passing x-ray. please help

By blrrat4200 Date 07-28-2007 21:43

hey guys, i need some advice. i need to know some basics, pipe test in 6-g position on 2 1/2 extra heavy wall ,ive got to put in 1/8 6010 root & finish with 3/32 7018.please give advice on proper procedure as to where to start &stop. i'm guessing at 6:00 & run vertical back to 12:00, or should 6010 be run downhill , i can do both but i'm trying to pass an x- ray for the first time . iv'e got 3 test coupons & acouple days to work the bugs out. sure would appreciate some wisdom on where my start & stop points should be &any tid bits about passing an x-ray test ? do i grind all staarts & stops i even thought about taking a long neck grinder & grinding inside the root pass to make it apear clean ; but i reckon thats cheating , please give advice blrrat&aol.com

By fbrieden (***)

Date 07-28-2007 22:49

Check the WPS.

By swsweld (****)

Date 07-28-2007 22:57 Edited 07-29-2007 00:00

Weld progression is stated on the WPS that you are testing to. Normally uphill. Pipeliners downhill.
Yes you should start at 6 and end at 12. Usually four tacks. Feather all tacks, especially your starts. Makes it easier to tie into. Don't set gap too tight or you will not get the penetration you need to pass xray. Most testing supervisors will not allow grinding on the I D. Get a good fit. A little hi-lo on the fit-up can cause internal undercut. Make sure you get some penetration on the ID(1/16 is ideal) Grind the root pass thoroughly to remove most slag, undercut, irregularities, etc. Do not grind so much that you will burn through on the hot pass. Fine line there. I put my hot pass in with 3/32 7018s some people use 6010 on the hot pass. If you use 7018 grind your start at 6 before you start up the other side. After the hot pass I run fairly hot but not too hot. Remove slag completely every pass, remove porosity if you get any, avoid undercut, fill out completely (you can bust out for underfill on the cap) arc strikes only in the groove, if you cap with stringers overlap them more than 50%, do not leave valleys between beads. Plan your bead placement, don't leave a sharp corners at the toe of the welds it will trap slag, try to fill coupon just below flush before you cap it.

I do not grind all starts and stops throughout the test, shouldn't have too. Just chip the slag at the stop before you restart the next rod. If you grind too much the tester might question your ability. I've taken test with only a file no grinder after he accepts fit-up.
Remember xray sees almost everything. If you can see it, remove it. Check with the test shop supervisor to see what he allows and does not allow, (grinding,hot pass rod, ? much penetration)Try to stay calm, keep it clean and good luck. Let us know how it turns out.

By welder5354 (**)

Date 07-30-2007 03:16

Swsweld has explained it very well. One thing that we do differently at out training centre is the tacking method. We prefer one bridge tack @ 9 and another bridge tack @ 2. The coupon will then be tacked in place. Start your root pass @ 6 and then progress towards 2 0'clock. Just before you get to the 2 O'clock tack; stop and remove that bridge and now u can procede to complete that side. I always like to go a little beyond 12 and stop at 11. This will help u see a little better when u come up the other side and do the last tie-in. Now go back to 6 o'clock and do the easy side; progress up that side and before u get to that bridge tack; stop and remove it. Now start again, progress towards your last tie-in, make sure u grind the root at 11, so as to make a good tie-in. Always do your hard side first.
Work hard it will pay off. Practice! Practice! and more.....