tools and cool.
6) Using the proper tool, transfer the fittings from the shipping half tray to

the storage container one at a time.
7) It is desirable to verify and record the quantity of fittings received at this

time.
8) After completing the transfer, return the storage half tray or drawer to the

storage dewar or freezer.

Transfer of couplings from dewar canister to work box

1) Fill the work box with approximately 3” of liquid nitrogen.
2) Remove the canister tube from the dewar and remove any wad-

ding (sometimes inserted to ensure couplings remain in canisters
during transit)
3) Position the canister over the work box and tip it so the couplings
slide into the work box.

Transfer of couplings from Work Box to the canister www.aerofit.com

To return couplings from work box (as for example after verifica-
tion)
1) Top up the work box with liquid nitrogen if necessary & stand

the canister in the work box.
2) Cool the tongs.
3) Pick up the couplings with the tongs and transfer them into the

canister
4) Ensure liquid nitrogen level is sufficient to cover the couplings at

all times.
5) Return the canister to the dewar (tip the canister slightly so that

it engages the slot in the base of the dewar).

59

6. Storage

SMA fittings can be stored in liquid nitrogen indefinitely.
The storage containers are unpressurized and are therefore refilled by simply pouring liquid nitrogen directly
into the container.

• Pouring should be done slowly, especially when pouring into empty vessels at ambient temperature
to minimize thermal shock to components

• Care should be exercised when adding liquid nitrogen from a pressurized source directly to a con-
tainer which contains SMA fittings. There is a small risk that a pressurized ‘stream’ from a hose in
the base of the container could push small size parts out of the canisters and into the main body of
the container.

7. SMA Fitting Recovery Check

If there is reason to believe that a coupling has been warmed (such as from a low liquid nitrogen level in the
dewar), its inside diameter can be checked as follows:

1) Obtain a length of the same size tubing as the coupling, ap-
proximately 6 inches long.

2) Cool the end of the tube in liquid nitrogen until boiling stops.
Point the upper end of the tube away from the face and body as
small diameter tube will create a ‘fountain’ effect as it cools.

Fountain Effect

3) Being careful to keep the coupling in the liquid nitro-
gen, insert the tube into the coupling.
4) The tube should easily slip through the entire bore of
the CryoFit fitting
5) If the tube cannot pass through the fitting, the fitting
should be removed from stock and returned to the sup-
plier for reexpansion.

8. SMA Fitting reexpansion

SMA fittings which have been allowed to warm prematurely may be returned to the supplier for reexpansion.
SMA fittings should be carefully packaged so as to prevent damage (especially to the coating on the extremi-
ties) before return. Before reexpansion the couplings are carefully examined for damage, restenciled with a
unique reexpansion batch number and issued with a new Certificate of Conformity. The cost of this process
is approximately 30% of the cost of a new SMA fitting, however transport and set up costs mean that it may
be uneconomic to reexpand batches of less than 100 couplings (or 50 on larger sizes).

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9. Liquid Nitrogen Safety

The following precautions are provided to assist the user of SMA fittings in developing adequate safety stan-
dards for use of liquid nitrogen. They are intended as guidelines only and should not be considered binding
recommendations. The safe handling of liquid nitrogen and cryogenically cooled components is the user’s
responsibility.

1) Liquid nitrogen will displace oxygen in confined spaces. Its volume expansion from liquid to gas at
standard conditions is 696 to 1. Evaporation of large amounts of liquid nitrogen in unventilated or
confined spaces may cause suffocation. Therefore, working areas should be provided with adequate
ventilation.

2) Liquid nitrogen at -320° F (-196°C) can cause frostbite or “burn” if it is in contact with the skin
for more than a few seconds. Brief contact with the liquid due to accidental splashing will not cause
harm. Care must be taken to avoid trapping spilled liquid nitrogen against the skin. Wear loose fitting
clothing. Pants should be long enough to cover the tops of the shoes.

3) Thermal Gloves recommended by Aerofit, Inc. are to be used when handling tooling and SMA fit-
tings which have been cooled by liquid nitrogen. Gloves should not be directly submerged in liquid
nitrogen.

4) Eye damage can result from splashed liquid nitrogen: suitable eye protection should be worn (Safety
Glasses or Goggles).

5) Do not come into contact with areas of tools, couplings or materials which have been cooled by liq-
uid nitrogen, as they can also cause frostbite.

6) Bulk transfer of liquid nitrogen should be performed only by trained personnel.
7) Small quantities of liquid nitrogen must be poured slowly to avoid splashing, thermal shock and rapid

build up of pressure.

Emergency Action if a liquid nitrogen spill occurs:

1) Remain clear of the spilled liquid. Allow it to evaporate as a result of shop ventilation.
2) Immediately remove any clothing or shoes which have been soaked with liquid nitrogen; flush skin

with lukewarm water and seek immediate medical attention if burned.
3) In case of eye contact, flush with water and get immediate medical attention.
4) In case of asphyxiation and loss of consciousness move person to ventilated area and seek immediate

medical attention.

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General Information

GENERAL INFORMATION

Warranty of Couplings and Fittings

Aerofit, Inc. warrants that CryoFit couplings, compatible fittings, CryOlive flareless, CryoFlare flared end fittings,
and tooling will be free from defects in design, material, and workmanship. Should any SMA fitting, coupling
or tool fail in service, it will be replaced by Aerofit, Inc. at no cost.

Warranty Terms and Conditions

• Proper storage, handling and installation are required, as shown in Aerofit, Inc. published document
• Couplings must be installed on qualified and certified tube material, OD, and wall thickness combinations,

or on Aerofit, Inc. supplied or approved CryoFit compatible fittings
• Failures attributable to designs, modifications, and repairs that are not consistent with accepted design prac-

tice are not covered under this warranty.
• This warranty is not assignable to third parties (except the US Government) without the prior written con-

sent of Aerofit, Inc.
• The cost of repairs is not covered under this warranty.

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GENERAL INFORMATION

AIRCRAFT MANUFACTURER APPROVALS

Manufacturer Cryofit CryOlive Light CryoFlare
(Partner Weight
Union
Companies in same
Parentheses) tube
Titanium CRES Aluminum Titanium CRES Aluminum materials CRES Aluminum
3AL-2.5V 21.6.9 6061-T6 3AL-2.5V 21.6.9 6061-T6 21.6.9 6061-T6
304-1/8H 5052-0 304-1/8H 5052-0 as 304-1/8H 5052-0
321 321 CryOlive 321

BOEING

727, 737, 747, 3PHS111 921721T- 921721J- 921721W-
757, 767, 777, 787

DC-9, DC-10, 4PHS 4PHS 921721T 921721J
MD-80, MD-11

X-36 Remotely 4PHS
Piloted Vehicle

C-17 (Northrop 4PHS111 921853
Grumman)

Canard Rotary Wing 4PHS

747 Airborne Laser 4PHS

LOCKHEED MARTIN 3PHS111 921883- 921883W
F16 (Block 60) 3PHS111 3PHS111 921883- 921883W

BOMBARDIER

deHQav2i0ll0an, dQ3D0a0sh 7,

deHavilland Dash 8 3PHS111 3PHS111

Canadair Challenger 3PHS111 3PHS111

Canadair Regional Jet 3PHS111

AIRBUS Refer TDD (Technical Design Directive)
A300,A310,A318, 921721T 921721J 921721W 921895

A319,A320,A321 A330, 3PHS111 3PHS111
A340,A350,A380

A380

DASSAULT

Falcon Jet 3PHS111 3PHS111 NTO Status

GULFSTREAM (Northrop Grumman)

GV 3PHS111 3PHS111 3PHS111 921721T 921895

GIV 3PHS111 3PHS111 3PHS111

MARSHALL AEROSPACE

L1011 3PHS111

64 www.aerofit.com

Manufacturer Cryofit CryOlive Light CryoFlare
(Partner Weight
Union
Companies in same
Parentheses) tube
Titanium CRES Aluminum Titanium CRES Aluminum materials CRES Aluminum
3AL-2.5V 21.6.9 6061-T6 3AL-2.5V 21.6.9 6061-T6 21.6.9 6061-T6
304-1/8H 5052-0 304-1/8H 5052-0 as 304-1/8H 5052-0
321 321 CryOlive 321

RAYTHEON

King Air 4PHS 4PHS
4PHS111 921721T-
Premier 1 4PHS111 921895
Hawker Horizon 4PHS111 4PHS111 921721T- 921895

(FHI) 5PHS111 921721T- 921721J- 921721W
BELL HELICOPTER 921721T

UH-1 921721T-

V-22 (Boeing)

B609 (Agusta)
CESSNA

Citation X Proto-type 4PHS111 4PHS111 921721T 921721W

Model 650 4PHS111 4PHS111 921721T 921721W
4PHS111 921721T 921721W
Model 750 4PHS111

SAAB

340 4PHS

2000 4PHS
NORDAM Thrust Reversers for:

Citation 550/560 921721T 921721J
Lear 45 921721T 921721J

Hawker Horizon

U.S. DEPT of DEFENSE

C-17 (Douglas) 4PHS111

F-14 3PHS
(Northrop Grumman)

T-1 3PHS1
(Lockheed Martin)

B-1B (Rockwell) 4PHS

V-22 (Bell/Boeing) 5PHS111
T-45 (BAE/Boeing) M4PHS111

767-AWACS (Boeing) 4PHS 4PHS
707 JSTARS 4PHS

(Lockheed Martin) 4PHS

C-5 (Lockheed Martin)

F-22 (Boeing) CP Ti 6.4
F16 and Inc-
onel 625
(Lockheed Martin)
3PHS111

65 www.aerofit.com

Manufacturer Cryofit CryOlive Light CryoFlare
(Partner Weight
Union
Companies in same
Parentheses) tube
Titanium CRES Aluminum Titanium CRES Aluminum materials CRES Aluminum
3AL-2.5V 21.6.9 6061-T6 3AL-2.5V 21.6.9 6061-T6 21.6.9 6061-T6
304-1/8H 5052-0 304-1/8H 5052-0 as 304-1/8H 5052-0
321 321 CryOlive 321

NON U.S. GOVERNMENT

Taiwan IDF 4PHS 4PHS
(Lockheed Martin)

Harrier GR5/GR7 4PHS111
/T10 (BAe)

Eurofighter M2PHS111
Ty-phoon(EADS, Bae, M4PHS111

Alenia)

The following table is intended to summarize the historical qualification and technical development of the cur-
rent CryoFit couplings series.

Product Year System Background OEM User
Series Qualified Operating Tubing Type Qualifications Qualifications
4PHS111 Pressure
1985
First fitting made from Tinel Alloy AHS, Northrop, Boeing
designed using Finite Element Analysis. Military, Vought,
4000 psi About 35% shorter and lighter than 4P0 McDonnell U.S Navy,
Ti-3Al-2.5V counterpart, but with longer recovery U.S Air Force,
time. Allowable installation gap is 0.120”. Douglas, Hughes Royal Air Force
Developed and qualified for the B-2 and Space & Com-
munications, GE (Harrier)
Northrop ATF.
Satellites

2PHS111 1985 2000 psi Ti-3Al-2.5V Made from Tinel Alloy AHS. Roughly Northrop, Boeing U.S Navy,
35% shorter and lighter than 4P0 counter- Military, Vought, U.S Air Force

part, but with longer recovery time. McDonnell
Allowable installation gap is 0.120”. Douglas, Hughes
Used in conjunction with 4PHS system.
Space & Com-
munications, GE

Satellites

M4PHS111 1986 4000 psi Ti-3Al-2.5V Made from Tinel Alloy AHS. Allowable BAe, U.S. Navy
M2PHS111 1986 3000 psi BS T72-T73 installation gap is 0.120” (3 mm). Metric McDonnell U.S. Navy
5PHS111 1987 coupling developed and qualified for the U.S. Navy
3PHS111 1995 1000 psi T-45 Goshawk and now selected for the Douglas
Air France,
5000 psi Eurofighter Typhoon. United Airlines

3000 psi Made from Tinel Alloy AHS. Allowable BAe,
3000 psi BS T72-T73 installation gap is 0.120” (3 mm). Metric McDonnell
3000 psi
1000 psi coupling developed for use in conjunction Douglas
with the M4PHS111 system.

Ti-3Al-2.5V Made from Tinel Alloy AHS. Allowable Northrop,
installation gap is 0.120”. Developed and McDonnell
qualified for the Bell/Boeing V-22 and the Douglas, Bell
Helicopter, Boeing
McDonnell Douglas A-12. Helicopter

Ti-3Al-2.5V Made from Tinel Alloy AHS. Allowable instal- Airbus Industrie,
lation gap is 0.300”. Originally qualified to
21-6-9 ISO 7169 for Airbus as a direct replacement Boeing,
deHavilland
for Rynglok and Permaswage. Designed to
304-1/8 be the single coupling for commercial air-

6061-T6 craft original installation and repair.

66 www.aerofit.com

GENERAL INFORMATION

CryoFit® Couplings for Space Vehicle Plumbing Systems

CryoFit couplings have been used in Space Vehicle applications dating back to the mid-1970s.They have been
qualified by Lockheed Missiles & Space Company (1974), General Electric Astro Space (1991) and Hughes
Space & Communications (1994). CryoFit couplings have also been evaluated for space vehicle applications
in the UK, Japan and Germany and by Boeing Defense & Space Group. All testing has been conducted at the
expense of the companies and test reports are considered proprietary.This fact sheet is intended to summarise
the conclusions of those reports and such details as are known about any ongoing testing.

Company Product Tests Results Space Vehicle
Series and Tube Types Propellant Performed Applications

Sizes

Lockheed 4P02111 304CRES N2H4 Tensile strength, All mechanical test results deemed Unknown (but see
Missiles & 1/4”, 1/2”, joined to: Burst, Gas Leak, acceptable. CryoFit couplings not entry under Primex
Space 3/4” Ti-3Al-2.5V, Vibration, affected by hydrazine and no trace Aerospace below)
Company 304CRES, Contamination, of titanium or nickel found in
2021Al Hydrazine hydrazine after test.
compatibility

General 4P02111 Ti-3Al-2.5V N2H4 Unknown All mechanical test results deemed Unknown
Electric 3/8” MON-3 but included acceptable. No untoward effects
Astro Space propellant were noted during the metallurgi-
compatibility cal evaluation of CryoFit sleeves
after propellant exposure.
Hughes 4PHS111 Ti-3Al-2.5V MON-3 Gas Leak; CryoFit couplings met all require- UHF/F2;
Space & 1/4”, 3/8” per MIL- ments of use with liquid propulsion Brasilsat;
Communica- Propellant systems with the propellants listed. GMS-5, MSAT E-1
P-26539; compatibility; Service with xenon gas qualified by PANAMSAT K-1
tions Monomethyl- Burst pres- similarity to helium. Recommend-
hydrazine sure; Impulse; ed as an alternative to welding or
per MIL- Thermal flareless tube coupling where high
P-27404; cycle; Flex; strength, high reliability and ease of
Hydrazine Metallograph- installation are important factors.
per MIL- ic analysis In 1999 Hughes reported an ag-
P-26536; gregate 800 problem-free years in
Helium per space for the CryoFit couplings on
MIL-P-27407 their spacecraft.

DASA Space 4PHS111 & Ti-3Al-2.5V Hydrazine Hydrazine All tests completed satisfactorily. Globalstar 2
(Daimler- 921721 compatibil- DASA noted (as had GE) that Xylan Teledesic
Benz (Cryolive) ity, gas leak, lubricant on CryoFit extremities
Aerospace 3/8” proof pressure, was soluble in hydrazine. No risk
Raumfahrt further quali- of contamination of propellant
Infrastruc- fication tests inside tubes because lubricant is
ture) planned. external to coupling ‘teeth’.
Matra-Mar-
coni Space 4PHS111 Ti -3Al-2.5V Hydrazine Gas Leak MMS reported leak rate of less Undetermined
(UK) 1/4”, 3/8” Ti-6Al-4V than 10-9 cc/s for a 4PHS111-04
(Now As- joining 2 Ti-3Al-2.5V tubes filled
trium) CP Ti, SS304 with helium at 387 bar (≈ poros-
ity of tube)

Boeing Space 4P02111 ¼” 304 Hydrazine Vibration, All tests completed satisfactorily Unknown
& Defence 1/8 Hard Thermal Cycle, Pegasus and GPS
Group 321 4X operating programs.
pressure (Sub-contract for
Lockheed Martin)
Primex 5PHS111 ¼” Ti 6Al-4V Hydrazine Proof Pressure All tests completed satisfactorily
Aerospace 304 Mass Spectrom- Leak and burst tests successful
Company 1/8 Hard eter Leak test, even on samples where assembly
Bending,Vibra- had been deliberately bent. Tests
tion, Torsion, concluded when tube burst at
Burst, Adjacent 23,500 psi
Weld

67 www.aerofit.com

GENERAL INFORMATION

CryoFit® Couplings for Space Vehicle Plumbing Systems

Company Product Propellant Tests Results Space Vehicle
Series and Tube Types Performed Applications

Sizes

NASA, 3PHS111 ½” 304 Undetermined Negative Pressure, GHe leak rate less than 1x 10-7cc/ Unknown
JFK Space 1/8 Hard Low temperature sec even when installed coupling
Center leak tests below martensitic transformation
temperature.

Ishikawa- 4PO2111 Commercial Undetermined Unknown Unknown Unknown
jima Harima 3/8” & 1/2” Stainless
Heavy Indus- Steel
tries

ESA/Dornier 4PHS111 Ti-3Al-2.5V Hydrazine Leak Test (Dowty) Satisfactory - approved for propel- XMM
/Fiat BPD/ 1/4” Vibration with lant tank repair.
Dowty Aero- Thermal Cycle
space superimposed
(ESA)

JPL Pasadena 4PHS111 Unknown Unknown Unknown Not communicated Mars Rover
Landing Vehicle

NASA – God- 4PHS111 Unknown Unknown Unknown Not communicated
dard Space
Center

Surrey Satel- 3PHS111 T1-3Al-2.5V Thermal Cycling Tests completed satisfactorily
lite Technolo- ¼” & 3/8” & CRES
gies Ltd

68 www.aerofit.com

GENERAL INFORMATION

Measurements of Electrical Resistance measured across assembled 3PHS111 coupling

CRES 21-6-9 Ti-3AL-2.5V

Tube Measured Resistance BAC5117 Tube Measured Resistance BAC5117
Size Test No. limit Size Test No. limit

milliohms avg milliohms 15908 milliohms avg milliohms
12 4 15910 3.51 12
15906 2.6 8 3.7 8
5 15930 3.27 2.98 5
4 15907 2.35 2.56 15931 3.45 3
15940 2.65 3 15832 3.6 2.32
15838 2.46
15946 2.65 6 15845 2.9
15865 2.68
15833 2.1 15866 3.2
15876 3.25
15840 2.1 15936 3.4
15950 2.35
6 15846 1.9 2.03 8 15965 2.35
15847 1.96 15972 2.34
2.22
15856 2

15869 2.11

15939 1.55 1.63

15951 1.61
8 15953
1.63

15954 1.63

15958 1.74

15852 2.1 15842 1.62

15857 1.6 15874 2.08 1.85
1.9
10 15870 1.2 1.45 10 15875
15871 1.18 15886 1.8

15881 1.26

15884 1.33

15849 1.1 15848 1.56

12 15911 1.08 1.07 12 15928 1.6 1.61
15925 1.03 15929 1.68

15926 1.05 15942 1.6

15964 0.9 15850 1.36

15969 0.94 15863 1.35

16 15989 0.85 0.88 16 15970 1.4 1.2

15995 0.86 15984 1.3

15996 0.86 15990 0.58

16229 1.73

20 16230 1.78 1.72 20
16231 1.65

16232 1.7

16236 1.69

24 16237 1.73 1.82 24
16238 1.95

16239 1.9

69 www.aerofit.com

Al. Alloy 6061-T6

Tube Size Test No. Measured Resistance BAC5117
limit milliohms
15912 milliohms avg
1.3
15916 2.37 0.95
0.75
4 15917 2.17 2.01
1.84
15918
15841 1.66
15867
15868 2.15
15878
15880 1.44
15882
15883 2.2 1.98
6 15927 2.72
15938
15959 1.69
15960
15971 1.27
15843
15873 2.38
15877
15885 0.63
15887
15897 0.54
8 15921 0.4 0.6
15922
15923 0.68
15862
15909 0.75
15935
15952 0.38
15851
15991 0.48
16014
0.36
16243
16244 1.06
16245 0.46 0.48
10 16246
16247
0.38

0.43

0.37

0.38

0.61

12 0.44 0.42
0.36

0.27

0.4

16 0.71 0.46

0.28

20

0.23
0.4
24 1.64 0.63
0.17
0.71

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Comparative Measurements of Electrical Resistance measured across assembled CryoFit couplings and CryOlive
/Lightweight Union connections

CryoFit CryOlive and Lightweight Union

Tube Size Installed Tube only (control) Installed Tube only (control)
2.63
-4 1.8 1.32 2.7 2.74
-6 0.95 1.36 1.08 1.42
-8 0.95 0.96 1.9

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GENERAL INFORMATION

Corrosion Resistance of TiNi Alloys

TiNi alloys in natural atmospheres and waters are generally more corrosion resistant than 316 stainless steel but
not as resistant as pure titanium. A passive oxide/nitride surface film is the basis of the corrosion resistance of
these three materials. Specific environments can cause the passive film on TiNi to break down , opening the al-
loy to attack. The accumulated experience with TiNi will be presented as corrosion by atmospheres, by waters,
by organic chemicals, by inorganic chemicals or by biological environments.
Corrosion by Atmospheres
Polished TiNi remains shiny in air from ambient temperatures up to about 100ºC at which temperature the
oxide/nitride surface layer slowly thickens giving the interference colors. Up to about 700ºC, a tight, thin,
blue-black oxide/nitride film protects the TiNi. Above 700ºC, the layer thickens into a more porous brown and
yellow scale. No absorption of oxygen into the alloy or internal oxidation occurs, thus TiNi behaves more like
stainless steel at elevated temperatures than like titanium alloys.
If TiNi at ambient temperature is impinged by pure oxygen gas at progressively higher pressures, flashes and
sustained burning begin above 150 psi absolute. By 500 psia, 16 out of 20 tests produced flashes and burn-
ing.
When TiNi is heated to 700ºC in pure nitrogen at atmospheric pressure a beautiful gold-colored, somewhat
brittle, surface layer forms.
The interaction between hydrogen and TiNi is sensitive to hydrogen concentration, pressure, and temperature.
TiNi remains ductile after having been heated to 750ºC in hydrogen gas at atmospheric pressure , then returned
to room temperature. However,TiNi exposed to hydrogen gas at 360ºC becomes brittle and crumbly. If nascent
hydrogen is charged into TiNi, a brittle surface layer forms and thickens with time. This will be discussed in
more detail in the “waters” section. Also, if TiNi tensile samples are elongated while surrounded by hydrogen
gas at 7,000 psi, brittle failure occurs; immediately upon reducing the pressure to one atmosphere, the failure
mode is again ductile.
The presence of gaseous hydrogen fluoride in damp air at ambient temperatures has caused surface etching and
stress corrosion cracking in bareTiNi couplings. Condensation was occurring on the couplings, however, so this
should probably be considered as attack by hydrofluoric acid.
Corrosion by Water
Tinel is not attacked by fresh water. Even in pressurized boiling water (PBW) at 300°C for eleven months,Tinel
gained only 15% as much weight as Zircaloy-2. The same sort of PBW at 340°C and 20 ml / kg H2 causes little
damage. Water at 360°C with 100 ml H2 / kg causes Tinel to crumble to dust; the diffraction pattern of the dust
shows only the presence of TiH2 and Ti2Ni. Tinel resists attack while immersed in flowing sea water. However,
in stagnant sea water as in crevices, the protective film can break down, resulting in pitting. Tunneling corrosion
can occur when Tinel is exposed to a marine environment which cycles from salt mist in the cool of the day to
evaporation during the heat of the day. Small, residue-free pits form on the weather surface while branching
tunnels penetrate into the bulk of the metal (tunneling corrosion has been reported in austenitic stainless steel
under similar conditions). This same type of corrosion occurs when the salinity exceeds twice that of sea water
and the pH drops below two. Addition of sodium hydrochloride to sea water causes the same phenomenon. Salt
spray tests are often used as an accelerated indication of longer term corrosion resistance. Tinel passes these tests.
In one case CryoFit coupling assemblies were subjected to a six-day cyclic test in 5% salt plus sulphur dioxide
spray. All assemblies passed the test. A year later one of the unwashed assemblies was found to have cracked.
Sectioning revealed that tunneling occurred throughout the coupling, starting from the inside where electrolyte
had been trapped between the coupling and the tube.
Special effects have resulted from electrical currents and saline solutions. A cycling plus-minus 5 volt applied to
Tinel in a 150-ohm saline solution caused grain boundary cracking within 150 days. Also, when Tinel was

72 www.aerofit.com

made the cathode in a cell with a saline electrolyte and a voltage which caused hydrolysis of the water, the Tinel
was charged with nascent hydrogen. For several days after removal from the cell, chips of Tinel would forcibly
pop off the surface, especially at corners.
Products for Demanding Marine and Industrial Applications
SMA Fittings for marine and industrial use provide an innovative means to permanently join pipes and tubes
in critical high-performance systems. SMA Fitting’s reliable performance and reduced installation cost make it
superior to welding or brazing methods for both original construction and maintenance in a variety of applica-
tions.
Typical marine applications for SMA Fittings include hydraulic, compressed air, fire fighting, and gauge line
systems. SMA Fittings are used in over 20 different ship classes, including the DDG-51, CG-47, and LHD-1
classes.
SMA Fittings are also used in both nuclear and fossil fuel electric power generating plants for feed water, control,
and discharge systems.
Corrosion by Organic Chemicals
Acetic acid, CH3COOH, attacks Tinel at a modest rate of one to three mils per year (mpy) over the temperature
range 30°C to the boiling point and the concentration range 50% to 99.5%. The attack is fastest at the lowest
concentration at the highest temperature and at the highest concentration at the lower temperature. Seventy per
cent acetic acid with 0.1% formic acid, HCOOH, attacks at the same rate as 70% acetic acid: 0.3 mpy.
A study reported 5 mpy attack rate in 0.5M oxalic acid, H2C2O4, at 50°C.
Methanol, CH3OH, has a mixed history. A steel pipeline on the bottom of the North Sea was used to deliver
methanol as an anti-freeze to gas wells. An undersea repair was made to the line using a Tinel coupling which
served without problems for several years. A similar installation on a new drilling platform off Scotland leaked
within hours after being filled with methanol. This occurred again with several methanol line couplings under
Lake Erie. Tunneling of a type similar to that found with special marine exposure situations was the cause. Low
concentrations of water and halides in methanol cause attack on titanium alloys, whereas pure methanol or
more contaminated methanol does not. Perhaps this is true for Tinel, too.
A 15% solution of iodine in polyvinyl pyridine at 37°C and at 60°C caused severe cracking of Tinel couplings
within one month.
Tinel was not attacked after three months in a urea, CO(NH2)2, solution at 100°C.
The hydraulic fluids, Skydrol 500 and Aerosafe 2300, at 125°C and 135°C, respectively, for 20 hours caused
no attack on Tinel couplings. This preliminary observation has been corroborated by many years of satisfactory
Tinel service aboard aircraft.
Corrosion by Inorganic Chemicals
Tinel has been exposed to a number of different inorganic chemicals singly or in combinations and mostly as
aqueous solutions. The observations will be presented in alphabetical order:
Aluminum nitrate at 6.2M concentration and 50°C attacked Tinel at a fraction of a mil per year. However, 0.3M
A1 (NO3)3 + 0.6M HF + 12M HNO3 attacked at 1300 mpy.
At 50°C, 6.2M ammonium thiocyanate, NH4SCN did not attack Tinel.
Boron trifluoride plus hydrogen fluoride dissolved in water condensate on CryoFit couplings attacked at 20 to
40 mpy in a pitting mode and led to stress corrosion cracking.

73 www.aerofit.com

Bromine dissolved in methanol can chemically polish Tinel.
Tinel has been exposed to liquid cadmium with no ill effects.
Calcium hypochlorite at 70°C attacked at 15 mpy.
Chromic acid at 10% concentration and 70°C attacked at 1 mpy; 50%, at 2 mpy. One percent chromic acid plus
five per cent hydrochloric acid attacked at 18.5 mpy. Chromic acid at 6.8% plus 1.5% ferric chloride plus 9%
hydrochloric acid attacked at 2,200 mpy. Half a per cent chromic acid plus 5% sulfuric acid attacked at 1 mpy.
Copper chloride at 70°C attacked at 215 mpy.
Ferric chloride at 8% concentration and 70°C attacked at 350 mpy. 1.5% ferric chloride +2.5% HCl attacked at
110 mpy; +5% HCl, at 120 mpy; +10% HCl, dissolved the Tinel!
The attack of hydrochloric acid on Tinel has a strong dependence on temperature, acid concentration, and the
specific alloy composition. With 3% HCl at 100°C and a range of alloy compositions, the rate of attack was
as low as 14 mpy and as high as 129; with 5% HCl the rate was from 14 to 1,667 mpy. At room temperature
with 7M HCl,Tinel “A” lost from 9,000 to 18,000 mpy. Preliminary results indicate that gaseous HCl can cause
stressed CryoFit couplings to fail within minutes. Curiously, equal parts of concentrated hydrochloric acid,
concentrated nitric acid, and water at room temperature remove the heavy scale from hot worked Tinel without
noticeable attack of the alloy.
Combinations of hydrofluoric acid, nitric acid, and water give some of the most useful solutions for chemical
surface treatment of Tinel. Descaling, metallographic etching, and chemical polishing at various rates can be
achieved by adjusting the ratios. One part of 40% HF, one part concentrated HNO3, and two and a half parts of
concentrated H2SO4 also brightens Tinel.
Hydrazine did not attack Tinel “A” in a 49-day test at 85°F. A 16-week test at 70°F also caused no attack.
Nitric acid is more aggressive toward Tinel than toward austenitic stainless steel. At 30°C, 10% HNO3 attacked
Tinel at 1 mpy; 60%, at 10 mpy; 5% HNO3 at its boiling point attacked at 80 mpy. In another test at 50°C, 3M
HNO3 attacked at 11.5 mpy, 7.5M at 29 mpy; and 12M, at 30.5 mpy. Red fuming nitric acid at room tempera-
ture caused extensive weight loss and pitting of Tinel within 48 hours.
The combination of 7.5M nitric acid with 0.02M sulfuric acid caused just 9 mpy attack on a Tinel coupon.
However, a Tinel coupling on a 304 stainless steel tube lost 29 mpy, whereas the stainless steel lost none.
Nitrogen tetroxide, N2O4, caused no attack of Tinel during a 49-day exposure at 85°C.
Attack by phosphoric acid is a strong function of concentration and temperature. At 30°C, 5% H3PO4 attacks
Tinel at 0.5 mpy; for 50% H3PO4 at the boiling point the rate is 2,300 mpy. A CryoFit coupling im-mersed in
105 weight per cent H3PO4 at 400°F “completely dissolved within 48 hours”.
Potassium hydroxide does not seem to attack Tinel. Seven hundred twenty hours exposure to 6M KOH at 50°C
caused no loss of Tinel.
A CryoFit coupling joining two 304 stainless steel tubes was pressurized with helium. The assembly was im-
mersed in liquid sodium at 482°C for 30 minutes, then returned to room temperature. On the sixth cycle the
assembly leaked. The failure was attributed to creep; attack of the Tinel was not reported.
Sodium hydroxide at 20% concentration and 30°C attacks TiNi at 0.4 mpy; at the boiling point, 1.6 mpy.
Binary TiNi is attacked by 5 wt. sulfuric acid at 100°C at 8,200 mpy; by 10 wt. %, at 14,300 mpy. For highly
alloyed TiNi, 1% sulfuric acid at 30°C attacks at 0.4 mpy; concentrated sulfuric, at 84 mpy. At its boiling point,
0.1 % sulfuric acid attacks highly alloyed TiNi at 0.3 mpy; 5% sulfuric acid, at 460 mpy. At 50°C, 0.3M sulfuric
acid attacks Tinel at 3 mpy; 3.0M, at 670 mpy.

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Oxygen Compatibility
SMA products manufactured from Tinel have been found to be compatible with oxygen system applications due
to their geometry and passive protective oxide layer
We have carefully researched the topic and concluded that there is no reasonable possibility of this occurring.
Consider the following:
1. Spontaneous combustion of highly reactive materials is known -- fires from zirconium machining chips

caused serious damage and injuries in the 1960’s at the Bettis Atomic Power Labs in West Mifflin, PA; and
explosions involving aluminium powder are certainly common -- in fact, the self combustion of aluminium
provides the fuel for the space shuttle booster rockets. NiTi is indeed highly reactive, but far less so than is
pure titanium or aluminium. We have done a careful search of the literature on NiTi and found no published
or verifiable evidence of self-combustion with oxygen. The only reference to the effects of NiTi in oxygen
is an obscure letter written from the NASA Marshall Flight Center to Raychem in 1971. It was found that an
unidentified NiTi alloy sustained some reaction in gaseous and liquid oxygen above 150 psia. However, it
must be noted that neither the alloy, the test conditions or sample configurations were documented. If NASA
conducted the tests according to the ASTM test method, which involves the use of dropped weights, to obtain
these results, then there would seem to be absolutely no correlation to your fluid fittings applications.
2. All known combustion events of similar materials have involved forms such as fine powders or machining
chips, where the surface area to volume ratios are very high. The products you use, however, are bulk prod-
ucts and have nowhere near the surface area to volume ratio required to self-combust. Roughly speaking,
the ratio in a -6 CryOlive (3/8” I.D.) is about 10,000 times lower than that which would be found in a fine
powder. Very fine sheet and wire products would have a higher propensity to combust than would the CryO-
live, but still would be considered safe by any measure. Keep in mind, sheets of 0.1mm thicknesses and wires
of 0.02mm diameter have been in use for some time without adverse observations.
Note that it is possible for shapes to have very fine burrs, depending upon manufacturing methods. Fine
burrs are candidates for combustion, but would not trigger a general combustion event. Combustion de-
burring is, in fact, a common and harmless production method used with stainless steels and like materials.
3. Combustion can only happen in the absence of a passive oxide layer. Aluminium powder, for example, is
explosive after atomization in high purity helium, but not after atomization in air. Aluminium tubing is com-
monly used upon aircraft even though aluminium is the most reactive metal known -- many more times so
than is nickel-titanium. Safety, in this case, is provided by the passive oxide layer formed by nature itself dur-
ing the processing of the tubing. Nickel-titanium is well known to have such a protective layer. New metal is
exposed by machining but the oxide layer is immediately reformed due to exposure to coolant water and air.
Moreover, your finished products are heat treated which eliminates all chance that parts go unprotected.
4. Combustion of NiTi is known in one particular case: if elemental ingredients are pressed together in the
absence of oxygen, then heated rapidly and adiabatically to 720°C, they can “combust”. That is, they will
chemically combine in an exothermic manner, heating specimens beyond their melting points. This, clearly,
is completely irrelevant to your situation since you use pre-alloyed material. We mention this simply because
there are literature references to such “combustion synthesis” methods which might tend to mislead people
into believing this is a problem with the alloy in general.”

75 www.aerofit.com

GENERAL INFORMATION

Seal, Hold and Flex

Seal, hold, and flex are the essential tasks that any flareless sleeve must perform, in addition to properly mating
with the flareless fitting end. Sealing in this context refers to the sleeve-to-tube juncture. Holding refers to the
sleeve’s ability to withstand various operating loads, i.e. tension and torsion. Flex refers to the sleeve’s ability to
withstand flexural loads. To aid understanding of how CryOlive sleeves work, Figure 7 identifies the regions of
the sleeve responsible for the various tasks it must perform.

Figure 7

TASK REGIONS OF A CRYOLIVE SLEEVE

MATE HOLD FLEX
(NOSE) (BODY) (TAIL)

SEAL (TEETH)

Sealing: CryOlive Sleeves

The tube-to-sleeve seal occurs at the teeth, and is a pressure boundary. No leakage is allowed. A robust seal is
essential. Sealing is a task at which CryOlive sleeves excel because of shape-memory. To understand the role
shape-memory plays in sealing, it is useful to examine the stress-strain curves for the sleeve and the tube during
installation (constrained recovery). These are shown in Figures 8a and 8b respectively.

76 www.aerofit.com

Figure 8a Figure 8b

3

6f f
2
Tube Yields

Sleeve Contacts Tube Sleeve Contacts Tube

1 54 1

SLEEVE TUBE

In Figure 8a, sleeve contact with the tube begins at point 5. In Figure 8b sleeve contact with the tube begins
at point 1. After contact, stress builds rapidly in both the sleeve and the tube. Looking at the tube stress/strain
curve, the tube begins to yield and continues to yield until equilibrium is reached between the tube and the
sleeve. At this point recovery ceases. It is very important to note that when recovery ceases there is no let-off, or
springback in either the tube or the sleeve, and that the final stress in each remains high. The remaining high
interfacial pressure between the tube and the sleeve is the paramount feature of the CryOlive SMA sleeve. It is
this interfacial pressure, transmitted primarily through the teeth, which creates and sustains the metal-to-metal
seal between the tube and the sleeve.

Sealing: MS 21922 Flareless Sleeves

Sealing with MS 21922 sleeves is accomplished quite differently. Figure 9 shows a detail of the MS 21922 sleeve
before and after installation. MS 21922 sleeves are often called “bite-type” sleeves. When the sleeve is installed
on the tube, the nut (or pre-setter) pushes the sleeve towards the end of the tube and the nose of the sleeve is
forced into the tube by the conical taper of the fitting end. The small, sharp, case-hardened cutting edge on the
inside surface of the nose digs or “bites” into the tube surface and throws up a burr, hence the term “bite-type”
sleeve. The bite is where the sleeve-to-tube seal occurs.

Figure 9
MS 21922 SLEEVE DETAIL

PRE-INSTALLED INSTALLED

CUTTING EDGE

MS 21922 sleeves work satisfactorily on soft steel and aluminum tubes but don’t work well on harder tube ma-
terials, (21-6-9 CRES and 3AL-2.5V titanium, for example) as they can’t bite into them with a high degree of
consistency and reliability.

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Holding: CryOlive Sleeves

As previously stated, holding refers to the sleeve’s ability to withstand all of the various operating loads, i.e. ten-
sile and torsional loads caused by fluid pressure, structural flexing, and vibration. With CryOlive sleeves, there
are two mechanisms doing the holding: mechanical interference and friction. Mechanical interference is cre-
ated as the sleeve swages the tube into a drawing-die configuration. The interfacial pressure, or radial loading,
between the sleeve and the tube creates friction forces which oppose axial and torsional loads.
Holding and sealing are both aided by tooth “bite”. The sleeve’s teeth concentrate the recovery forces and actu-
ally indent the surface of the tube as the sleeve recovers. This creates additional mechanical interference between
the sleeve and the tube and enhances the tensile load carrying ability of the sleeve. Figure 10 contains a cutaway
view of a CryOlive sleeve installed on tube.

Figure 10
INSTALLED CRYOLIVE SLEEVE

Empirical and analytical study of the interaction between the tube and the teeth has led to thorough under-
standing of the tooth geometry and spacing needed to produce the optimum drawing-die configuration. State-
of-the-art finite element analysis involving plastic deformation analysis with slide lines was employed to opti-
mize the configuration of the teeth for optimum “bite”.
The sealing and holding ability of CryOlive sleeves are both entirely dependent on the sleeve’s ability to swage the
tube. With this in mind, many who are unfamiliar with shape-memory technology feel compelled to ask, “Will
the sleeve always swage the tube enough?”, and the converse, “Can the sleeve swage the tube too much?”

Holding: MS 21922 Flareless Sleeve

With MS 21922 sleeves there are also two mechanisms providing holding ability. There is mechanical inter-
ference resulting from the deformation that takes place when the sleeve is set, and there is the “bite” that was
described in the discussion of sealing. As mentioned previously, the bite isn’t good on hard tubes.
Taking these questions one at a time, the answer to the first question is yes, the sleeve will always swage the tube
sufficiently. Two things are required for proper swaging: sufficient force, and sufficient motion. As was men-
tioned early on, the alloy can develop hoop stress upwards of 60 KSI (412 MPa) during constrained recovery.
This ability is an inherent property of the alloy, and is a function of alloy composition and processing. Consistent
alloy exhibits consistent shape-memory behavior. Alloy production, processes, controls, and quality checks are
utilized to assure consistent material. Determination of the force required to swage a tube of a given material,
strength, and stiffness is relatively straightforward, and burst performance requirements, typically 4X, dictate
the amount of swaging necessary to meet the requirements. Conventional calculations are then employed to
determine the cross sectional thickness of alloy required to do the job. In general, ensuring sufficient swaging
involves 1) balancing the stress the shape-memory alloy can produce with the force required to swage a given
tube via sleeve cross section, and 2) sizing the sleeve’s as-machined ID so as to effectively use the available shape-
memory motion.
As mentioned earlier, CryOlive sleeves were designed to be used with most common aerospace tubing: 6061-
T6 aluminum, 304 1/8 hard CRES, 21-6-9 CRES, 3Al-2.5V CWSR titanium, etc. As far as tube swaging is con-
cerned, the sleeve’s cross section and ID are sized such that even at their worst-case tolerance extremes, i.e. the

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minimum cross-section and the maximum tooth ID, the sleeve has enough stored energy and motion to swage
the strongest, stiffest tube, i.e. 4000 psi rated CWSR titanium tube per AMS4944, with the tube in its least favor-
able condition, i.e. minimum OD, maximum wall, and maximum yield strength.
The following example illustrates how a sleeve is sized so as to swage properly under adverse tolerance stack-ups.
A size -20 shape-memory alloy sleeve is used in this example.

Tube OD: 1.249-1.254
Machined Sleeve ID: 1.186-1.192
EXPANDED SLEEVE ID 1.254
1. Max Tube Diameter: +.005
2. Min. Clearance at Installation: 1.259
3. Required Min Expanded Sleeve ID:

REQUIRED SLEEVE MOTION 1.249 X .02 = .025
4. Min Required Tube Swaging (2%): 1.192 X .02 = .024
5. Unresolved Sleeve Recovery (2%): 1.254 - 1.249 = .005
6. Tube Tolerance: 1.259 - 1.254 = .005
7. Installation Clearance: 4 + 5 + 6 +7 = .059
8. Necessary Sleeve Motion:

EXCESS MOTION
9. Min. Available Sleeve Motion: 1.259 - 1.190 = .069
10. Necessary Sleeve Motion: -.059
11. Excess Available Motion: .010
Dimensions in inches.

Note the following about the preceding exercise:
2% swaging is a nominal figure considered by Aerofit, Inc. engineers to provide good “holding” ability. Note
that 2% swaging is based on the minimum OD tube and is therefore conservative. 2% unresolved recovery refers
to the difference between the as-machined, or free-recovered, sleeve ID and the as-installed ID. 2% is a nominal
figure considered by Aerofit, Inc. engineers to provide good sealing ability. Note that 2% unresolved is based on
the max machined sleeve ID, and is also conservative.
Excess available motion (.010 in this example) and the unresolved recovery ensure that the sleeve will always
swage the tube sufficiently.
A size -20 sleeve is used as an example here but the situation is typical. There is excess available motion for all
sizes of sleeves.
Moving now to the second question, “Can the sleeve swage the tube too much?” The answer is no, but this an-
swer requires some qualification. The sleeve can only recover to its original, as-machined size. This can only
occur if there is little or no resistance from the tube or no tube at all.
Low-strength, low stiffness tubes are not ideally suited to CryOlive installations, nor to any other flareless design,
for that matter. Consider 1.000 x .020 wall, 5052-0 aluminum tube, for example. This is a very low strength,
low stiffness tube. This tubing would present little resistance to the swaging force of a CryOlive sleeve. The
sleeve would recover virtually all the way to its as-machined ID resulting in very little unresolved recovery. The
benefits of the “live crimp” action that results from unresolved recovery are lost in this situation.
Other questions that have been raised with regard to swaging are, “Is it possible for the nose to swage so much
as to lose its ability to mate with the MS fitting end?”, and, “Can the sleeve body swage to the point where it
would not have adequate contact with the shoulder of the coupling-nut?”. The answer on both accounts is no.
These possibilities were addressed in the sleeve design by configuring the nose so that it is incapable of swaging
upon recovery, and by ensuring there was adequate overlap of the nut and sleeve shoulders after recovery.

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Flexing: CryOlive Sleeves

Referring to Figure 7, note the tail region of the sleeve. The tail is responsible for flexure performance. The
tail bleeds off bending stresses encountered by the tube. Firm, uniform contact between the tube and the tail
is required to effectively transfer the stresses from the tube to the sleeve. Here the interfacial pressure of the
shape-memory effect is tailored via tail geometry to provide gradual, uniform support of the tube. In addition
the ID of the tail is coated with a solid film lubricant to combat fretting between the sleeve and the tube. Flex-
ural endurance of CryOlive shape-memory sleeves is often limited by the flexural endurance of the tube. 4000
psi rated CryOlive sleeves, for example, were qualified on 3Al-2.5V titanium tubing in flexure with a minimum
of ten million cycles at 20,750 psi minimum dynamic bending stress. No other 4000 psi rated separable fit-
ting is qualified at this stress in every size. Figure 11 and Figure 12 display CryOlive sleeve flexure results from
qualification testing on 4000 and 3000 psi rated CWSR titanium tube, respectively. CryOlive sleeves meet the
flexure requirements of AS18280.

Figure 11
4000 PSI QUALIFICATION FLEXURE TEST RESULTS

400C0RPYSOI LCIWVESRSLTEITEAVNEIUSMONTUBE

STRESS (PSI) 50000 -4 test halted; no failure
40000 -6 test halted; no failure
30000
-6
-8 test halted; no failure

20000

10000 456 7 RUNOUT BEYOND
03 10,000,000 CYCLES
CYCLES
8

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Figure 12
3000 PSI QUALIFICATION FLEXURE TEST RESULTS

300C0RPYSOI LCIWVESRSLTEITEAVNEIUSMONTUBE

50000

40000 -4
30000 -4 test halted; no failure

STRESS (PSI) -6
-6 test halted; no failure
-8
-8 test halted; no failure

20000

10000

03 RUNOUT BEYOND
10,000,000 CYCLES

45 67 8

CYCLES

Mating: CryOlive Sleeves vs. MS 21922 Sleeves

When mated, the contacting surfaces of a flareless sleeve and flareless fitting end form a pressure boundary.
Proper mating is essential. To hold pressure, the surfaces must contact uniformly and be held together firmly.
The sleeves and fittings are machined within certain tolerances. Proper mating must occur for any combination
of permissible tolerance conditions of both the mating parts. Flareless connections are required by AS18280 to
be capable of eight repeated assemblies.
Proper mating must be established each time the joint is reassembled. In actual usage, reassembly may involve
replacement of the fitting, in which case the sleeve may encounter a fitting end that is likely to be in a slightly
different tolerance condition than its predecessor. So proper mating must occur 1) for any permissible toler-
ance condition of both parts, 2) with repeated assembly, and 3) if components are interchanged. To accomplish
this, the design and/or the components need to have some “give” in them. MS sleeves and CryOlive sleeves
both provide the necessary “give”, but differ in one key aspect: MS sleeves do not have positive stop whereas
CryOlive sleeves do.
Because they have no positive stop, MS sleeves are susceptible to problems resulting from over torquing. Torqu-
ing beyond the prescribed limits forces the MS sleeve deeper and deeper into the conical taper of the fitting end
and results in deformation of the sleeve. The deformation can cause leakage or if the over torquing is severe the
sleeve can actually buckle. In either case the deformation interferes with proper mating upon reassembly with
the same fitting or a different fitting.
CryOlive sleeves are not susceptible to over torquing. The shoulder on the sleeve butts against the end of the
fitting as the joint is torqued up and thus limits the penetration of the nose into the fitting end, even if the joint
is overtorqued.

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GENERAL INFORMATION

Common Questions
If I let a coupling recover (shrink), can I put it back in liquid nitrogen to re-expand it?

No, it must be returned to the distributor for re-expansion. But make sure that it is returned, because the ability
to re-expand couplings ensures that the investment in the product is not lost if it recovers for whatever reason.
Do not throw away/dispose of recovered couplings!
If I let a coupling recover on a tube without it being properly positioned, can I remove the coupling by putting it back in
liquid nitrogen?
No, once the coupling shrinks on a tube, the only way to remove it is to cut it off the tube.
If the joint is cooled below the transformation temperature of the alloy, will the coupling fail?
No, the coupling will become relatively weaker at cryogenic temperatures, but will not fail. Recall that the only
way a coupling can be expanded at low temperatures is by mechanical force, as in the mandrel used in the man-
ufacturing process. The low temperature itself will not cause the coupling to expand. Indeed NASA have tested
couplings at -320ºF (-196ºC) and recorded Helium leak rates of less than 10-5 cc/sec.
Is there a corrosion problem between the coupling (which contains titanium) and aluminum tubing?
No. Even though titanium and aluminum are at opposite ends of the galvanic scale, testing and thirty years of
experience of using the alloy on aluminum have shown that corrosion problems do not readily occur. The key
is properly protected aluminum tube. Corrosion problems on unprotected aluminum tube will occur with any
coupling, not just SMA products!
How long do I have till the coupling recovers?
The complete answer is it depends on the size of the coupling which translates into the mass of the metal. The
tube material can also influence recovery with aluminum transferring temperature the quickest and titanium
transferring temperature the slowest. But on the average, you should have about 30 seconds to install a coupling
prior to recovery. This time can be increased by cooling the tube prior to installation.
What is the shelf life of the couplings in storage?
Unlimited - provided the liquid nitrogen in the storage vessel is kept refilled.
Are there Shape Memory Alloy tees and elbows too?
Because of the limitations of the expansion process ( the final stage of manufacturing of all Shape Memory Al-
loy couplings ) it is not possible to have tees and elbows made from Shape Memory Alloy - they would in any
case be somewhat complex to install. However, Aerofit offers a wide range of CryoFit-compatible tees, elbows,
crosses, bulkhead fittings, in both permanent connection styles and with threaded interface to some ports for
connection to Flared, Flareless and Beamseal systems.These compatible fittings are generally made from Ti-6Al-
4V alloy for maximum strength and lowest weight and come ready marked and prepared for use with the rel-
evant CryoFit couplings. They are fully qualified to the relevant industry or in-house specifications for use with
CryoFit couplings.

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Can CryoFit, Cryolive and CryoFlare be used for Battle Damage Repair?
Absolutely, CryoFit can often provide the quickest and most effective permanent repair to any damage, whether
in a military or civilian context. It has the crucial advantage over all other systems of requiring much less disas-
sembly of surrounding components.
CryOlive and CryoFlare are even simpler to install and can be used to provide the mating interface for a tempo-
rary repair with a flexible hose.
Can they be installed while wearing NBC (Nuclear, Biological, Chemical Warfare) Protective Equipment?
Yes, the simplicity of the installation process means that CryoFit, CryoFlare and CryOlive are ideal for installa-
tions where vision and manual dexterity are impaired. As an added benefit the standard NATO issue inner and
outer glove combination can also be used for short periods with Liquid Nitrogen without any additional protec-
tion.
Are CryoFit and CryOlive joints electrically conductive? Do they meet requirements for Lightning Strike?
Yes,Tinel has a resistivity of 100 x 10-6 ohm-cm. The resistance of assembled CryoFit joints is only very slightly
higher than for tube of an equivalent material, size and length. Both CryoFit and the separable CryOlive/Light-
weight Union joint easily meet the requirements of BAC5117.
QA Summary

• A coupling which has warmed up cannot be re-expanded by re-immersion in liquid nitrogen.
• It is impossible to install a coupling on to a tube assembly unless it is in the expanded (as-delivered)
condition.
• This characteristic acts as fail-safe: a coupling which has not been expanded, or which has been allowed to
warm prematurely, cannot be installed.
• The characteristics of shape-memory-alloy are such that a correctly installed coupling will not leak.
• Only a visual inspection of the position of the coupling with respect to the installation witness marks is
required.
• Additional examination by radiography or endoscope provides no additional information and is of no
value.

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Aerofit, Inc.
APT Laboratory
1425 South Acacia Avenue
Fullerton, California,92831 USA
www.aerofit.com
www.aptlab.com