Welding on a pipe filled with cold water
Welding on a pipe filled with cold water
(OP)
Is it possible to achieve a weld on the outside surface of 36" diameter 1/2" thick pipe while it is filled with water?
Thank you
Thank you
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Welding on a pipe filled with cold water
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Welding on a pipe filled with cold waterWelding on a pipe filled with cold water(OP)
Is it possible to achieve a weld on the outside surface of 36" diameter 1/2" thick pipe while it is filled with water?
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RE: Welding on a pipe filled with cold water
RE: Welding on a pipe filled with cold water
The water may turn to steam and blow your head off.
RE: Welding on a pipe filled with cold water
But it will suck the heat out of the weld zone far faster than the welder can put heat in.
The result will be lack of penetration and fusion and a bad weld.
RE: Welding on a pipe filled with cold water
1. Is the water moving or stagnant?
2. How big of a weld are you asking about? I would guess that it is not the full circumference of the 36" diameter pipe?
RE: Welding on a pipe filled with cold water
I was envisioning a smaller pipe, but it doesn't sound like a good idea regardless. Whether it bursts immediately or produces a poor weld from lack of heat (possibly bursting later), it is almost certainly a bad idea. The right thing to do is to drain the pipe.
RE: Welding on a pipe filled with cold water
Thank you all
RE: Welding on a pipe filled with cold water
RE: Welding on a pipe filled with cold water
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: Welding on a pipe filled with cold water
THE WELD WILL CONNECT A BRKT TO RESIST APPROX 40 K OF THRUST FORCE AT ABOUT 6 TO 8 ECCENTRICITY (240 K-IN TO 320 K0-IN MOMENT)
RE: Welding on a pipe filled with cold water
RE: Welding on a pipe filled with cold water
RE: Welding on a pipe filled with cold water
Welding procedures can readily be developed and implemented to make the weld safely and to produce a sound, reliable joint. You will need to determine remaining thickness of the pipe at the proposed connection(s). It is assumed that you know the specification/grade of the pipe.
RE: Welding on a pipe filled with cold water
It is workable, just as stanweld and others have noted. Proper procedures. No different than welding cold steel in the winter.
RE: Welding on a pipe filled with cold water
rmw
RE: Welding on a pipe filled with cold water
RE: Welding on a pipe filled with cold water
Test loop information as well as welding procedure qualification guidance can be found in API 1104 Appendix B. The caution is that heat input calculations based upon flow conditions will need to be performed prior to actual production welding to insure that the weld can be properly made.
RE: Welding on a pipe filled with cold water
RE: Welding on a pipe filled with cold water
We are assuming that your pipe is carbon or alloy steel and not ductile iron or lined steel (depends on liner).
RE: Welding on a pipe filled with cold water
RE: Welding on a pipe filled with cold water
A sewer pipe has essentially no pressure load to fatigue the weld, so based on the comments above you're probably fine as long as you understand the loading and the are able to quantify the degraded strength of the weld.
RE: Welding on a pipe filled with cold water
RE: Welding on a pipe filled with cold water
Bo
RE: Welding on a pipe filled with cold water
If the pipe is low carbon steel the results should be acceptable, but as the carbon equivalence increases, the hardness of the heat affected zone will increase from the rapid absorption of heat by the water which will result in increased amounts of martensite.
You can minimize the amount of untempered martensite in the HAZ by using a butter layer technique. The technique employs a layer of low hydrogen weld deposit on the 36 inch pipe as the first step. The actual weld deposited to join the members is deposited in a manner that will temper the HAZ of the initial weld beads deposited, i.e., the butter layer. It is imperative that the last weld beads deposited do not impinge directly on the wall of the 36 inch pipe to prevent the formation of untempered martensite once again in the 1/2 thick base metal.
Best regards - Al
RE: Welding on a pipe filled with cold water
RE: Welding on a pipe filled with cold water
You only have [filthy] water. Just ensure that pressure cannot accumulate.
Then conduct a Ultrasound survey of the proposed weld location to ensure sound metal thick enough to be weldable. I use 3/16" for a minimum.
Weld using E7018 electrodes ONLY. The celoustic rods that Eddycurrentguy warned against are 6010 and a few others. Use 7018 only. Stay with 3/32" diameter rods to control the heat input, even though it takes a little longer to finish.
That's it! Again, this is well-tested, and documented in API.
RE: Welding on a pipe filled with cold water
The butering technique suggested by GTAW is a great one...can be labor intensive, but, if properly applied, is well worth the efforts.
For in-service welding, I suggest the wall thickness be 0.250" minimum....thats the standard that several pipeline companies have used in the past, althought the material grade, OD, and flow conditions will need to be factored as well...