Bsi bs c 22 1995 (2000) iso 9475 1994

BRITISH STANDARD AEROSPACE SERIES BS C 22 1995 ISO 9475 1994 Test methods for aircraft inner tube and tubeless tyre valves — Cores and caps Reproduced by IHS under l icense with BSI Uncontrol led Copy[.]

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Test methods for

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This Bri shStan ard, ha ing

b en pre ared u der the

directonof the Eng ine ring

SectorBo rd (E/ -), was

publishedu der the

authoriyofthe Stan ards

Bo rd an comes

into efect on

1 April1 9

The folowing BSI references

relate to the work on this

stan ard:

Commi e reference ACE/ 59

Draft for comment9 /71 1 5DC

ISBN 0 5 0 2 0 6 0

The prep ration of this BritishStand ard was entrusted to Technical

Commit e ACE/59, Air raft ty res, rims an as ociated eq uipment, upon which

the folowing bodies were represented:

British Airway s

British Rub er Man facturer ’ Association Ltd

Civ il Av iation Authority ( Airworthines Div ision)

Ministry of Defence

Retrea Man facturer ’ Association

Society of British Aerosp ce Comp nies Ltd

Am endm ents is ued sinc publ cation

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Pag e

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This BritishStand ard has be n prep red b Technical Commit e ACE/59 It is

identical with ISO9 7 :19 4, A ir cr a ft in er tube a nd tubele s tyr e va lve —

Cor es a nd ca ps— Te t method s, publshed b the International Org anization for

Stand ard ization ( ISO)

The Tech ical Commit e has rev iewed the prov isions of ISO3 :19 4 and

ISO4 :19 4, to which normativ e reference is ma e in the text, an has d ecid ed

that they are ac epta le for use in conju ction with this stand ard

A British Stand ard d oes not purport to includ e al the neces ary prov isions of a

contract User of British Stand rd s are responsible for their cor ect a plcation

Com pl anc with a British Standard does not ofitself confer im m unity

f om leg al o l g ations

Cros - referenc s

Inte national Stand rd Cor esp nding BritishStand rd

ISO815:19 1 BS9 3 Physica l te tng o r ub er

Part A6:19 2 Method fr d eter mina tion o compr es ion

s t a t a mbient, eleva ted o low temper a tur es

( Id entical

ISO8 8:19 5 BS27 2 Method s o te tng pla stc

Par t3 Me ha nica l pr oper tie

Method3 5 B:19 2 Deter mina tion o ind enta tion

ha r d ne s by mea ns o a d ur ometer (Shor e ha r d ne s)

Sum mary of pag es

This document comprises a f ont cov er, an insid e font cov er, p g esi andi ,

p g es1 to4, an inside b ck cov er and a b ck cov er

This stand rd has be n up ated ( se copy rig ht d ate) an ma hav e ha

amendments incorporated This wi l be indicated in the amendment ta le on the

inside f ont cov er

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1 Scope

This International Stand rd specifies the test

method s used for v alv e cores an ca s for air raft

ty res, with or without in er tubes, and minimum

airtig htnes stand rds It constitutes a d etaied

method al owing products to be ev aluated on the

same b sis, and results to be comp red

The fol owing stand ard s contain prov isions which,

throug h reference in this text, constitute prov isions

of this International Stand ard At the time of

publcation, the editions ind icated were v ald All

stand ards are subject to rev ision, and p rties to

ag re ments b sed on this International Stand rd

are encourag ed to inv estig ate the pos ibi ty of

a ply ing the most recent editions of the stand rds

indicated below Member of IEC and ISO maintain

reg ister of cur ently v ald International Stand ards

ISO3 :19 4, R ub er , vulca nized o

ther mopla st c— Deter mina tion o tensie

str es -str a in pr oper tie

ISO4 :19 4, R ub er , vulca nized o

ther mopla st c— D eter mina tion o ha r d ne s

(ha r d ne s betwe n10 IR HD a nd100 IR HD )

ISO815:19 1, R ub er , vulca nized o

ther mopla st c— Deter mina tion o compr es ion s t

a t a mbient, eleva ted o low temper a tur es

ISO8 8:19 5, Pla st c a nd ebonie—

Deter mina tion o ind enta tion ha r d ne s by mea ns o

a d ur ometer (Shor e ha r d ne s)

3 General

For the test methods, the requirements laid down

u der the test cond itions are oblg atory The

procedure an certain a ditional per ormance

requirements shal be fixed b ag re ment betwe n

the v alv e man facturer an the clent, with an

oblg ation to me t the minimum airtig htnes

requirements d efined in this International

Stand ard

4 Valve cor s

4.1 Types of tests

Air raft ty re v alv e cores shal be submit ed to the

fol owing tests:

a) tig htening torq ue test(4.4.1);

b) washout test( 4.4.2);

c) blowout test( 4.4.3);

d ) pres uriz d pulse test(4.4.4);

e) env ironmental tests at low

temperature( 4.4.5);

f) env ironmental tests at constant hig h

temperature(4.4.6);

g ) env ironmental tests at peak hig h

temperature(4.4.7)

4.2 Minim um airtig htnes requirements

Valv e cores shal be rejected if the leakag e rate

d uring tests is g reater than0,2cm

3

/ min

4.3 General test conditions

Unles otherwise specified , al tests shal be

conducted u der the fol owing conditions:

a) ambient temperature and pres ure;

b) v alv e cores shal be instaled in a six -position

manifold as shown in Fig ure 1;

c) tig htening torques for cores with elastomeric

v alv e seats shal be betwe n0,17N·m

and0,3 N·m;

d) tig htening torq ues for cores with metal

( orelastomeric plus metal stop) v alv e seats shal

be betwe n0,3 N·m and0,5 N·m;

e) the pres ure insid e the manifold shal

be38 0kPa;

f) airtig htnes shal be v erified b immer ing the

core in water, acetone or alcohol

4.4 Test m etho s

4.4.1 Tight ening t orque te t

4.4.1.1 Te t cond itons

a) Car y out the test on six cores instaled in a

manifold in ac ord ance with Fig ure 1

b) Tig hten the cores to the minimum torq ue

specified in4.3

c) The test pres ure is20 kPa to38 0kPa

4.4.1.2 Per for ma nc r equir ement

The core leak-rate shal not be g reater than the

v lue set in4.2 throug hout the pres ure rang e

Checks shal be ma e at least at the minimum and

ma imum pres ures

4.4.2 Washout te t

This test simulates ra id d eflation at hig h pres ure

a) Car y out this test on cores which hav e

suc es ful y p s ed the tig htening torq ue

test( 4.4.1)

b) Set the manifold pres ure to38 0kPa

c) Car y out10 test cy cles, d efined as fol ows, on

each v alv e core:

1) open each core man aly and ke p it open for

at least3s to alow the pres uriz d air to

es a e at hig h spe d ac os the v alv e seal;

2) al ow the core to close f e ly

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The leak-rate, measured after10 cy cles, shal not be

g reater than the v alue specified in4.2

4.4.3 B lowout te t

This test simulates ra id inflation at hig h pres ure

a) Car y out this test on the cores that hav e

p s ed the tig htening torq ue test( 4.4.1) and the

washout test (4.4.2)

b) Car y out10 test cy cles, d efined as fol ows, on

each v alv e core:

1) reduce the manifold pres ure to0kPa;

2) at ach a stand rd con ector to a38 0kPa

compres ed air sy stem;

3) ke p each core open for at least3s to al ow

the pres uriz d external air to enter the

manifold at hig h spe d ac os the v alv e seal;

4) after3s, remov e the inflation con ector and

let the core close f e ly

The leak-rate, measured after10 cy cles, shal not be

g reater than the v alue specified in4.2

4.4.4 Pre surized puls t est

a) Car y out this test on six new cores instaled in

a manifold in ac ord nce with Fig ure 1

b) Car y out the pulse tests on the v alv e cores in

ac ord nce with Ta le 1

Throug hout the test, the leak-rate shal not be

g reater than the v alue set in4.2 It shal be noted

after ev ery10 0 cycles

4.4.5 Envir nment al te t at low temperature

4.4.5.1 Te t cond it ons

a) Car y out this test on six new cores instaled in

a test manifold in ac ord nce with Fig ure 1

b) Hold the cores at a temperature of–5 °C

for24h

c) Check the airtig htnes in acetone or alcohol

co led to–5 °C, with air co led to–5 °C at a

pres ure of38 0kPa

d) After co l ng , check the airtig htnes at each of

the folowing stag es, in the order ind icated:

1) at38 0kPa; if the core leaks, retig hten to

the ma imum torq ue d efined in4.3;

2) washout test( 4.4.2);

3) blowout test(4.4.3);

4) at20 kPa;

5) at620kPa;

6) at1 3 0kPa;

7) at38 0kPa

Per orm sev en test cy cles at each pres ure

Fig ure 1 — Manifold

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Ta le 1

Under each test condition, the leak-rate shal not be

g reater than the v alue set in4.2

4.4.6 Envir nment al t est at const ant high

temperat ure

a) Car y out this test on the same cores as p s ed

the low-temperature test(4.4.5)

b) Place them in an ov en and inc ease the

temperature to+9 °C Hold this for24h

c) Co l the samples to+52°C and check the

airtig htnes in water at+52 °C with air

at+52°C at a pres ure of38 0kPa

d) Then fol ow the test procedure in4.4.5.1 d)

4.4.7 Envir nmental te t at peak temperature

a) Car y out this test on the same cores as p s ed

the low-temperature test(4.4.5) and constant

hig h-temperature test (4.4.6)

b) Place them in an ov en and inc ease the

temperature to+1 0°C Hold this for20min

c) Co l the samples to+52°C and check the

airtig htnes in water at+52 °C with air

at+52°C at a pres ure of38 0kPa

d) Then fol ow the test proced ure

in4.4.5.1 d),10times

5 Tyre valve caps

5.1 Test ty es

Air raft ty re v alv e ca s shal be submit ed to the

fol owing tests:

a) determination of mechanical properties of seal

material( 5.3.1);

b) temperature resistance test(5.3.2);

c) ag eing test(5.3.3);

d) s rewing /uns rewing test(5.3.4)

5.2 Minim um airtig htnes requirem ent

No leakag e is ac epta le during the v arious

airtig htnes checks Leaking ca s shal be rejected

5.3 Test m etho s

5.3.1 Me hanical pr pert ie o gasket

materials

a) Determine the folowing initial properties of

the g asket material as ind icated:

— breaking streng th, in ac ord nce with

ISO3 ;

— elong ation in ac ord nce with ISO3 ;

— hard nes in ac ord ance with ISO4 or

ISO8 8;

— compres ion set in ac ord nce with

ISO815

b) Determine the properties of the seal ag ain

after ov en-ag eing at+9 °C for7 d ay s

5.3.1.2 Per for ma nc r equir ements

Variations in tensie streng th, elong ation and

hard nes characteristic determined after

ov en-heating shal not difer fom initial

characteristic b more than the ma imum

v ariation v alues g iv en in Ta le 2

Ta le 2

5.3.2 Temperature re istanc te t

a) Car y out this test on six v alv e ca s

b) The serv ice temperature rang e is–5 °C

to+9 °C with a24-h hold ing period at each of

these two temperatures

Ope ation

Pr s ur

kPa

Cycles pe m in te

Total cycle in this

condition

min

a

ma

a

Ne er let the pres ure fal b low the in icated minimum pres ures

Characte is ic

Inc ease

ma

De r ase

ma

( to be specified)

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c) The ca tig htening torq ue is betwe n0,5 N·m

and0,7 N·m

d ) The test pres ure is up to38 0kPa

The requirement in5.2 shal be met within the

temperature and torq ue tig htening rang e for

pres ures of up to38 0kPa

5.3.3 Ageing t est

a) Car y out this test on six v alv e ca s

b) Place the ca s in an ov en and inc ease the

temperature to+9 °C Hold this for7 d y s

After ov en heating , the requirement in5.2 shal be

met

5.3.4 Screwing/uns rewing te t

a) Car y out this test on thre new ca s an thre

ca s ag ed in ac ord ance with5.3.3

b) Sc ew the ca s down with a torque

of0,5 N·m10 times, u s rewing them each

time, ensuring that the seals break contact with

the v alv e mouth

Car y out at least fiv e of the

s rewing /uns rewing cy cles at–5 °C on ca s

which hav e be n held at this temperature for a

minimum of72 h The ca s shal not be s rewed

onto the v alv e bod during this72-h hold period

at–5 °C

c) Sc ew the ca s which hav e u d erg one10

s rewing / uns rewing cy cles b ck onto the v alv e

bod an torque them to betwe n0,5 N·m

and0,7 N·m

d ) Apply a pres ure of7 kPa and hold it for1 h

e) Apply a pres ure of38 0kPa an hold it

for1h

f) W ith the ca s sti tig htened onto the v alv e

bod with the same torq ue, co l them to–5 °C

and hold this temperature for24h, a ply ing an

internal pres ure to the ca of at least38 0kPa

The requirement in5.2 shal be met during

stag es5.3.4.1d),5.3.4.1 e) and5.3.4.1 f) In

a d ition, after this test, the seal shal rotate f e ly

within the ca without becoming u seated

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List ofreferences

Se national foreword

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Tiêu đề	Test Methods For Aircraft Inner Tube And Tubeless Tyre Valves — Cores And Caps
Trường học	British Standards Institution
Chuyên ngành	Aerospace Engineering
Thể loại	Standard
Năm xuất bản	1995
Thành phố	London

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