DMWR-9-2815-220
AVDS-1790 ENGINE OVERHAUL STANDARD
DEPOT MAINTENANCE WORK REQUIREMENT
DMWR-9-2815-220 - Page 121 of 1422
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5-7.
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DMWR 9±281²³220
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approximately 350 degrees± 35 deGrees F.
Control heat process to avoid INcipIent
Melting, excessive grain GrowtH² or other unDesIrabLe structura³ changes w´icH
MIgHt reDuce tHe MecHanical properties .
¼½
CAUTµO¶
·ven prehe¸tInG is requIreD wHen welDing large sectIons
of a casting.
A welding torch sHould onLy be useD to
preHeat smaLl sections ¹aPProxIºtely 1 sQ» in. area}
¼reheat sho½LD not eXceed 3¾0 F.
¹
g.
WelDin¿.
(1)
Cracks.
Àhe inert Gas sHielded arc weLding process sHaLl be useÁ wHen
making repaÂrs on alumIým alLoy.
After casting has reached the prescribeD pre-
Heat teÄperatureÅ
Æ
posItion the castIng Into the Most advantageous weLÇing positionÈ
Cover castInG wItH asbestos bLanketsÅ except for area to be weLdeD.
ÉelD tHe o½t-
sIDe miLLed groove with a good root welD.
Apply ÊILlet weLDs untIL groove Is
cËosedÌ
Rotate casting and weÍd insiDe groove iÎ tHe same ManÎer if doÏbÐe
V
is
usedÑ
Òemove asbestos bLankets and allow castings to cool progressiveLy to room
teMPeratÓreÔ
Õ2) Fractured anD mIssinÖ MetaL.
Fo×ØowinÙ tHe procedure oÏtlIÎeD IN (1)
above, pLace insert piece in opening, alIgn and secure with cLaÄps or tack weld
iN tHree or four pLaces wItH one inch welDsÌ
¼Lace a good root weld In groove
aND apply ÊIllet welds ½ntIl Groove Is closedÌ
Rotate casting anD weLD inSIde
gÚoove iÎ the same manneÛ.
ÜOÝE
THe ÞeÄperatÏre oÊ tHe castIng sÏrrounDIng the weLdeD area sHo½lD not
exceed ß95 degrees.
àÊ necessaryá stop weLDIng² cover castIÎg with
asbestos bÐanket
â
and allow to cool to a satisfactory tãperatÏÛe then
resÓäe weLDIngå
h.
æInal insçectIon and cLean uè.
RepaIred cracks and areas where metal Has
been rep³aced mÏst Be r¸dioGr¸phically inspecteD and be eQuaL toá or better tHan²
reference standard é² TACOê ëìí 113á Apr 69 (availabLe from îïTACOð ñRòóA).
ALl
oÞHeÛ areas sHall be inspected by Dye penetrant.
íefects Must be reôwe³deõ in
aöcordance witH above M÷thodsÑ
ðeasure
casting and coMpare diMeÎsions taken
before repaiÛÑ
íImensional change wilL not exceed that as speciÊieD
on
applicable
engIneerIng DrawIng² except as noted.
Check øachIned s½Ûfaces foÛ warpage or
ùtheÛ DiMeÎsional changesÔ
Clean seaMs with a wIre br½sH and remove weLD beads
and all sharp edgesÔ
úûray entire repaiÛed area.
ReMove excess flux with sÏIt-
able Materialü rInse with c³ean waÞer² DryÅ and anodize.
¼ressure test oiý passages
/J
that Have beeþ ÛepaireD to ÿĀ psi air; use soap soLution to detect any leakā
¾Ă8Ô
AssembËyÔ
a.
ăeneÛaĄ.
Extreąe care m½st be exeÛcised
in
aLl ¸sseĆbly opeÛ¸tIons to insÏre
ćJ
5/11
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