Welding Tips and Tricks

Im knew to this so please bear with me. I work as a welding suppervisor in a shop where we build alot of prototypes and one offs of rail and mining equipment. My experiance is almost exclusively MIG, almost 0 TIG altho i do have one here(dont know how to set it tho). My dilema is that we have a knew customers and with it brings a whole lot of High Pressure Hydraulic Lines. I have done alot of air line and some hydraulic tanks, lines ect. but nothing like the 7-10,000 PSI that these require. Can someone help me with right process. I dont want these things blowing out and costing my bosses lots of money or worse, hurting somebody.Any help i can get would be greatly appreciated!

What size are the lines? What kind of SS? What kind of pipe/tubing...(thickness, Outside Diameter, inside diameter)? I would definitely recommend TIG welding that kind of thing. It's the easiest way to get the best weld on hydraulic lines. I imagine your doing socket welds. You could also use Swagelock (sounds like "swedge-lock") compression fittings but they are $100+ a piece. I've done quite a bit of this so gimme some details and I'll give ya any knowledge I got

Have the same Sound like a job for swagelok, kown That a 12,7mmx1,65mm pipe Can take 600-700bar and you Can Bendt

batilden69 wrote:Im knew to this so please bear with me. I work as a welding suppervisor in a shop where we build alot of prototypes and one offs of rail and mining equipment. My experiance is almost exclusively MIG, almost 0 TIG altho i do have one here(dont know how to set it tho). My dilema is that we have a knew customers and with it brings a whole lot of High Pressure Hydraulic Lines. I have done alot of air line and some hydraulic tanks, lines ect. but nothing like the 7-10,000 PSI that these require. Can someone help me with right process. I dont want these things blowing out and costing my bosses lots of money or worse, hurting somebody.Any help i can get would be greatly appreciated!

Welcome, batilden69,

I've done quite a few code welds that I had to test to 9680 PSI (this was 1.25 X MAWP of 8800PSI). The service was liquid hydrogen, not hydraulic fluid, but the piping was all 3/4" 304 SS, schedule 160, and because of the pressures it had to meet ASME IX B31.9. It was TIG all the way, and the customer required 10% of my welds to be x-rayed. For convenience, the x-ray averaged 25%, but regardless, at those pressures, boiler code will most likely apply (as the best system to have esablished WPS's and standards for those pressures.

Steve S

I'm with Steve, that application should have a WPS or have one established/created. Tig all the way and I'd expect an xray and bend test minimum.

Any one that considers welding a high pressure line should be aware what effect even the smallest pinhole or crack could have if a hand gets into the leak path. Fluid under high pressure that leaks thru a crack or pinhole can cut thru a hand that at first look looks like nothing to worry about that later leads to a long and painful treatment.

http://www.safequarry.com/toolbox/Highp ... juries.pdf

AndersK wrote:Any one that considers welding a high pressure line should be aware what effect even the smallest pinhole or crack could have if a hand gets into the leak path. Fluid under high pressure that leaks thru a crack or pinhole can cut thru a hand that at first look looks like nothing to worry about that later leads to a long and painful treatment.

http://www.safequarry.com/toolbox/Highp ... juries.pdf

Good reminder - one of our local farmers got "injected" with hydraulic oil in his leg.