Welding hydraulic fittings

[Strostkovy]

I find it very convenient and strong to weld couplers into a plate for securing fittings for hoses or quick disconnects. However, I've never done it for a 3000 psi system. Is there any concern about the weld reducing the strength of the fitting, especially if the working pressure of the fitting is only 3000 psi?

Here is the actual fitting: https://www.surpluscenter.com/Hydra...le-Straight-5000-08-08-Adapter-9-5000-8-8.axd

Bulkhead fittings would also work but they tend to be expensive or terrible or both. I can fab up various styles of clamp bracket but that is less convenient.

 

[DDoug]

My concern is fatigue.

 

[R. Dan]

A lot of those fittings are cut out of free machining steels like 12L14. No way to know what it is unless you know the factory and what they use. That won't happen. So if you weld those you are taking a chance, especially if you are welding it more than once.

 

[Phil in Montana]

A lot of those fittings are cut out of free machining steels like 12L14. No way to know what it is unless you know the factory and what they use. That won't happen. So if you weld those you are taking a chance, especially if you are welding it more than once.

100% right 12l14 is widely used and WILL NOT WELD, if you must silver solder or braze...Phil

 

[deltap]

You can buy forged steel fittings designed for welding. Then no worries the weld will be stronger than any pipe thread.

 

[MaxPrairie]

Need to be 100% sure your weld is free of voids and pin holes. Leak check at shop air pressure. I would think at 3000 psi, a pin hole will turn into a laser. It is easy to see while tig welding if the material you are welding is taking the heat well and leaving a clean bead. The hot glue gun is more difficult to distinguish.
+

 

[gbent]

I have tig welded quite a few fittings, usually to make adapters that aren't commercially available. I haven't found one yet that wouldn't weld.

 

[climb-101]

I have tig welded quite a few fittings, usually to make adapters that aren't commercially available. I haven't found one yet that wouldn't weld.

this has been my experience also. never had any issues tig welding thing up.

 

[Strostkovy]

I've had no issues mig welding these fittings. I'll look for some forged fittings

 

[boslab]

Buy weld fittings, sockets elbows etc tig them ( to be honest they’re too small to stick weld really! I’ve never had one fail, even 3k pressure, I do mine multipass, root fill cap sometimes root then cap but 2 runs, I wouldn’t be comfortable with single weld myself, if there’s a void or something you’ll find it second time round, if there is gash it out with the angle grinder and re weld .
Good quality pipe or tube and good quality fittings, if there Chinese discount specials don’t use them, he’ll the threaded ones are rubbish, they wonder why they have difficulty making jet engines!,
Mark

 

[Peter from Holland]

He is welding them into a plate Not on a plate So I presume the weld does not see any oilpressure

Peter

 

[Strostkovy]

He is welding them into a plate Not on a plate So I presume the weld does not see any oilpressure

Peter

Correct, the weld will not see any pressure.

 

[Strostkovy]

I think I might weld in an oversize coupler, and thread compression fittings or cable glands into each side and pass a high pressure nipple through it. That should be stout and safe.

 

[scsmith42]

I TIG braze stuff like that all the time - no issues in 40 years.

Weldable pressure fittings (such as these from McMaster) may be a better choice though since they are rated for your pressure (and are fairly inexpensive too).

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