im stumped need some ideas

[mach1]

so this is the short story.
any mechanics techs and engineers are welcome to take a stab at this one.
so im building a 50GPM test stand for the boeing company.
im runnign a motor, main pump and bost pump so im having a leak on the boost pump suction port, the oil seeps around the flange between the fitting and the pump and around the bolts holding it in place. this is what we did to try to fix it.
1) change the flange and o ring
2)put some teflon around the threads of the bolt
3)remove the lock washers from the bolts
4)place a teflon back up washer under the o ring to bring it up so i seals more
everything we tried had no good results and me the tech and engineer are stumped.
does anyone have any ideas how to stop it from leaking? epoxy and locktite are not options.

[werase643]

you are having a problem on the suction side?
not the pressure side?
impressive

[mach1]

i know this is the first time i ever seen thisbut i have only been doing this about a year and the engineer said it was his first time seeing this and he has been doign this for about twenty years. and the fact that its the suction side which has no pressure has me stumped.

[werase643]

is the tank open to ATM?

sounds like the tank is under pressure.....

the flange mating surface needs to be decked
or have an o-ring relief cut into it....inside the bolt pitch diameter
and the tank flange needs the bolt holes sealed from the pressure side....

[onefastgs500]

maybe a copper crush washer?

[Jughead]

BFH it'll fix it every time.

Like Wera Says Something is Out of Jib and Needs to Be Decked.You may try to find some Stat o Seals.

Also I have really No Idea on the Setup your Working on without pictures.Being a Dumb Farm boy all i've ever Run into is Water Pumps,Fuel Pumps,Hydralic Pumps,Pool Pumps and Air Pumps. I'm sure If I were there I could Get er Going.

[werase643]

J,
I'm positive you are qualified.....but ya ain't CERTIFIED to touch it....
:cry:either am I......

sounds like the supply tank is the problem....is it new?

and the flange is probably too thin...beef it up
is the suction fitting.... pipe thread or standard?

[Jughead]

J,
I'm positive you are qualified.....but ya ain't CERTIFIED to touch it....
:cry:either am I......

sounds like the supply tank is the problem....is it new?

Yeah I'm Sure I'm not. But I could Flash my Lunch Card from High school and say i'm a Certified Know alot,Pipe layer and Diesel Fitter.

[GeeP]

It's a little difficult to troubleshoot something without the schematic.   

Obviously, you have positive pressure at the suction port. 

Pump installed backwards? 
Check valve backwards? 
Motor starter reversed? 
Sump not open to the atmosphere and/or without sufficient expansion capacity?
Manufacturing defect on the flange?

Is your shop ISO 9,000,000,0,0,1797.d90 certified?  That could explain it.  (Inside joke) 

[Jughead]

It's a little difficult to troubleshoot something without the schematic.   

Obviously, you have positive pressure at the suction port. 

Pump installed backwards? 
Check valve backwards? 
Motor starter reversed? 
Sump not open to the atmosphere and/or without sufficient expansion capacity?
Manufacturing defect on the flange?

Is your shop ISO 9,000,000,0,0,1797.d90 certified?  That could explain it.  (Inside joke) 

All of that AND Possible Blockage? In a Hose or Pump? Is there a Return Line that Could be Feeding the Fluid back into the Tank too Fast Causing a Pressure Build up? Did the Plumber Install the Shutoff Valve Backwards?

[mach1]

everythign mechanicaly is good the unit runs and runs good we get about 50GPMS at 3100 psi when testing an aircraft but its that small leak that is stumping us no backpressure, tank cover is open so not pressurized and nothign is mounted or plummed backwards. the first thing that came to mine was the casting on the BP was cracked so we changed it still elaking we changed the flange(i think its about 11/4 thick im sure thats thick enough and its pipe thread im running a flange with a -32 90 deg female to a -32 male to a -32 pipe to a -32 JIC then to a -32 suction hose).
ill tak emy camera to work and take some pics ill even let you guys knwo if we fix it and how i may even post a video of us testing it.

[Alphamazing]

everythign mechanicaly is good the unit runs and runs good we get about 50GPMS at 3100 psi when testing an aircraft but its that small leak that is stumping us no backpressure, tank cover is open so not pressurized and nothign is mounted or plummed backwards. the first thing that came to mine was the casting on the BP was cracked so we changed it still elaking we changed the flange(i think its about 11/4 thick im sure thats thick enough and its pipe thread im running a flange with a -32 90 deg female to a -32 male to a -32 pipe to a -32 JIC then to a -32 suction hose).
ill tak emy camera to work and take some pics ill even let you guys knwo if we fix it and how i may even post a video of us testing it.

I have some ideas...

http://en.wikipedia.org/wiki/Capitalization
http://en.wikipedia.org/wiki/Punctuation
http://en.wikipedia.org/wiki/Grammar

Just a few thoughts.

[spc]

Yeah, that last post would make an english teacher go nuts.  Ain't like I really care though 

[mach1]

grammer.........ehhhhh who cares........... i know my grammer sucks and i try to fix every little thing on my posts but it was late and i was tired so "pu tuhs"<-----

[werase643]

does it leak sitting there or only when running?

I understood what he said......if ya ain't got sumtin to add to the discusion.....

[sledge]

Despite some very good answers and contibutions in this thread I would be tempted to ask the question in a forum more orientated towards the subject.........like this one:

http://www.eng-tips.com/threadminder.cfm?pid=1083&page=1

[werase643]

Ian,
Some of us live for this sh*t
it remindes us that we really do know how to think

also this is in O&E....anything other than GS.....

I'm now going with poor tank design is causing the leak

[mach1]

ok so we got it fixed today, they actually went with my first suggestion getting rid of the o-ring and using a felt gasket . i forgot my camera today but im charging it today and am going to take some pics tomarrow.
thanks all

[werase643]

crappy mating surface with the o-ring.....kewl
glad it's fixed