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I'm working for a company now that's looking to get certified for ABS welding and needs me to take a 6inch schedule 80 6g test but this backing ring is throwing me off. I had one test plate come back with slag in the root but I cleaned the piss out of it with a grinder and wire wheel. I'm wondering if slag was trapped in the 32nd gap between the backing ring and the inside of the pipe? Anyone with experience on this test have any tips on keeping the root clean? I can use 1/8 electrode or 3/32 but it has to be 7018 the whole way out I was using 3/32 7018 on about 80 amps with a slight weave to join both bevelsHere's photos of my root and finished product
Reply:for me, 3/32 80 amps would be a lil low on somthing that thick. maybe hotter will let u move faster to keep away from all that slag, and less fill . also i think the extra heat would help out w/ that problem in couple diff ways. looks real good thoughLast edited by 123weld; 06-26-2021 at 08:15 PM.
Reply:Well first of all your chill ring should have a split in it . Try to put the split on top the there should be spacing nubs / pins on your ring most of the time they are 3/16 wide . I always carried ice pics on the truck pushed them in the split till the ring was up tight against the pipe walls tack it in four places tack it both sides of ice pick clean it with wire wheel weld split shut first grind it clean . I am guessing your going uphill ? If I could get away with it I would put one quick pass downhill with 5P+ grind and buff smooth get some 3/32 and go to work that first pass you have to move right along so don’t turn it down and try to fill it cause you will burn a hole in it gets quick pass in there then start filling. You have a real fine edge there so if you burn through you will leave a slag inclusion . If you put a big land on them you will have trouble getting the land fused to ring after you get the first one it gets easier .
Reply:the backing ring can pretty easily shrink or warp as you run your root causing a gap to form between the backing ring and the pipe, I find the best way to get around this is to have MANY small tacks every inch or so around the root, if this is permitted by the WPS. You need to get the ring to be a very tight fit inside the pipe, I carry a wedge made of 3/32 thick 253MA stainless for exactly this, do as Leogl said to get the ring tight inside the pipe. Both pieces of pipe also have to be EXACTLY the same ID otherwise you'll end up with a gap on one that will trap slag, measure the ID circumference of both pipes and match bore them to within 1/32nd or less, the smaller the pipe, the closer the tolerance has to be.I have to say backing ring welding of pipe really is a bad idea, for x ray spec its way slower than just doing an open root with 6010, even 7016 is faster once you consider the prep time to get the backing ring fitted, or TIG if they don't want slag left in the pipe will still be faster and easier.The only situation I've ever seen backing ring's used for pipe that actually made sense was on stainless lines that couldn't be dammed for a purge and that was unsuitable for soluble dam's with a pin purge because of process contamination.
Reply:
Originally Posted by 123weld
for me, 3/32 80 amps would be a lil low on somthing that thick. maybe hotter will let u move faster to keep away from all that slag, and less fill . also i think the extra heat would help out w/ that problem in couple diff ways. looks real good though
Reply:
Originally Posted by ttoks
the backing ring can pretty easily shrink or warp as you run your root causing a gap to form between the backing ring and the pipe, I find the best way to get around this is to have MANY small tacks every inch or so around the root, if this is permitted by the WPS. You need to get the ring to be a very tight fit inside the pipe, I carry a wedge made of 3/32 thick 253MA stainless for exactly this, do as Leogl said to get the ring tight inside the pipe. Both pieces of pipe also have to be EXACTLY the same ID otherwise you'll end up with a gap on one that will trap slag, measure the ID circumference of both pipes and match bore them to within 1/32nd or less, the smaller the pipe, the closer the tolerance has to be.I have to say backing ring welding of pipe really is a bad idea, for x ray spec its way slower than just doing an open root with 6010, even 7016 is faster once you consider the prep time to get the backing ring fitted, or TIG if they don't want slag left in the pipe will still be faster and easier.The only situation I've ever seen backing ring's used for pipe that actually made sense was on stainless lines that couldn't be dammed for a purge and that was unsuitable for soluble dam's with a pin purge because of process contamination.
Reply:
Originally Posted by Jsmith98
The chill ring is pretty tight where the split is, I tried to put I a pick or a flat head and split it to no luck. I have to use c clamps or vice grips to squeeze it down which kind of is a pain. I'll measure the ID on Monday. Also the WPS calls for 4 tacks on the inside of the pipe. Not on the root face...which is odd to meHonestly I'd much rather do a tig root and 7018 all the way out. But for ABS this will qualify me for all position plate and pipe all positions for structural repairs according to our QAIm the only welder at this company so I've been figuring out this welding part on my own really |
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发表于 2021-9-1 23:16:14