Tangent Thread on B31.3 testing

[dcasto]

our new field construction manager, having only build pipelines under B 31.8, has a new idea for testing refinery piping he is working on. The person is building all the piping on the pipe racks and doing 100% xray. After the lines are complete, they will dismantle all the pipe and rejoin it on the ground leaving out the valves. Then they will do a 4 hour hydrotest (at less than 40% of smys). Because the fluid in the piping system is not compatable with water, they will dry the line and disassemble the piping and place it back on the racks. Then they will pressure test the line to 100% of the NORMAL operating pressure and call it good.

The reason is that they are afraid of a pnuematic test that would require testing to 2000 psig, the Normal pressure is 1450 psig. That 2000 psig is to scary.

What say you? Has the piping system been tested to B31.3?

 

[BigInch]

Fire him. Then send him on over to us. We could use a guy like that.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[moltenmetal]

Is the 4 hour hydro being done per B31.3, i.e. at or beyond 1.5x the design pressure times the ratio of stresses? The 40% of smys is just a check. If so, it's been properly tested per B31.3 after the hydro, and the pneumatic test proposed is merely a leak test for the flanged joints and valves. If not, sorry- you need to go to 110% of design (relief) pressure with your pneumatic test, or do the hydro at a higher pressure.