L

i. Imp<'trta,nce of lvLuid Lines in ,4ircraft:

l.s aircrafc become rnore versat,i le and more effec-tive, lhey alsio becorne rnore sophis;ticaLed. Manyof to<lay's airpla:nes have hydrauiic la:nding 5;eartl:al ;:equire [housands of pou:rds of iorce tc re-tract. They have boc,sterl f l ight controis requiringhydr:Luiic fluid unde,r high nressure to be car:iedihroughcul .bhe airr:rafL, and the fuel syst{tmsthrough'whi<,h the huge quantit ies of fuei f lors tothe engirres erre built; up of ,3om.ple,.< iines, val'res,and fitt irrgs

T'he p,lunrbing used L,o carrl' thr: vil;al fluid.s rriustbe stron55, asi some r:f the fluids are under a nor-nral pressure of up to 3,Ct00 psi and have transi.enrpressure sur{les rising firr above this. These hnes

ltig. i7-1 Mc,dern ai.rcro,ft d.epend ,tn both.

f,tuid:;, so'me of which are under pressures

Fluid Lines f,nd Fittings

must be l ight in weil3hr and must user fit; ings that,prodtrce a rn.inirnunr drop in the presrsure of theifirrid flovring; through l;hem. F,rovision:; mrrst brrmade by lhe use of flodble hose lor relal:irre rrro-tir)n becween lhe airfrarne ancl such r;hock-mounted cornponerfts a.s the engines ancL t;hr: in-struntent pa.nels.

Il'. )7igid Fluici Lines

A. Materials

M,an1' of the fluid li::es used in ear.ly airr:rafl werermade of copper tubing;ucl the'J.ihration ern-cl gI,".

"t gAg$-ruglrldjia r de!-qb-S-SlX gi"?F,

c;1gg9it.!91-J"v*.q-q3ll"i?"9.-and9_v,p;:tga,!ly*,Qt-gi$,'t.,prevent this; happening, bhese iines were pr:r-

'1r l * - i t ; , * l l ,nur l 5, f Vt>1 t?+. j . t5\ * t , ( - ' ,v , - , i ' - ;d:

Fu-i/ tj..* - ,Lgr* ; {)f. q' u,.* p!,"a17, 1t ̂ L

L'i1,cl 1..*,r -

t ,2YD ?,ro ?5. .

l)ra'cl^-. -. : 1t4t-, ,-..- -,-

ig'id and flexibler fluid line:: to carry I'ue\ oil an,l.of thousands 'cf pou'n.ds per square incit

, r . \ .

/

,i

FLUID L INES AND FITTINGS

PAGE o2

CH^P: L/C. PLUMBING

iodically removed from the aircraft, heaced reQ-f,ot *liir a twould sollqn the copper so that it could be usedagain.

Aluminum alioy and stainless steel have almostcompleleil ' replaced copper for use in aircrafL.{rcwpressurel stste"frig. such as instrument air orventilating air are often made of commercially

' : \ , ' r '" -pure-'aluminum (ii00-H14-half-hard); or aiumi-

nu m*having,a - small" percentage . of man ganese,3OO3.iFI4? Fuel and engine lubricating systems

-lL.and hydraulic or.pneumatic systems that operate:";' in the i,000 to 1,500 psi range often use iines

madb of :5052-0.aluminum'. This al]gJ! Jyg-0, or annealed, sLale is about one and three-quE-rters times as strong as the iommercially---_____---:_pure aluminum in its partially hardened condi-tion.-

. { 1I - )

\1^,<

}OccasionaLly 202a-T aluminum ailoy is used for: fluid iines because of its higher strength, but it is

*o:.5$ligdlto blend and flare without cracking,and more care is required when it is used;tr..)

, ' t ' /

- Stainless sreel is often used for high-pressurehydrarilic and pneumatic lines and for iines carry-ing high-pressure oxygen.

Most of Lhe cricical fluid lines in our modern air-craft are fabricated at the faclory and have all of

, the neiessary bends made and ali of the properend-fittings installed. These lines are specifiedand identified by their part number. It is extreme-lf important, when replacipg a fluid line, to"useonly a line having the same part number. as thatoriginally installed. If a line must be made up inthe shop, lhe aircraft manufacturer can provideinformaLion regarding the material of which theline is made. Aircraft tubine is normaliv iden-tifi"d *ith the ydesignarion srapped on rhe o-u-ts_ide gJJ!g!gbj$.

C D ' i ) t A t r t C h Y t tE. Size Designat ion :

' \ "

' j , ' ' , -_ \ _ . r b : L x r L

j4'

. 1 ^ * t

Rigid tubing is identif ied not only by its maierialbut also by ir..s size.

The outside diameler of the tube is spe,cified in in-crements oT 1/16 inch. All of the fitt ings thaiareused, forexample, @

The wall thickness of the tube debermines itss[rength, and to find the inside diameler of thetube, twice the wali thickness musi be subtractedfrom the outside diameter.

Pig. 3-2 The outside diameter of rigid tubing isidentified by its dash number. The dash numberis the numerator of the fractionaL diameter in sir-teenths of an inch.

UI. Fabricating Rigid Tubing j

A. Cutting

After the correel length of tubing is defermined,it shouid be cut off square with a roller-type tub-ing cutter, such as the one in Fig. 3-3. This type ofculter supports the tube on hardened sLeel roilers,while-a gharp sieel cutting wheel is screwed downagainst lhe tube. The cutter is rocaLed around thetube, and as the biade culs into the metal, it isturned down further into the lube. This type ofcu[ter produces a cutoff that is smooth andsquare, but it does leave burrs inside of the tube.These burrs must be completely removed withthe reamer blade on the cutter, or with a specialreamer such as the one seen in Fig. 3-a. T_gglg g!Lhe tu-b-g mus*t be-p:lir@go

:Btp$g^".f *he!-..-e*u-i"d--pdsse-:Ees-sslsentlg-t ions which would cause cracks when the tube is

If no tubing cutter is available. a fine-toothhacksaw can be used. Be sure to use a bladewhose teeLh are fine enough that at least twoteeth will be on each wall of the tube at all times.

TUBEo.D.

1 / 8

1 1 4 -

3/8

1 t2

5/8

3t4

FITTINGSDASH NO.

2

.- 4-**)

6a

8

_ 1 0

- 1 2

- 1 6

ter-inch outside dia

^,--

t

o

$l NepatffiAiriines

9 a

FLUID L INES; A I | tD F ITTIN13S

tl

P,A,GE: O',

cr-rAP: A/C. PLUji l i1NG

B. )3en,Cin1J

The tubing use'J for.aircr;rft f luicL i ines; has ,qtritethin walis and wil l collaFse in the bernd if ade-quahl precautions are not laken. .Fig. 3-5A s!6rwsa piece of tubing tirat r,r'asr be:nt rLsin,g nr) j)recau-tions, arrd the resulting bend is severerll ' kinkecl,restricting the l lov'of.an1' f luid throrrgh the l ine.The Lube in B is wrinl: led an<i, while rrol restri<:-ting r"he flovz so bacily':ts a kink, s'rjnl*i'as n,iit sti.[causo an opnositioll and wil l severely vrealie:n lhetribe in t;he'xnd.-

In vi,:w (l we ser: the tube as it apprears a.f ber beingsr:ccessf ully bent, The be,nd should be -gm,:o_tfL,with no marks from the )rendin6; r;ools, anci ;herrrinor ciiamerrer in the trenci sh,:ulclltFTdE;s ciran757o of the rl$;ggpr o.f th"=_tUbe.

'---'

Fig. 3-3 Rt>Ller-tytrte t;.LbirLg cutter u,sed for cut-t:ing small dia;met'er rigicL ttt.bin,g. tl hardeneclsteel reamer is 'zttache,C to thet ba':h of the aLtterto remoue tJrc burr:: tha.t t lds t:ype of c:utter t 'zndsro le'zue on the inside ctf tlr.e tube.

)"ig. 3-4 SpecicLl tttpe of reo.mer t'\at can renrout?lturr:; frctm ttoth. the in:;ide ancl the outsiale o,' thee,nd of a piece <>f tubing. On.e side of the rec!.me,.c:Lean.s the outs,ide cf the c'ut. anci the' ot,her sideclean.s the inside.

i.emove all of theilared

Ftg. i l-1 A -- BLinhed tubtng, cau:s,zd t 'y nvakingthe bend wi thout u: ; ingany bemding tooLs. B - -

A wrinh.Lied bend, c'aused by rcir,.g a.n i;'n,orooe,"be'nding too,l.. (: -- A proler ben,l.. 1"he rr,. iro:diam<:ter in t 'he bend must be no less ,lhan ',75€;c

ofthe original ,Jiarneter o,f the tube.

Froduct;.on bending is done by the ulsr: , lf a cr:bebender simiiar to lhe one seen in F isr. 3-6. lthetu6el!1la-mpert b.,t*r=" th";;*;lLJ, ii"a u

---diamp bar, and thr: radius biockjs trlrned bv a

r '--

gear Friven by ther handle.(F.s lhe ;Ediuribl,rcktrrnrri-tlrrruttdis-bent te#a" r;h i6Ailil5i;k\+€<-i---=i-.-' --r r '^-^etu^v-ano ar guroe oar. lne nt. lmtrer c' I oogr€e{; ()I o€lnrl ls

ael&ff\r1.the: an:ount t;he radius blech isturned.l'Ihin-wall tubing is kr:p[ fforn gqllApgllrB

by_",i4[_g_Fe4drel; which is a smoot;h rr:unrJ-r:ndE* th"C fits into ttil tube at the proint Lhe bend isbeing; formed. It holds, the tube r;o it cannob col-Ierpse.

HHF NepatGAlr,tnes

cHAP: A/e - PT,UI:3I i {G. . t v .

FLUID L INES AND FI f i INGS

L . 6 . v v

can,/r'

t '/,

i6mall-diameter tubing may be bent without col- /rt-

f"rr*- U" usins a huia Ue"aing rool, Such as rhe ' beTent 6y_bg"la, Llgg-g,tfg!Ltly--Y^99-1q-9!q9! 99lloi" *iig. "

ti "

qpF;g tFqi-llCJ snugl:l around the cu!ilS-!3-\e-elIapsing by using a hand bending too-], Such as lhe

' be bentty b:"1$ Ls-r+g-gi

FTtr;tip. me shdJEaThandie can then be mov'

-a-Aowffi bend the tubing ro any angie that is

needed. The number of degrees of bend is read on

the scale f f i oPPosite 'rhe in '

cidence mark on the shde bar.hnt that every particle of sand is removed from

the tube before it is inslalled in the aircraft.

A variaiion of the sand method is used in some

factories for making very complex be,,4t-14,!ub--j.g. The ube ii f i l led with an extremely ioy-*itine-Fointil.tul

"rloi Juch as woodtt metal

ot Ce..-o-lle"ci. Thete iitor;; are melled in boiling-__..--.-:,water, unO tind is bent. When t@com'.-6lered. the tube i5 placed in a vat of boiling water,^#

eEjbr-lltoY mells and runs out of i!'

C Methods of Joining Rigi-d. Tubing

1. Flared fittings

Much of the rigid tubing used in modern aircraft

ls lo lneo, or ls conFig.3-7 A hand-type tube bender that is used for

tubin

A production-type tube bender

;a tlren m;lins ,he bends.

o

o

I

I

FLLIID LINES AN.D FITTNGS "

.tl

$l Nepal#f ll.irjines

1 - F :A ISE SLIDE-BAR UP' /YAl iD .

S L I D E : - B A R

I N C I D E N C ; E*o *a-"

2 . P I . . A C E T U B I N G . I NB L O C

T U B r i N G

)

\:JL

R A D I U SBLOCr [

--rr \- C L I P

3 . P R E P A R E T O R A I S E C L I F )O\ /ER TU BI l . lG .

, 1 . D R O P C L I P O V E R T U B I N G .

I N C I D E N C E M A R Kli lAFiK ON RADlUl i

C O I N C I D E Sa I r \ a . r

WITH ZERO

$ - B E N D T U B I N G T O D E : S I R E D A t \ l G L E .

90 DE:GREE M,ARK

6 . REMOVE BEI .TT TUBINC i BY ' L IFT IT ' IG ISL IDE.BAFI A I , ID RAIS ING CL IP .

A B E N D O FAS SI{O\ryN

9 0 D E G R E E S D O N EIN ,ABOVE STEPS

Fig. 33 Usi;ng ct ltand-Jield tuL,i bender

-

l- -c3-o. -. - t;epalE,ilnrnes

FLUID L INES AND FITTINGS

PAGE: Q$

CHAP: A/C. PL' 'JMBING

4pcve{ d*J= 3V'

'4t)->,nz\arz h?' 4S'

l,_L ̂e .;,,n1_,v )

t, / ...--*

,33" ,..--*

. . i\ 1

i

T O E O F' . 1

SLEEVE,r

\

M I N I I !

(A)

/-

o[JTslDl<- oF1

(B) at t r t rvF

M A X T M U M F L A R E

Fie. 3-9 A - Aircraft igid.tubing is.flared witlt o flare angLe of 37: E

flaring the end of ihe tube and using flare'tvpe fit- fi:tlittl;f?'

t ings' soiidiY against the

Automotive fi l t ings have a 45-degree flare angle' - '2he B-nut is t ight'e

and to prevenl t"t"ft and automotive fitt ingt V"::,^:,nut

never

being used i, lt".. i tu' lgtubiy' ai 'c'aft f i tt ings have t

against the fitr ing

a 3?-degree flare angle' ihe aircraft can ca'

The actual sealing is done by rh3 :p91i1t between There are two typ

-- of aircrafl r igid tubi:

;U*i"i". ,yLi.j_{$?_p"ihe fitting. 'I 'hese c - - -. -;;;;J";,

.*tereTfi4'o*q@ 4 _ o c r _ a c k s , s@uase' ffiBefore the tube is llared, a B'nu! arrd. sieeue are 'r/

slipped over rhe "ri,@ 4!*:

there is a

ronn a na.e *l,osg ?ur.qde Lrp?Let.iq-lf"tT t^nf,":1"*t"-ot*"

that of the insrdegflb@,L-tAg

, ...--1,33" .-?l

// 37" I

{,/ Iqr"l ' '

rL,J

l \ ' :

f tV . i )" t . t /

U M F L A R E

/ . ,, i , : i' \ /

/'L i

=T;;;BSLEEVE

- I n e t u o g m u s l u e l L U t Y u r o-ffi.

leeue. but is no larger tnan tu

' L s' d e-dtg!1919l- e-f -t! e sl ggv*e'

iormed so thac the flare rests

flare cone of the fitt ing before

ned. It is extremelY imPorlant

be used Lo Pull the cube uP

, as v ibra i ion or expansion o l

rse che tube to fail at Lhe flay

es of nuts used for connecting

rg Lo the f i t t ings. The AN8l l

,ce nut that can be used onil%is s t ratght lor a otst . ";u tTa n Eil]ltp€l-back al on 1

end is being flared.

bend near the end of the lube

nut cannoL be used and th

the MS20819 s leeve mus! b

a.

P-* P ") ,)

o

o

WU NepatWAiriines

F L U I D L I N E I S R N O F I T t l N G S ,

I

PACiE: f)]

cHAP: A/ C ,, PLU[i]3:1\;G

The Lorqtre valur:s shovrn in F:lg. l l- i1 : ihcu:lcl beus,:d rvhen tighL,:nirrg the nuts 6n a flared tube.O'"'ertightening c:an forc:e lhe sr.eeve into t,hr: t;ub-ing and damage i l . causing i t to ieak.

^ Q ; . , - r ^ f | ^ - ^a L t e 6 L . l L u ,

(

A rqin;;le flare may tre formed on a_p'iece <>f rigj-dlut4ng wit;h either an irnpact-tyBe_llerriajg-leol. orone havin:z the ro l i ine a: t ion o l thr : i lc . r in : r , :one.

FiE1. 3-i2 :;ho',rrs an iFnpacl-t;ype flarin6; r:ool. Th.etutre is; cul off square and its ends; zrrr: oc'l isherl,and it is cian:,pec between t,he .nalvers ,:f lhe viseblocks wilh oniy abor:t l/16 inch of the tube srich-ing up above the blocks The blocks are clampedin a vir;e, and ihe pin-type flarin;g tool is; clrivt:n in-to :he Lube wi bh its f,:q'r;harp bio*'rs <tf a hamrne'ras i lre:reeded to flare the tube enC oul, a.gainsc chebevei cut in tbe blocks. L: is jmp,crte,nll;bat_asj-ew

blows as pos:;ible be$$,J- as rnanv Iignt b,lc'wswi l l work- . rarden the tut r rngT

1 / 1 6 "

L-^\

i-t

Fig. 3-.12 An impacr-type fiaing tool

Ro).l ing-tyce flar:.ng tools are quite popuiar i:navialion rnaintenilncr: shops because bhey are er,-t ire:ly self.:on.-ained and it is easy,t<t rnake a goo'lf lare with this type ,rf t 'coi. The tool pricturr:d i:r_Fig. 3- t3 q,ill llaie tubiru11ryfitr-tqi|Efi-qE;

#-stdl diameler. T'o use thir; lool. t,,ne dies ;lre

- # - ' . .

rotateci urrbil Lhe bw,c halves oi the cor::ect sizehoie a.e aligned and the tutre is inserted against

used. The hole in tfris nut is large enough lo sliprover bhe tai] of the s;Ieeve, ernd so ir can easily sliprzrrou:nd the bends in i:he tuLrina. The nu[ ands;leeve are s]lpgred ql&r th-e- tudre]2 ;-e-Jl i.'f lare,l, a:rd vrhen the conner:tion is assr:mb,led. thelnut loro:s tire sleeve against r:he bube to form at,ight seal beLween the flare of the tube and therf lare cone of thrr f i r , : ine.

A N I 3 1 7 N U T

U >.)

I,c*'-*,o^SLEEVE

lt u) lw

Tube Q .D .( inchers)

3/1 6l l t l

5 /1 63/tI1 tll5/t!3ltI

1 .l ' t l . l

1.1 l1'-

Wrench torrque rangefor t ighteninr3 tube nuts

( inch pouncs)

Alum. a l l c ,y1 1 00.H'1 4,

5052-0S;leel

40-6560-80

75-1251 50-250, 4 U U - J J U

1300-500500-700600.900'500-900

130-70jt0-90

70-12090 .150

155 -250300-400430.575550-750

Ftg. 3-1 I l lecc,mm.ended tot-quc ualu,zsti,ghterzi.n,g tube nut.s on air<:raf,l riErid t:ubing

Fig. il-10 A - The AN8li' nut is o singrl.e-oiecen,ut and. can t,e ".sdffi6i6@e *"*hends

---:'i--rtear the,znd of t lte tubing. These n:.uts ere not: asffiTcctor\,1;Tile n'tt aVd. sleet,e cttmbinaii ion, astJtey r.enctto wipe, o," iron, the flaret as it i :; beingt ighte,neal . I l : - i 'he A)Y81,8 nut wi th thelv[S2ABrc sb,rui is i lre rnost p"'p"1", tvnr$@'*_----fc,und

91 ,ldq tr!fu*fTese ntEare -on;mo{l----;--c&Ltea b-nu ts .

fuj't ,1r*ul^I-

(B )

for

Eg Nepalffunrnes

D i m e n s i o n sT u b i n g

T u b e S i z e

O u t s i d eD i a m e t e r

I I nch l

3-13 A rolLing'tYPe fLaring tool

/. 1B '

Fo r S ing le -F la redT u b e S i z e

Fig. 3-14 Dimensional toleronces for a singIc

bhe stop. The dies are clamped iogether and lhe

flaring cone fs [urned into the end of the lube.

Roi lers in the cone burnish the metal as i t is ex '

panded into Lhe ciie, and a smooth flare results.

\4rhen the flare is formed sufficiently, rhe handie

is reversed and the d ies re leased, and the cube can

be removed from the tool.

F ig- 3- i4 is a char t of the d imensional to ierances

useci for forming a single flare in both aluminum

al lo l ' and steel fubing.

b. Dou bIe-f\are

SofL a luminum tubing having an ouLside d ia-

meter of 3 i8 inch or smal ler may be double- f lared

Lo pror{d67?Lronger connection to lhe firt ing'

To double-flare a piece of tubing, cuL it off in the

same lvay as was done for a single flare' remove

all of the burrs. and poiish fhe end to minimize

the possib i i i tv of cracks. Inserb the tubing in to

lhe i ianng die ro the depth allowed b1' Lhe stop

nin : r rd f .hen c jamn the d ies. lnser t the upseLr, tngp l I r q r r v v , ^ v r r v ^ s - ^ ^ r

iooi into the die and with as felr ' biou's of lhe ham'

mer as possib le. upsel the lubing ' Then inser t Lhe

flaring iool and strike it with fhe hammer ro foid

the metal down into lhe tubing and form the

double- f lare.

cHAP: A i i . FL IT I ' :3 . I l l3

F L U I D L I N E S A N D F T T T I N G S

lt zl

.a/

MS33584

S l e e i o r

A l u m i n u m A l l o v

T u b i n g l l n c h l

BBac i i us- . 0 . 010

l l nch l

0.200

0 .302

n 1 q Q

o 421

0 4 8 4

+ 0.00C- 0 .01c

+ 0 .000- 0 ,010

+ 0.000- 0 . 0 1 0

* 0.00c- 0 .010

+ 0.000- 0 .01 0

* 0.000- 0 .010

+ 0.000- 0 0 1 0

+ 0.000- 0 . 0 1 0

+ 0.000- 0 .015

0.0 32

0 .032

0 .032

0 .03 2

u . o J o

0 . 7 8 1

0.937

0.046

0 .062

0.078

, 0 . 0 9 3 P' ig. '3 '15 A - Inscr t t l rc tube to the st 'op p in and

clamp the d ies together . B - Inser l the upset '

t ing tooL and st r i lze i t rL ; i th a hammer to upset the

eni of the tube. C - Insert the fLarin;4 conc and

strihe it with the ltammer to form the flare't i s i d t ub in

a

e

WF NepalwA.inines

FLIJID LII ' {ES AIID FITI ' INGS

PriGE: O!

^ f ' r - ' l r r i r ? r - ' - ^

cHAP: ; r , t l ' , -YL ' j : . i : r l . - i t r

T .

B --+

l ll i

penrls on the s:ze of lhe tubing and t.his should bedone accorrj in5; to lhe manufacturer's r,3cornrn€rn-dations.

I'ry ----F- ____l

| -il Fl--*" II t ; i l Fl I

i \il il_FERR'r'.E IlLlr Itf-nti l-=

-,n PRESETTTNG I

I L--i Ii re r . : HOLD wr rH FTNGERS I| [ ro pnevEN-i Ro-ArtcruiI Ar'h

Ils tll/ IT"( il,It'r I

| ,r'i---., i| /i ; -rJ,u*o,,o,*,ji i( @;=*:-=-- ;I \t -/->=::; IL):==1:--- lFig'. 3-17A- In.stoll the n;zt a.nd. fe.rrutde o;z !: ,encl of the tutting. lJ - Seat t,he e,nC ol the t:ing firmly agtin:;t tt\e bottcm of t:he pre.sett,i.:.tool. 'C =. Turn ,the nut d.oun u.ntil ,.esi.st.znce. i:.ielt, and tlrcn turn it l-Sl4 turn th:. is r,oi n'

Tube SizeNomina lOu ts i deD iame te r

I in. l

Diarmetgr+ 0 .010- 0 .010

l t n .

Rad ius+ 0 .010

l i n .

r f fa l l

Th iekne: ;s

l in .

M in i rn u m

l n s i d el f iameter

I in . ]

1 /8

3/1 6

1 t 4

ti/1 6

ri/8

I ^ ^ . ' ^u . . 2 1 | u . u J z

0.302 I

0.032

I0.3ss I

0.032

0.121 I

0.032

0.484 I o.o+o

Cr.028c).035Cr.028Cr-035c,.035cr.049c,.028c,.035C'.049

0 - 1 1 40 . r D 00.1 t80.1r590.2:240.1!180 .3100.21180.2t i l

7is'. 3-'t 6 rl.are on a trt

l. FLareles

t is dil'ficu.' o n r r i r o d f r , t,::-Yl:*-:,:::, i . , - . . f r h r . ,r r r ! ? a q r w 1 r J '

he "bi te-t1n-aor tfiesi

lub off bhelf Lhe br.rrrrnd ferruleru1. ont;o bl'tJe sure bhe,he, boo[, arr,i l i t f i o h f o

rsing a wre,hrqg:gggl

)imen:;ional tole'.ecet of airc'rafl ri;

s fil.ttir.Lgs

.t to flare the tLear' some-o f r : he h f .lraulic anC pneu

?e_'' f lr lrei,:ss fittl arrplicatittns.

encl of the lube scs and pol ish i ts toverr ofre end of the presetting t,rol,tube is square ai

I then screu ' the rns the ferrule agnch, turn the nute* of

" t,fr'.TT

'ances for o al.ouL,le'id t:ub[ng

v * glL.u b-i q &t,h-a !-I,sa o r n r p ' l q r r r e l i n e q i n

mat,ic i;ystems;, and.ng has been desi$r.

uare, and remove allrnd. Then s;l ip a nute tube and scrt:w theas seen in F ig. 3-1.7

Sain.sf the bott,om olrit ciow:n by hand un'ainst the l,)ol. No\ry,from one to orte and

le exacr" amounl (le

"ll tlE?dtr Nepal I FLUID L'NES AND FrrrrNGS IWf i i r l i nac r ,

I .. n o. !-,/ J . pLLrl'iB IliGl t " "^ 'I

amine the ferruie. The Lube should have a uniform | . ii nc ien t .a t ion conrp ie t -e l1 'a round i t s end, ind icaL ing I Ichar rhe tu i .e i s square and has bo t tomed even ly I

t , , I

in the too l . ' fhe b i re shou ld be even. and rhe I I '

Imarer ia l shou ld be ra ised ro a he ighr - o f a r leas t I t I50io of lhe rhickness of rhe ferruie leading edge. i r J i lL IThe ferruie mav be ioose enough thar i t . can be I

' l l i l l ] I

ro la ' -ed on :he tube ' bu t i t shou ld no t be f ree | 1 - - - . , l .1 . - f Ienough LC move back and forrh' RoLalg-lbe--l9l I ; dl,', l i ] Iruie to see rhat Lhe L'Lqrelqqi- ls s lrqighr ' u ' i rhrhs I F\ le I I- t r n d - d - r h e - l e - f f T f t i n d i c a r i n g t h a t i r \ \ ' a s p e r ' | : I l l | i I I

i io-[n"-rub"]U-fsruissngg:A I j \' l ]-j Ibe st,gflfi1*q9yed_-!9 provide rhe proper seqltlg

| ) i ; L_.. Ifeut t ts tJheedgeofrhel icr " i lg . I I i i I I

I 'll l- II ' l i i ! Iillliliritlti

8 . . c ( i r 1 1 , . , i ; ) ' . t , ' - ' e . ! | I

I - I

I n. \ '\

rn : '

I I | 3' II r\!s\_ II - |

i t f f i | , ' u . ' . ' n A p r o p e r l 1 , c o n n e c t e d f L a r e L e s s t u b e f i t . .i

'.-l I t;ng

i - i-t---T-tEII-- Ii I I I lElll I 3' Beading and hose ctamps: : t r t l t t - i

| . . _ \ - . - - ]

lH f | ' ^ - - ^ - r i i amoro r l i nes ez r r v i no s r r ch l ow -n ressu - ^t \uJ , I Large-ciiameLer i ines carrying such low-pressul tr

i . . . I nu ia. as engine re lurn o i l and cooi ing a i r ma1'be

| -Af l ioined *it it a rubber hose slipped over the ends of

i I I in";uua-a;d held in place with soew-rype hose

i I cla.,,ps'

Fig. ,3-18 The end of the tube shouLd haue a Before s l ipp ing the hose over the end of the tube'

uniform inclentatton all around' it, nnJ fi l 1119 l1:...t:0" musL be beaded by'using either a power

hi tp of the rube shot i ld ra ise mate( iot appi l ' beader g. " l i id .

beading tool ' such as the one

, n;f',-fi{, q:ren>rnt: :f inUL'-tn seen in Fig' 3-204 -- ' -: -' / '\

t:ffii-ferruLe shiuLd be sLighttt' ' 'L -- ?

bou,ecJ (C). v L ' 'e te ' - - " - -o

Af ter the hose is s l ipped over the beads, cenLer

Lhe hose clamps beLween the ends of the hose and

The rubing musl be rouLed and posi t ioned lo res l the beads. T ighten the c lamps f inge' - t ight and

agarnst Lhe firring so Lhat the.,ut g'i l l not have Lo then one and one-hal!!?rlYv-q::+I^e:?+:Ll: I iqn

p, . , t t u t . , . I ine inro p lace. Be sure thar the f i r t ing is a wrench or a pai r of p l iers. T ishrentng Lhe hose

per fec | l yc ]ean 'andScreu ,Lhenu tdownunL i } you jEgE: -g9= !g ! i *? l i , - . 3 } ' .@fee l res is lance. Noq, , us ing a u, rench, l ighten Lhe hose. This is a condi l ion in which. .qhe ruboe.r . ]s

nut an ac id i r . ionai l /6 Lo 1R rurn. Neucr t ighten o sqqeezed so. l ight that iL iqscs. iL res i l ience, , and ILS

fiareLess i itt ing more than J/3 turn after re- =4ffi+g"ell i i"-arE impaired'

s isLance is t 'eLt . i f rhe f i r t ing leaks, d isassemble i l ,

and check Lo be sure that Lhe tube has been pro. IV- Flexible Fluid Lines

pe r l y p re fo rmed ; t hen recoup ie i t and p rope r l y L - ! - - - _ . r ^ - - , -

P A G E : 1 C

iigtt"n t.he nut. If i t conLinues lo leak, rhe end of When there is relative molion between the com-

the fube wil l have to be cul off and a new ferrule ponenls that are joined by a fluid l ine, a flexible

nreformed onlo the tube. hose must be used'

E-dF NepalffiAiriines

I

I

FLLI ID L INES AND FITT.LNG'S ,\g4 NepalAirlines

II

(A)

D0)___--___: \l \ v ' ! vaa

_ 1 i . , - , . ,

h [ . ' r ' r -

}i ' i:sr cLAMP( \., ..'1

Fi5y. 3-1)0 A -- Hand type tLtbe beadin6' tool. E -- The encis of the tube are b'zaded L,efo,"e t,\e h:.o:;e issLi: 'tps(i ouer tlLem. C' - Thet hose clamps ore ient:ered between ;:he end of the hose and thet ltezcl..

A. FLexibLe Llose Const'uction

1. Inner L iner

The inner t.ube, or the i inr:r, of a :l lexible hose c:u-riei; lhe fluiC, and il musL have a min.i.mu.m poro,si-ty' and musL tre chenrically- compati.bie with t.cemater ia i being cai - r ied. I t musl be smooth so thatit '^/i l i offer r,fLe nrinirnurr resi5f.snss, or oppo,;i-Lion, t,o 1.he flow, and it must be fl:xit, lebhroug,rou: the entire r€rngo of operating tern-peraLures iL wj l l encount€,r .

There are basical ly four c l i f fe : renl synthet ic com-norrnds rrs,:d for t.he inner l iner of rarrcraff f luidi ines. I r ieoEren,s is a form , r f s /nLhel ic rubber chalhar; a soof=i6ais',.ahce ii j 'ai i.usio.r and can beuse,d f r i r rnanv f l u id I ine appl icat ions br : t i ts-resi_ii_?irti: f.o-iiijlroleum-base,l oils is nol as good,i l so*e of the oc i rer <:ompounds.

lBuna-ftr has a bett,er resisiLance lo petro;.euro pro-

_{_-ur;!s".tfr-an_q99!59.Ffi-d'F jisgnlor-qp]ilic{iii6,rsin which qetroleurr-r fluicis; are carrierl.

' - l trgy-l--is noL slriLable ior r:se wit,h pe,iroleun:r pro-

ciur:tslirur iL rs exc:elldilE3-arinireil i ibl Ior I luroiines cafi iTing pirosphat.e esterbase hydraulicf lu : rds such as.Sk] 'dro i . - 4ul7 I , CC;,o l

Te:flon is a synLl'reLic resirr comp{tun{l bf'DrrPqnI.bhzrt can ber used as an inner tube for f luid Lines. It

has ,an erxtr,:mely vrider usable tempe.raturo range,t :x tending j rom -650 F lo as h igh as +45cro F.'feflr ln's unique wax-Ii.ke sur{'ace has a m-.ninrumopposition 1;o fluid flovs, and i1; has a 'ren i,rr:.g se'r-'r ice i ife if i t is properly used.

:2. )Teirtfor':ement

' lhe sLrr rnst .h of a hose is deci : rminecl i rv [he re in-lorcr:menl ,,,rhich is piaced over the .|nnelr tube.llein.forcementsi ale rnade of co[ton, ravc)n, (fr

poiyestrlr feLbric, or of either cariron-st,er:1 wire ,lrsitainless sceel 'wirer braid.

'fhe design of t;he rein.forcement is cluic: :rit icai,as the irosel has a tendency to increase its dra-rnelor and decr:ease it,s iengt,h \Arhen prer;sure is; rnnl iec i Thp n.nnpr r ies ip 'n of i l - rp r , ' i r r fcrcenre:r t^ ^ ' "

H '

can minimi:ze l.rese di:nen.sior: ch.anE:ers.

.1. t )utzr coue,-

.4. proteclive ol-rter co'r 'er, usuallv m;tcle o;: lal>r..c,rubtrer, or stainless steel br;aid, is put ovrrr Lrereinlorcemenl to prc,lecL lhe hose frorn s;u':hphysical damage as al:rasiion or rscuffing.

)3, Mettsurement of lvLexible Fluid -Lines

'+fhe size of. a rigid fluid linr: is measurecl try it,s or,:t-:; ide diamel;er, but; tbe size of a flrxible l ine iscieberminejd by its inside diameter, rrreilsureri in

, )

Vl Nepat-

^ t r r . . . t E r r

F L U I D L I N E S A N D F I T T I N G S

- t .vnp c

a

- . )A

- 6- 8- 1 0

increments of l i 16 inch, u'irh the dash number re-

ferring to the size of rigid tubing u'ich which Lhe

hose is compatibie. A -10 hose wii l f lou'the same

amount of f luid as a 5/8 inch rigrd tube'

C. Lay Line

Aircrafi f lexibie hose is marked with a yellou',

reci, or u'hite stripe running the length of the

hose. Along ih is l ine is pr in ted the in formar ion

neeoed ro iciencify the hose. The MIL-spec nurn-

bei- of the hose, [he manufacturer's name or svm-

bol. and the year and quarLer of the manufacLure

of the hose are inciuded. as rvell as the dash

numfer represenr ing uhe hose s ize and, in some

cases. lhe manufaciurer 's par t number ' This lay

Iine is not only for idenrif ication of thti hose, buL

it serves to indicaLe whether or noL the l ine was

rrvisteci when it was inslalled. Instalied properll ' .

this i ine wii l run straighr and nqL spiral around

t h e h o s e . i 1 , ' , : t , " - q '. . t s -

M rL.H.879a:SlZd,S'ZlSANl rC sYM BOL

Fig. 3.-22 Lott-Pressure hose

sieel braid to lhe inner tube' Over tl.re sceel braid

reinforcement is usualiy placed a braid of rough

oi i - res is tanL coLLon.

If the hose is to be useci with any of the pecroieum

prcd,ucts, its inner Iiner is made of:v-TffiF

te#firs ouler braid is gra5'-black But, if the

hose is fo be useci *i i i ' 'r W

99:Ph*:::qs:n"!he-!E-hvft auii-c[]s'ds*'r-[e-1n';e r lin er i s m a d e o f s y r-r 1!r-e.i. 118-u !.v-1". t-u!Uqi4 l3-the'

o,iiiiiljiltl i-c; i ";;,q}esr tI e- I a 1' I i ne ha s

the word SKYDHOL o" lt, along wi[h the other

information'

DashSize

Max.Oper .

p s i

600500400300250250

t / P

J / t o

l t +

J / O

1t23 t o

Fig. 3-21 The lay Line printed aLong a flexible

)tise pro--iries tl""e needed iniormotion obout the

hose and serues to show whether or not the j rcse

has been twisted when i t was insta l led '

D. Types'of FlexibLe Fluid Lines, - ' { , ! , ' , .

1 . Low-pressure l tose - - :

Lo\4'-pressure air or vacuum hoses and lhe i ines to

some ai rcraf r ins l rumenLs are nol requi red co

carrl ' high pressures, and they may be of the lor'r '-

pressure type. These hoses have a seamless inner

iube and a re inforcemenr made of a s ingie iayer of

col lon bra id. An our .er cover of r ibbed or smooLh

rubber is useci Lo proLecL lhe reinforcemenL from

ph1's ica l abrasion. The maximum operaLing pres-

sure of these hoses var ies wi th thei r s ize and is

shown i n F ig . 3 ' 22 .

2. Medium-pressurehase

Medium-pressure hose is general ly ca l led 1 '500

psi tubing, but i ts nrax imum operal ing. pressure

var ies wi th i ts d iame[er . I t has a seamless lnner

tube and a colton braid impregnated wiLh a rub-

D a s hSize

3

6

- t u< a

- t o-20Fza- J Z

- 4 0- 4 8

Size

1 / 8J i t o

1 1 4f , / t o

13t32t t z

f , / 0

7 t 81 . 1 l 81 .3 /81-1 3 /1 62-3lB

M a x .Oper .

p s i

3 ,0003,0003.0002.0002,0001 , 7 5 0,1 ,500

8006005003s0250200

v bonci the sinsie Fis. 3-23 Medium-Pressure' hose

a

I

PA,GI:: LJ

c'.HAr,: A/ a. I LUI'IB ill(i

FLUID L INES P.ND F[ -TTINGSi ,

4AirlinesITigh-pressure hos'z

'hvo or tnore sLeel I lrairls 'are used f or ir igfr-

pressul :e h, rse, rvh ich has a mar: tmt lm pres;sure

i -ar ing o i 3,00() ps: . , and Lhe c 'ure: cover on ) r ig ! i -

p . " . r - r r . h , rse is smoolh, lo c i is t ingr ish i t f rorn

mediurn-pressure hoser. A syrrrhecic : u!] '"1.ln"'

] iner is use,d q'ibh hose fiadE ro*r!1' E:rroleurnp--OaUc *,tn d-tli e ; u 1€ r (,

" *,t tt t h-"!g--tl oi e i i s

ii;cI<lrna h a s a IJIIolr 1 tv fill e - 1\T'is e n e s' 99 a-ro

*nt Sltat;r itat""fic n'-,ii ttas a B'-l-!-rylf-ber inii€r--l inei-ani i gra:n iruter cover'

' fhe lay

i i ne f o : Lh i s hose i s wh i re .

:-----

t7ig. 3'2t> t\ - M'zd.itLm-])ressure hcrse t/ 'l'efLon

17 -- E'igh-pressure '4ose o'1 T'zflo;2, tuith tuto

Lave.s o, f spt : . ra l urap sta in less steel u i re wound in

ctpp<tsittt direct:ions. l\ st.ainless steel braid en'

c :ases t l te ent i re tube. C - A rnedtum-pre 's : ;ure

ircse' of Tefton protei:cted front ltetat ond abra'sion

lty a. twc-la.yer asbestcts Loom firesltieLd'

V. Fluid L'ine Fitt inigs

.A. At ; :achment to Ccmtr tonents

(4,)

D a s hSizet

- 6- 8- 1 0

< a

- 1 6

F'ig. i?-24 Higlt 'Pressurt' hose

4. I'.{ose of |lefLon

The synt .het ic res i r r proc iuced by DuPont and

knoq,n as Tefion hal; mztnv acivanLlgesi for ustl in

a i rcraf r f lu ic I in :s . ' le f l ' ln is unaf fec led b l ' fue ls '

I ub r i ca r i r l g ' l i i s , co ' c i anLs . o r so l venLs l f r a l a re

used in a i rcraf l sys-emis, ar lc i i i a l : ;o f inds ext 'en-

s ive use in miss i ler ; Lo carrv rhe fuels and ox '

i d i ze rs .

A seamlt :ss r :x [ ruc ied inner l iner of Tef lon res in is

coverecl rvi[].r a sLainiess sreel braid for rr 'edium-

pressure appl icat ions ' and iv ich e i ther Lwo br l r ids

or wirh a doi rb ie spi ra l rvrap of sra in less sLi :e l tv i re

for i r igh-pressure I i l res.

1L is imp,orLanL Lhe min i tnum l - rend rac i ius res ' r ic '

Lions be obr;erved tvhelr ' leflolt hc'se is instal ' led'

AfLc l r the hose has beet i in ser ' ; ice, i l 'v i l l " lake a

seL,' ' wh.ich meilns that. it rvil l become solrlev/nal

rigi<i, and if ihe hose is removed from l 'he aircrafl '

ir-nrust, not be benL al5ainst this set ihaL it ha:;

laken.

C . i : o

l . D .

I t J Z

| , t J z' ' ' 116o / 1 4

1 1 / 1 67 1 8

Ma;r.t )per .

p:si

3 ,0003,0003.0003,0003,0003,000 There erre l;wo bas;ic rvaYs

tinp;s Inay be a:rachedtap,3pscl pipe threaos anci

fitt:.ng.

1. Tatrtered PtlPe ,thrP'ads

Tapered p ipe : :hreacis seal

beLrveen ihe caPeled inale

in wh.ich fluid l ine .: it-

to a comPonent: bi '

by ' univer :sal bulkne'ar l

b' i the wedging arlLlot. l

lh rear l a r rd lhe laSrere i

i

j

iI

IIi

II

II

IIIIII

I

l!

IIIl

Fig. 3'26uicled bymole c:ttd

The seal of tapered pipe threa&; is .pro-l:he Luedgin.g ac:tiotx between the taperea

female thread,;.

F L U I D L I N E S A N D F I T T I N G S

EArnrnes

E L B O W A N 9 1 5

MS9058T E F L O N R i N G

M528778GASKET

G R O O V E

C O U p L 1 N G B U S H I N G

A N 9 1 O A N 9 1 2 E L B O W A N 9 1 4,----\ /-,5-1 rr'ilfir rrr i:-l

r--l_n I11Ilrili1HII,{mT{x \- / fillllllll- L:lI n,1til l l l l l l l l i lrrrii lNNr l=f li l l l l l l l l l I fFs|I]nmE-,|#///l [IIIIIIII[|-{N\\N ill j tllu[tlF U '--{"'il"r't---?W:--- PLUG \--J -ll'''U,'- - \ J

N I P P L E A N 9 1 1 A N 9 1 3

Fig. 3'27 T,,-PicaL taPered PiPe

di imcter of an i ron PiPe having

E L B O W A N 9 1 6

thread fitt ings. The size of a pipe fitt ing is meqsured by the inside

the same threads used on the fitt ing'

femaie threads. These threads taper 1/16 inch ro

the inch. Ei ther a smal l amounl of thread lubrr-

cant is placed on the male chread' or Lhese threacis

u." *.upp.d wirh a tirin scrip of Teflon Lape lo

assure ihat ttte frrrings u'il l screw together right

enough Lo form a complete se?l C3fg-nuslbe

raken when scre*'ing tapqred fittings il{e Jxst-

aluminum or magngqiu.m--hsu-sUCS Lnat lne IlI-

fiscastlng.

2. Uniuersal buLkhead fitt ing

These fitt ings have the advanLage that they can

be oriented in exactiy ihe correct direction and

rhen ttghrened in lhis posirion so thev wii l not

leak.

Before ' insr .a l l ing

a f i t t ing of rh is type ' an

AN6289 nut musl be screwed onto lhe f i t r ing so

thal i l comes up just above lhe groove cul lnLo

r-4,.--@, AN6289 NUT r----]

-----i / MS28778 =

\ l A 5 f \ E

F; - 9-9R

the Teflctnhousing.

A - Screu'ting and

C - Screw

thethethe

nut onto'the fit l tng untiL it is aboue the cutout portion of t^he tltreads. SIip on

o . n n s g a s k e , t . B _ s c r e u l t h e f i t t i n g d o w n u n t i l t | t e o . r i n g c o n t a c t s t h e

fitt i igln enough to align it with tlte hose. Hotd the fitt ing und turn the nut

T E E A N 9 1 7

n t t n

r A t J c . l ' l

Wtr NePatWAirlines

Ft -u lD L INES AND F ITT INGS

Lhc t-hreads- .\n i\,1 S9058 l 'ef ing and anl\,1 S28778 t]-ring 14as1<et. of l;heecorrecl size arecar t : fu l l1 , s l ipp, :d over Lhe lo ' rer lhreads inb, lh ie! I o , lve. Nor i , , roLaLe Lhr : f iL t . ing and Lhe nuLLog, : the:r i rLo Lhe housin lg unLi l the O-r ing jus; tconLacts the face of t .he l rousing. Hoid lhe nr-LLwir i - r a wrench an, l Lur t t t ,he f i f t ing in for f - i i 2Lurns. Lo ceuler- lhe O-r ing in t ,he groove, and lhenuse u l r Lo r )ne more fu. l l Lurn to a l ign the l i r t ingq'it.h t.he hose Lhart is rrt aL[ac]r Lo it. Vi/hen li-Le fi :-t . ing is a l igr - red. hold i t ancl r ig 'hren Lhe r lu t wi lh au ' rench unt . i l Lre nuL { tont .acts Lhe housing. Thiswi l l force r f re O-r in1g dcwn inLo the ch;rmfr : red holeand u ' i l l rnake a f iu id- i . ight seal .

E. Connec' t ior t o f P ' i .u id L ine.s

l. F'lared , ' irt ings

Autcnrotive flare-t." 'pe firt ing.s h;lve a 45-deg-reef iare cone angle, anc. ib is re lat ive ly easl , lod isrr r rgrr ish rnt :se [ icr ings f : -c ,m i t i rcraf t f i r r . ingswhir:h r:se a i l7-degri:e l: iare cone. There are,hori,eve:, trvg 1;yp6. of ai::crafr f itr ir.gs, bo1;h cfwhir :h have essenl ia l l l ' the sarne f lare cone angler ,h , , ; , r . i n r r , r n o t o l v r h . , o ^ F i r r ; - - ^

"herse f ib t jngs aro noL tnLel ._changee:ble. The ol<ler AC fitt ing rvas usecj e-:(Ler-s iveL,r ' terougi r Vr , 'o t - id V\ tar I i , and some of thesef i t t i rgs mar; sL j l l be found. They i , rok a g leat deaiI ike rhe more r ( )cent AN f i t r ings, excr :pt [har , [h , :Lhreacis go ali trre u'a,r' io t.re f,.are cone or rhet ACf i r t i ; rg , , ,vh i le or rhe, AIJ f i t t ing; th t : re i r ; a s ;hor_r jdei .be[u,ss l j lhe end of rhe lhrr :adr ; ani f lho cone. Alu-rn inum ai io ' , ' f i t . t in l ls of lhe AN c les i5;n are < i - r ,ec lb lue. u,h i le AC f icr . ings are dyed e i ther gray. or-Vel lCrr \ , .

in F ig. 3-3t1, lve see some t l rp ica i e l t rows; . Lere:r .crosr ies, anr i unions used for conrecl .n, l rubin,svri lh flare-l,yper fictings" The f ernakr L€ie €:rrjelbo', 'rs accept t,he bull<heild-t,ype uni orn or eibor';(ANl332 an, l A.N833). A i lu .d- t ig : r t r ;eal is ac-complished -gth these iitr j!gj_E!_lsitr-."t! 4 - + -

l ,{S:87?B O-ring gas}reb forc,ed irrUr -.! ire ch;rri-,-ferecl hoie in the female [ee or eltrow

I

ANT|21 ELI ]OW

AN{]27 CROSS

i-

l r l r ! r - i t| l i l i l t i li l l l ! I l l

\:

0 AN833 EL 3O\V

F:'Y:li ,--l l i l l i l i| - lJ-.lJL-l/

===; EEE

EA N 8 3 2 L I N I O N

t \N941 El_EiCr!1/

L

Ilt ,i .---\ _ .:

. .i-J--\' € - l

' .dEarc:

i i,---.f.-'_- -\

1 l

::--l#q

b-x:4

/€jG.€:)GFG--TiG

l---j[-

,r--\.--==:4,-:i-G-\

-<-|'_<_i

T--f---T--rt t ll t t l. J , - r J

:---.-'...a-<---

F'is. i '-29 'fhe threu<ls on an,4O fitt irtg extencj

t, ite wav to tlte fLare con,z ut\i le thc,.e is a steptiueen the end oi the threa.d:: an,j. the fla:.re c,onean AtY f i t t ing.

A N 9 3 9 E L - B O W

Fi17. 3-30 Ty.oicc.l AN f;t.ttirtgs ,for cc,n,oe,crin.g

fla,.ed tubi:.ng

4---_-ffi-:--_:

- c ; '

=iL__i-i-r--riS{:J

alLbe-o n

tffMm

A N 9 3 8 T E E

\€P NepalEArnrnes

The seal for a flareci f iccing is provide-d bv che

i iu .u.onu of rhe f i t l ing and the ins id-e of rhe f lare

of rhe tube. Excessive r ighlening of Lhe nul can

,".ioutfl ' ci istort Lhe flare and intensify a }eak'

r"air"--i i"t stop i l ' The recommended lorque fo)-

i lu . " - rypu f i tc ings is found ln .F ig 3-32 and these

values should not be exceeded'

r iI - , , . . - - - . .I

- ' o o1 Th ' f l " i r l - t igh t sea l p rou ided b7 ' af L S . J - J J r l t c l L u ' r r - L - ! i ^ - ^ ^'

' . :een the tnside of the flareci' f iared f i t t tng is betu 'een t -ne, In: . t :e u i lL'rube

and tie flare cone oi the fitt i .ng'-Excessiue

;i;;t;;;"g of 'th.e

nut can domage the flare' rather

than stoP a LeaR'

2 F io r t ' l c . ss i r l i r r l { s '

F la re less i i i u i ngs a rc ava i l ab ie i n a w ide va r i e l l ' o i

shapes ano s lv les. ar . rc i in F ig 3-33 we see some

tvp i ca l [ i r t i ngs

M 5 2 1 9 2 3 A D A P T E R

M S 2 1 9 4 U N I O N

M S 2 1 9 1 6 R E D U C E R

926 FLARELESS TUBEELBOW'90"

M S 2 1 9 O 8 B U L K H E A DE L B O W 9 0 '

M S 2 1 9 2 1 N U T

A l u m i n u m A l l o Y

T u b i n g ' N u t

T u b i n g F i t t i n g T o r q u e

O.D . S i ze i nch ' l bs '

20.3030.4040.6560.85

' , < - 1 r ' a

1 50-250200-350300-500500-600500-700600-900600-900850.1 0s0950.1 1 50

S t e e l T u b i n g ,N u t , i o r q u e

i n c h . l b s .

9 0 . 1 0 01 35 .1 501 80 .200270.300450.5006 50-700900-1 0001 000.1 1 001 200-1 4001 200-1 4001 500.1 800

r r q

3 / 1 61 1 4

5/1 63/81 t2f,ro

3 t47 t 8

1

1 . 1 ' 21 -314

t

- 2- 3- 4

- 6- 8

< a

- 1 A

- l o

1 " 6

tint3-32

enGE: fS

csap. A/ c. PLtJl /rBI i iG

F L U I D L I N E S A N D F I T T I N G S

-)

M S 2 1 9 1 3 P L U G

M S 2 1 9 1 4 C A P

Recommend.ed torque for f lare-type fit 'Fig. .3-33 TYPical MS,'YrcjW

l

a

t

P;\GE: ]. i

cuae: ̂ t / t j . I 'LU] ' f 3. i l i3

FLUID LII ' . tES; AI 'JD FITI+NGS .\@ NepalwFAirrines

F1f uffiffi,ffiffiffiffiffiffiffiffiffit$-'

Fig. 3-3'4

F'itti,ngs for flexibLe ho:;e

S'wa1Jed.tn iittirtgs

.FLet.ibLet hose Lrauing ::wa.ged-on end fitt ings

ISOCKE:T

t

N I P P L I :\ trt tt t,

c!-.

i lhere are two b;asic types c'f f i tt ings available forf lex ib le hose. Swag, :d-on f ic t ings are insLal led at .the frrcil i fy that manufactures ;he noser, arrd lheserI i t r ings can:rot be removerd and reu,sed. I f rherhose i s rep lace i . Lhe enL i r t : hc ' se assemb)y n rus tbe scrgpped an<l a new hose, ' :ompiete wi lh encli i t t i r : .gs, musL be purchaser i arrd ins la l ied.

0. ln te, .mediate-Dressure,hose

' ? p r : . r : h i , ' f i r . r . i n - c n r ) r ' m a l l v h : . r p t h r c e n i p c e s - a

r;ock,:L, ; i niprple, anrl a ;ruL. The socket. is screrveciinLo rhe end of che hos, : br ' lu : :n ing i r co lhe le f r .' f h i s

I e f t - ha r rd t . r r ead d : i ves t he socke - r iE :h r , x rolhe tube as che n ippie js s<:reu 'ed .nto i r .

, { n icp}e: , around whic l r lhr3 nu. l is p laced, scre i \ ' : ;inco lhe soci re l and forces che lubr : r igh l becrveenlhe r tuLs; ide of Lhe n ipple anc. lhe ins ide of !hr :r ;ockeL. Thi : ; squeezing ac l ion pro" ' i r les a ; ;oodr jLrong phvsical a[ [achrnenL be[we:n Lhe i - rose andt .he f i t t ing, r rnd forms a leak-proo1' seer l .

' fhe nul is held onLo Lh, : hose t r ,v the n ipple and i rs, : ree lo l ;urn. TI te ins ide o l lhe n ippie forms ihesealing :;urface which n'raLes w:ith t.he flare: cone ofr:he J:iLting, and Lhr: nr.rl pulis these [wo seeLiingr :ur faces log e lher .

N I P P L I :

Fig ,7-35 The reu.sabte end f i t t ing i ,cr nn tn-termedia i le p, ressure hose is made u.p or i a . so(k, ' - i . a

nippLe, and a nut.

The . ! '&F' ma1' , n imsel f . fa t r icare a f ler : ib le i rose

n' i lh reus;abie f i ' :c ings. To c io lh is . :he lenl r ' " r o f

the hose rnusL f i r :s t be c ie lermined. T 'h, : iengci t 'e-

Lween the ends of the fit l ings rnust btt Iounci and

becween five arrd r:igh.t percent a,Jc[e,l to th.is

discance for changes in dimensions; of ther t;uce

wilh pressure varialions, and for e:<pansion ancicontnrcLion of t.he aircraft.. Twice tire <ii:;tanqebe:lweren the end of the nipple and thr: inr;i<le o1'Lhe,

soct(ET'/' / NU'r

PnGE: i8

cH^P: !-.i a. ?LUI'IBIll3

F L U I D L I N E S A N D F I T T I N G SB@Z NepalEAtnrnes

H O S E L E N G T H

A S S E M B L Y L E N G T H

Fig. 3-56 TJ^"e lenst i t reuui red ior a hose is the c i is tonce bet t rcer t thc f i t f ing.s, p/u 'c thc requi rec i

o i th is iength for sLct .ch. , r i r r , ts t tL ' i .ce the d is tunce betu:een the end of the n ipple ond the er td r t f

t h e s o c h e t

musl be subtrac led f rom the requi red

of the hose.

J ' t c t o d ' r t

t h e h o l e i n

The nipple and nuL are assembled on Lhe assem-

b11 ' t oo l and l i gh tened so l he n ipp le can be sc re l \ ' -

ed in to lhe sockel by turn ing Lhe r lur . 1 'he nrpple

is then screrved in unt i l the nul bol roms on the

socker , and Lhen i t is backed of f f rom I i32 to L/16

inch lo a l low the .nut to turn f reei i on lhe tube

assembi l ' . \ \ rhen the assembiy Lool is screweci out

of rhe hose, bhe ins ide of the hose shouid be b lown

our wi lh compressed a i r and lhe enr i re hose in-

spected as lo i ts physical condic ion ' The hose is

then hydrostaticaiiy tesled to a pressure lhat is

normally lwice lhe working pressure of the hose'

and this pressure is heid for becween one and fivef f r h t l r o q

\ / l e t r

A S S E M B L Y T O O L

S O C K E T-

-----t

J A W S I\ i -\

:l9liiet,l p n r t h

The hose length is marked and both ends are cuL

of f square. A sockei is held in a v ise and che hose

is scrlwed into it unti l i*" borroms against rhe end

of the hoie. The'hose is chen backed of f tust

enough t6 prevent the rubber in the inner l iner

obscrucr ing the hole in the hose'

The end of the assembl l ' rool is )ubr icated and

forced into the hose and worked in and our ancl

arounci. Lo open up the inner l iner enough for Lhe

nrpple to force i rs waf in '

V I S E

7 J A W S

U S E W R E N CO N H E X

A,PTER

( B )

H O S E

I

SE

n

S H O U L D E RO F S O C K E T

P LN I P

I

A S S E M B L YT O O L (D)

S H O U L D E RO F S O C K E T

S W I V E L T Y P EA D

Fig. 3-57 A- Screw the end of t .he hose into the le i t -han<l t .hreacls of the sr tchet . I ' r :uue u smul l umoui t t

of clearance beluteen tl l te end ctf the httse and.the end ctf t l ie ltctL,e in tl le stt,chel' I - , ",: ' , ' , t:. i ' : ,: ' , ' : :;:

ir l 'oi, ,r 'Jt;;; ' ;;;r it into the'end of'the h<tse to open out the end ancl fr,trt:e the tuhe t ' ight intct the

soclzet. C - Screw the nippLe and nut onto tl le assem'bly tr.ttt l ancl force the nipp\ intrt thrt s<tcket' Scrett '

tlte nut down tight against'the sochet. D - Bddtr,:thcpur,o{f;p-baut',L/32;to:.1/J6jnchQrddremoue the"as*'

'semffitixi$rniffi,tltdifii&e.

o

I

R#$U Nepal:TF '

AirinesFLLnD LTNES nNo r t r f iNcs

A

F,Ar3E. -[c)

-------t

(A)

tJ

F'ig .l l-Sfi A - IJlou' out the compr]eted hc,se assembb, u'rth compre.;sec! air. ]] - Ex.zrnint? the tlose foran^, ' fcre ign tnat ter l .ns ide cf the tube. I t , .s possib ie for the n ippLe to: ;haue of f t , \ in s l ices cf the inn,zrl iner . C - I { l tc i .ostat icaLl , - test the hc,se osse'mb, ] t ' to tu: ice i ' ts nornzal operat i ;1g F,res: ;ure, ,znd holL i :h ispressure 1or bettueen one and f;:.ue rninute:;.

c . I .ou ' -Dressure l to .se

Reusabie et rd f i t , t , rng, ; may be asserrrb ler l orrLo lo iv-pt -ess l re hos, : in ntuch : .he sante v/a\ / as : .s donewiLh h ig l : -pressure hose, but . the sot ' t rubbelr rnnerl iner n. ra l ies lhe use, of an asseml>l r ' looI urrne-

cessarJ ' . . , \ f i : t ing czLn be scrrewed inro lhe r ru.L i ,chc ld the nrpple, and rhe socker is s i inpeci qr1: , : r . ]1c

end o l t fLe hose rat ,her cha.n being screrved on.\ \ :hen In€ nuc is r ighreneci asainsr . t .h : scc! :e. - . r :should be backec, of f iust eroug:h t i rar ihe nrr t cancu rn f r ee l r ' .

I

iIIL__t"ig.;i-;)!) Ainl errrtr:di.al c-con bc scret t '

I

- ! 1111t -p r? . \sure l t ,o n d lt i..g h -pre.s slr r(

ec l in t<s t l te socJ ;c t .

t s e e n d f i t t i r t g , e s L i n o u c r t h e , z n dIrosc.s do. B - , \ t ' i t t ing .sc.-e &,

oi the ) tose, , rather,zd i ,n to the nut u i r ' l

t lton

hc' ldscreu otr as tL,,et.he ,zi.oqtLe' so it

- H //t

F L U I D L I N E S A N D F I f i I N G SVZ NepalEAtntnes

F i g . 3 4 0 A _ S t r t p o f f t } t e o u - t e r c o u e r f , r o m t h e h i g h . p r e s s u r e h o s e o d i s t a n c e e q u a l t o t h e i n s i d e d e p t hoi the socket' B - rwist tLte hose *'" t1i'1""i:-';;:i:t:::::-:::,t:!:,"?r;,!!f[i':::i1:f:i."?:*oi the socnet u -

.'.*'!1 "'" "i:: :::::-";^^;"' '; ' -;;.",:

thp ninnLe into the sochet and the hose' LeaueoiL for black hose

"' "r*ii soay for gree,n hose' D - Screw ttte nipple into the soche

between 1i32- ond li\6-inch cieataice between the nippte hex and the socbet'

The nippte or the inslallation lool may be iub-

ricared with mineral oil if lhe hose is used for

mineral-base appl icat ions, bul i f the hose has a

Buryi l iner aid is used for Skydrol appl ical ions'

tn. , , ippt" musl be Iubr icaLed i iberal iy with I iquid

soap.

d. II igh'oressure hose

I{igh-pressure hose having Lwo wire braids and a

smooLh ouler cover can be made into a hose as-

r""-,Ufy in much lhe same wa'\ ' as the inlermediale

p." t t t t . hose' The basic d i f ference is that the

iut" . cote. musl be scr ipped f rom lhe hose for a

distance equal lo the depth of the sockel'

in F ig. 3-40 we see a h igh-pressure hose f i l f ing be '

ing i istalled. This one has a male,thread on the

nifiple, ralher Lhan provisions ro lbf "

riut' and

,o-irl urr"*bly tooi is not needed' The nipple is

]ubricated and screwed directly into fhe sockeL

and into the hose'

The h ieh pressures LhaL exis l in mosl a i rcraf t

;yi.";k sysLems and ihe extremely cri l ical

.rutur. of the fluid l ines make it exlremely impor-'

|ani Lha! all hoses be fabricated and lesled pro-

perly. For this reason' and because of the diff icul-

ly in urru*bi ing some of the larger hoses ' i i is

.i-rnon practice for all replacemenb ho.ses bo be

pu..n"."a from the facfory which produced bhe

T A U : . < - . !

^ t ^c H A P r A t C . P L U i : : i i l l 3

Wtr Nepatffi@trAirlines

FLUID L I IJES; A i \ ID F IT ' I INGS ,

aircr i l fL or f rom apProvr ldequiprpecl bo fabr icat ;e and

I = U a L t 5 L - i t l : . - - i a t a :

i ^ ^ - * L ^ . . -L U : ! L I I t r : :

Flu. id L ine I ns ta l ie t ton

t7outing an'j Se cu rt rtg

l \ l l f iu id l ines should t ,e rouied t . , : rugh :ne a i : 'c:raf L in su<:h a q'av tha [ : ire,r- -... ' :1. hi.- ' 'e t]-..,. h n . l p q f n r a r - r i c a l l e n q l h . I l r : : [ o . - : . s a l . : = o . : a f ," - " b ' ' "

[ )earanc€r anr ] ease of ar , tachni :nL. : . . , r f ' t : -e i in==,should f r r l lorv lhe s: ruccural nern i* :s o i :he a: :c ra f r anc l shcu l c l be secu re t i r ' , ' : r h t : . . app : ' oo r i a : ic lamps lo tbe st , ruc lure. In F! ;1. 3-{ - v , 'e i=. r 'e c i . te ,pproxi rnaler spacing o l t ,her surpo: : . recu: :e<l io :r ig id f lu id l ines.

S U P P O R TLEA,ST:l/4E D G E O F

Fig. 3'-a2 Stpprtrt all f,!uid l ines uthere tl;.e'v passthrouqh t t hc le in the st ructure.

[-

Fi ,7, 3-43 Ai l tu :b ing should i tau,z ar leost or ;ebe , t c i : o obsc ' rb t he s t ra in : ; f r om uLb ra t i o r ' " , zn i

l rcm the d i rnensior , ,a l changes of t , \e z i ' 'c 'c i t< i t ' t t a i ' t r a r l r r o t n t o m n o r l r t t r o e , \ n n q r ' <

Flexi t , ie l lu ic i l ines rnus[ have betrveen f ive ance igh t pe r :en l s i ack . r o a l l r r r . r ' f o r l he ch , rng , : i r .c i i rnensior is of t f re hose carrsed b1 ' tbe pressu:eancl fcr v ibrac ior : anci e:<pansion o i l ;he a i r f : :arne.I t i s i r noo rcanL l ha t l he I av l i ne 'be s : r , l i g i r L r vhenth r : hose i s i ns ra l i ed . An1 ' sp i ra1 ing o f l he I av I i nei s an rnc i i ca t i on Lea r l he hose u , . as [ t ' i sLed wnen i iu 'e .*s ins l ; r l lec l . and i t . r ' i l l be undr: r a in uni r iean)our) [ o f s t , ra in w.ren thel re is prersr ;ure in ihel i ne .

I f a i ' lu ic l l ine rnust pass near a hob exhau:stmani f , : ld , the i iner mrrsI l :e protected by a : ;u i tablef i re shie ld. For th is purpose an asbes;os bra idmay be fas lened around lhr : hose.

1/I

11

=1II

ROMME' I

\ i-t- i

/r\\){J

L-TUBE: O .D .

1 /8 -3 /1€ i

1 / 4 . , 5 / 1 6

J , O - u Z

5 / 8 - 3 / 4

1 - 1 - 1 ! 4

l - t r z - a

DISIAI .JCE 3=TWEEt , I) u r F U n | 5

1 4 "

t o

22"

3 C "A a "

I r ig .3-41 Spoclng bet t t een s*)po-craf t tubing

' ? r r : : t Q Q . :

) t r s imp ,o r tan l t ha t l h i : r e be ro p ( r : . . i r i i i i - . ' o l ' t i . ,l i n p c h a I i n o a r ' : i n s t . a n l c o : : : o l c c : - : o l ' : ] o I L i o : :o f r he a i r c ra f l s t , r ! cLu r€ : . an i 1 : mus - r o l b= a l l o " ' . -ed lo come in conLa, : : u ' r i r . e l i - - : ica l i ' . - i r i : . ; :bund les o r condu i t ca r r v i ng e iec r : ' : : . : n ' i r : s . I f : :i s i n rnos rs ih le L r r se "na ra te f i u .C l i : . . = f r c= e le t .t , r ica l u ' i re bundle: ; , the r t i : t br : : . : ie r :usr- br 'rouLr :d rabor ;e t ,he f lu . c I ine. arrc : : r : :s l r . -c : l a rnped secu re . \ ' I o l f ) e s t : ' , : ( : : u r? 1 . p : , : ' . e ] r t : .c o n r . ; r c t . i r q t . h e f l r r i c i ] i n t . U n i = : n ( ' , , : i l u n : s : a n c r : :' ' b

" " '

s ;hou ld x r v i r ' : bunc i l : be supp , - . - ' - g i : ' : i u " . . i ne ' : : '' n . i i n p r a r - \ ' i n ( ' f l a m r ; a l l l e l : ' ' l r c

. \ l i bends n r , r s l be l oca teo i n s ' . : ch , r . ' . : \ ' 1 i " . : : l h€ ' . .<:an be s;upF,orL( lc i t rv c iar : rps sc) i : . : : t i ' t ' i s t . re: , ,I r om v ib raL ion anc i f r o r : i expans i t , : ' nc i i r r r : r . r ac -I r / r r 1 c n r \ l n l a c e C o r l h c , f i c t - i n r A l l : - : r s o : : u b i r . :rnus t have a t le , rs t one benc i i t? i r r ' - : : i h e : : : c i n g , i-...---t . o a t ) s o r b L h e s e s t r i l t n s

Al l l incs c; t r rv i t rssLru, : lure b, r , us ingclan ' rps.

[uel mus' . be ; . ,i - r ^ , , - ^ 1 1 , . i - ^ , - . i jr l r L t r t s r d r l - \ . . r u l r l r : _

:rdeci l c, I ie' r ' n p

i : ' r l n n - '' " ' - - _ t t s - l i

PplGE:22

F L U I D L I N E S A N D F I T T I N G S

I

:i w R o N G ' I

W R O N G

Rx\\friU

R I G H T

W R O N G

. , - o r , ^ a n.x ib le hose must not be st retchecl t ight bbtu{en two f i t t i r tgs. I t must haue bel roeenf L g . J 4 4 ' t ) - . n

l L Y .

; iue and eight percen't sLach. B _ The Lay l ine must run straight aLong 'the

n"', ' ' : !::!::1 :::^,,:, ' ,:,: ' :,

;;r";;;;t;;;:; ;;;" i l was instayed. c - wtLen a'ftexibLe tine is ,oitn..J near e hot exhaust manifotd it

must be secured to the aircraft structure so'Ehat it cannot t.ouch tlte hot metal. D - Be sure to <tbserue

the minimum bend radius when install ing hose. It wouLd haue been better to use a 90o elbow for one of

these fitt ings. E - Be sure to altow sufficient slach when attaclting a lnse to a mouable cylind'er' F -

( B )(A)

(D)

W R O N i r

F { l L : n I

W R O N G

Always usi the Proper fitt ings to preuent unwieldy lengths of hose'

I

IL is i rnpor lar t t . i r i i l - ;he morrsrned( o l acLuaLingc:r ' l :nc icr rs be cc 'ns idor- rx l w.r ren a l lzLchi : rg thei r f iu id

i iners. ' fhere nrust . i rp no k ink ing of Lhe l i r ies a l

e i t l i e rend o f l he l r a i , : r l o l ' l h r l cv l i nde rs o r i n a t t v

inLr : rmedia le Srosi t i ' r i t .

The min inrurr r b, ' r rd rac i ius must be observt :d

wh , :n i ns l t L l l i ng f i ex i i , i e l i ne i o be su re Lhz r t . Lhe

hose i s no t ex , i cs i s i \ i ' l v sL ra i r red .

i f a f l u i d I i ne rnus I r , ' r ouLec i r h roug t r E J )assenge ror , l rev/ comprrrLmer l i or r .hrcugi - a b 'agp;ag€' co l r l -

par tm( inL. i l n tusL i le ins ia l ieC in such a lva ' ; ' lha i

i t . cannoL be us;ec i as a hand hoid. ! \ ' -h , : re i ines pass

rhrough a rvheel rve l i . thev mLlst be proLeclec i

f rom abrasior f r ( . In rocks at rd c l i r r lhat ma1' be

rh rown up i n to r l r v ' e l l whe 'n Lhe a i rp lane i s cn

th t g roun t l .

M I N I M U M B E N D R A D I U S F O RI NTE R M EDIAI-E. F' R ESSI.J F] E

F L E X . I B L E I - I O S E

Fig. 3a5 .Min imurt , )end radi i for tn te r rne 'a ' .c :e-

Dre: ;sure f tex ibLe f tu ic i l ines

U } \ J N

I { U T \ T B E RM t N t t i u i i

B E N D F A D I U S

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un ron anc i t he co : r -ec t nuLs i ns la l l ed on Lhe tube .

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