Leaking CGA540 USD J62 Manifold

[KD8CVL]

I'm restoring a recently purchased USD J62 manifold. Tried Captain's 2 12 inch wrench method but cannot get the CGA540 connections to seal 100% (very small leaks, both sides) above 300psi with reasonable torque (guessing about 30-40 ft-lb). Have not tried any goop, only bare, alcohol cleaned brass. The surfaces show some minor casting porosity defects and have scratches that I've smoothed out with toothpaste. Is anyone aware of a tool or method for resurfacing both male and female CGA540 sealing surfaces. I've been searching without success and am about ready to JB Weld the whole thing into a solid manifold. Is there a retrofit method using polymeric seals like on current oxygen fittings? Will most appreciate any forum suggestions. Mike

[gj1963]

Have you looked under the J valve seat? I had the same problem and it was the seal under the seat. I kept thinking it was the connections as it leaked around the threads and came out at the connector.
See thread:
http://www.vintagedoublehose.com/forum/ ... =41&t=6175

[KD8CVL]

Thanks gj1963 for tip. You may be on to something since the reserve side CGA540 looks good to my eye, could be seat leaking around the insert. The Right side has some casting porosity in male center section.

[antique diver]

The most likely problem is brought up by GJ1963, so definitely replace that seal in the reserve side first. If the problem still exists, there is a cure that I use with a thin copper washer shaped over the 540 nipples. It is soft enough to seal up scratches and nicks that won't otherwise seal, and excessive torque is not normally needed.

[captain]

The most likely problem is brought up by GJ1963, so definitely replace that seal in the reserve side first. If the problem still exists, there is a cure that I use with a thin copper washer shaped over the 540 nipples. It is soft enough to seal up scratches and nicks that won't otherwise seal, and excessive torque is not normally needed.

That is a trick I also have used.

[KD8CVL]

Captain - Thanks much for your fine info & picture. I've been considering such a concept for scratched up 540 nipples. Would appreciate any source/fabrication info that you can give. McMaster Carr carries flat copper washers but so far I've not found conical ones. Thinking about trying flaring tool as a die to atleast approximate the angle before mating up the 540s. Mike

[KD8CVL]

Antique Diver & Captain - Thanks much for your fine info & picture. I've been considering such a concept for scratched up 540 nipples. Would appreciate any source/fabrication info that you can give. McMaster Carr carries flat copper washers but so far I've not found conical ones. Thinking about trying flaring tool as a die to atleast approximate the angle before mating up the 540s. Mike

[antique diver]

Antique Diver - Thanks much for your fine info & picture. I've been considering such a concept for scratched up 540 nipples. Would appreciate any source/fabrication info that you can give. McMaster Carr carries flat copper washers but so far I've not found conical ones. Thinking about trying flaring tool as a die to atleast approximate the angle before mating up the 540s. Mike

I was lucky enough to find some conical washers many years ago, and it was easy to shape them to fit the 540 nipple. Over the years I have used all but two of these, and would like to keep them at least until I can find more. These were originally designed to fit in JIC flared fittings so that scratched/damaged JIC ends would seal. I haven't seen them anywhere since, but I'll bet they are still made.

If not available, I think you could take any suitable sized flat copper washer and shape them with a tubing flaring tool to end up with the same results. The trick is just to keep them centered on the nipple during assembly... they will conform nicely to the shape if you start with the flared washers. I'll see if I can find a source and let you know. Please do the same if you find some.

[KD8CVL]

I may have found some conical copper washers. Found 3an and 4an sizes (not sure what corresponding dimensions are yet). They are used for fixing problem hydraulic fitting leaks (ie: automotive brakes). If I find worth while conical sealing washers I'll let you know and we can stock up.

[antique diver]

I may have found some conical copper washers. Found 3an and 4an sizes (not sure what corresponding dimensions are yet). They are used for fixing problem hydraulic fitting leaks (ie: automotive brakes). If I find worth while conical sealing washers I'll let you know and we can stock up.

Those are pretty small, corresponding (if I remember correctly) roughly to size of the flared ends of 3/16" and 1/4" tubing. AN sizing is the AN number/16. The size we need is probably more like a 6 or 8 (3/8" or 1/2" tubing flare). I'll try to figure out what size I have.

[captain]

Use an appropriate sized flat copper washer. Insert a short length of the appropriate size wood dowel into the male CGA fitting and slip the washer over the dowel to hold it centered in position. Assemble the manifold and tighten the nut to form the washer. Dis-assemble and remove the dowel. The washer should be formed to the correct shape.

[KD8CVL]

Use an appropriate sized flat copper washer. Insert a short length of the appropriate size wood dowel into the male CGA fitting and slip the washer over the dowel to hold it centered in position. Assemble the manifold and tighten the nut to form the washer. Dis-assemble and remove the dowel. The washer should be formed to the correct shape.

Thanks, once I find washers I'll try it.

[KD8CVL]

I may have found some conical copper washers. Found 3an and 4an sizes (not sure what corresponding dimensions are yet). They are used for fixing problem hydraulic fitting leaks (ie: automotive brakes). If I find worth while conical sealing washers I'll let you know and we can stock up.

Those are pretty small, corresponding (if I remember correctly) roughly to size of the flared ends of 3/16" and 1/4" tubing. AN sizing is the AN number/16. The size we need is probably more like a 6 or 8 (3/8" or 1/2" tubing flare). I'll try to figure out what size I have.

Thanks, Secoseals.com makes such seals for aerospace. They have a good pdf drawing for range of sizes. Yes, Army Navy 6,7,8 look better. However, Seco seals have a small locating diameter that fits over male and may have to be removed. Most likely will fab my own.

[antique diver]

I may have found some conical copper washers. Found 3an and 4an sizes (not sure what corresponding dimensions are yet). They are used for fixing problem hydraulic fitting leaks (ie: automotive brakes). If I find worth while conical sealing washers I'll let you know and we can stock up.

Those are pretty small, corresponding (if I remember correctly) roughly to size of the flared ends of 3/16" and 1/4" tubing. AN sizing is the AN number/16. The size we need is probably more like a 6 or 8 (3/8" or 1/2" tubing flare). I'll try to figure out what size I have.

Thanks, Secoseals.com makes such seals for aerospace. They have a good pdf drawing for range of sizes. Yes, Army Navy 6,7,8 look better. However, Seco seals have a small locating diameter that fits over male and may have to be removed. Most likely will fab my own.

That is the same shape that I started with, and they shape out nicely over the nipple when snugged up. I think mine are #6. The hole in mine after shaping a little range from 0.328 to 0.33", and shouldn't have changed much, if any, from the reshaping. Maybe they can confirm that is a #6 before you order them.

[KD8CVL]

Parker makes flare gaskets (conical shaped copper washers), 3/8 tube size is 2GF-6. Grainger sells this size as 5WRW3 (currently 10 for $9.01, page 4159). Got mine today, they fit J62’s CGA540 nipples well and look appropriate in seats prior to tightening. Out of the box mine measure: 0.540” Max OD by 0.240” Min ID. Sealing surface is 0.175” long by 0.028” thick. FYI - Parker lists them for 1000 psi service with 3/8 SAE tube flare. This spec is probably overly conservative for our application considering the greater robustness (stiffness and strength) of CGA540 over standard 3/8 SAE tube flare.