seam welded pipe for pressure service 3

[Rjeffery]

At what size (NPS) is seam welded pipe for pressure service normally installed? (pre-1950s)

The best way to test something is to squeeze it, slowly, until it breaks!

 

[MJCronin]

Are you really asking:

"What was the maximum size for seamless piping pre-1950 ?"

I do not understank your question...

 

[JohnBreen]

Your question is not clear. Your reference to "pre-1950" is even more confusing.

Are you asking (?):

Is there a limit on the nominal pipe size for application of seam welded pipe in B31 Pressure piping systems?

Are you asking (?):

Is there a practical limit on the diameter of seamless pressure piping after which seam welded pipe (with appropriate nondestructive examination) should be specified?

What are you asking?

Please try to rephrase your question.

Regards, John

 

[rconner]

There is some brief history of steel pipe useage and design practice contained in the introductory section to AWWA Manual M11 relative to steel water pipe (I suspect there is also similar history reflected in some API, and e.g. also Steel Plate Fabricator Association/SPFA publications over the years).

 

[Rjeffery]

Sorry about the confusion.

I know that today seamless pipe up yo 20 inches in diameter can be procured, but larger than that pipe is rolled and a longitudinal weld seam is formed. piping larger than 30-35 inches may have 2 seams.

I am to evaluate piping that may be 60-80 years old which carries building service steam. Can I expect to see seam welds in piping as small as 12 to 14 inches? "What is the minimum size that I can expect to find seam welds?" is the question I should have asked...

The best way to test something is to squeeze it, slowly, until it breaks!

 

[JohnBreen]

Rjeffery

It could go either way as seamless pipe has been made for quite some time. As an expedient you could assume that there is a single longitudinal seam weld.

What is the pipe material and what is the temperature and pressure? What kind of assessment are you going to perform? With steam pipe that old you may have asbestos insulation so be careful. Check out the spring hangers too.

You got us curious now

John

 

[Rjeffery]

I am aware of the type and qty of the insulation... Thanks for the warning though. Any thing installed after 1973 should be asbestos free, but check anyway as a rule of thumb. I do not have any information as to the pipe composition other than it not cast! The max pressure is 200 psi (makes it saturated steam) the temperature has not been provided but a quick calc would determine that. only 5-10 miles of various size pipe to inspect...

The best way to test something is to squeeze it, slowly, until it breaks!

 

[metengr]

Rjeffery;

Why don't you strip a 360 degree local band of insulation and visually check for seam weld(s)? This is easy enough to do under an asbestos abatement program, and will help in your evaluation of the pipe condition.

 

[Rjeffery]

Metengr,
Piping to be assessed ranges in size from 1/2 inch to 54 inches. I know the smaller sizes are socket welds or butt welds and are seamless. The request is that an assessment of 100% the seam welds be made. I am trying to get a handle on the labor estimate to do the NDE.

The best way to test something is to squeeze it, slowly, until it breaks!

 

[metengr]

Rjeffery;
No problem. Select a sampling of the various sized steam lines (start with the 16 to 24" range)and strip a band of insulation to expose the OD surface. If you find a seam weld in this range of pipe diameters, one could assume the larger diameter piping would also be fabricated of rolled and welded plate.

 

[JohnBreen]

Rjeffery

You WILL have to get a material identification if for no other reason to make a calibration block. Someone is going to have to do a FFS evaluation and knowing the allowable stresses for ALL THE PIPING material will have to be a part of that. Positive material identification will be critical.

I have found that the best way to efficiently examine seam welds in great amounts of piping is the Time of Flight Defraction (ToFD) methodology. Go to this Internet site and watch the vidio:

http://www.vsonomatic.com/index.php?page=products_services&objectid=278#

Nothing commercial here I have no ties to ToFD except I have seen it save a lot of money and do a good job with seam weld examinations in seam welded Hot Reheat Steam Piping systems.

John.

 

[stanweld]

In those old buildings, you could have seam welded pipe almost anywhere and of any size depending on the building codes in effect at that time and jurisdiction location. If you can research the original building plans, it would prove useful. Otherwise select various size lines as metengr suggested. Understand that the original seams may not have been subject to NDE. Even if they had been, they will not meet todays RT acceptance requirements. I've performed a number of tests of 1940's to early 1950's era pipe and the long seams could not meet todays RT or UT or ET standards. You will need to evaluate based on corrosion damage and operating pressure conditions vs specified minimum tensile/yield strength of the pipe.

 

[RossABQ]

I ran several NDT programs on utility steam-electric plants built in the early '60's, 1050 psig boiler conditions. There was seam-welded piping everywhere, in sizes down to at least 8" in alloy steel steam lines. Much of the smaller Sch 80 - Sch 160 steam and condensate piping was found to be seamed. We found severe corrosion and cracking along the seams in the condensate lines (driplegs in particular) where the seams were near the bottom of the lines. These were plants that were cycled daily (and were not designed for that). After many years of service, it can be very hard to find the seams from visual inspection.

 

[MJCronin]

RossABQ.....

It sounds like you have a lot of practical/field experience to share with regard to piping inspection and older plants.

Is there any book/report/guideline on the inspection of old utility plant systems that has been developed that you could point us toward ?

Anything on the internet..?

Everyting I have found has been on the order of anecdotes, memories and snippets from reports.

-MJC

 

[RossABQ]

MJC, I was doing these tests as an extension of a testing program that was mandated in the mid-'80's when several catastrophic failures of seam-welded P11 Hot Reheat lines had occured. I remember there being a ton of articles in the ASME magazines, POWER magazine, and various seminiars I attended back then. This was pre-internet, but I'm sure a lot of the info would be on the 'net now. I'd suggest searching on "P11 seam weld crack NDT" and similar keywords. I don't know of any texts that addressed the problems and testing directly. One of the stations that blew a line was the Navajo Station as I recall, might try searching on that too. Note that this problem was fairly specific to power plants, but the NDT programs and methods are universal to a large degree.

 

[stanweld]

Rjeffery,
Would your investigation have anything to do with the catostrophic failure of an underground steam heating line in Manhattan? If so good luck!! As I stated before, you will find continuous butt welded pipe [forge welded], ERW pipe, flash welded pipe [AO Smith] and electric fusion welded pipe and some seamless pipe. Many of the circ seams will have been made with the Oxy-fuel gas welding process.

 

[stanweld]

Rjeffery,
Regarding asbestos insulation and 1973. Until about 1976 many Owners/Engineers/Architects and US GOV were still specifying asbestos. The Engineering company for which I worked, specifed asbestos in 1973 and 1974 but by 1976 refused to specify for all owners other than the US GOV. Finally, in late 1978, it refused to specify asbestos for US GOV work. Some of the US GOV specs requiring asbestos were still issued after 1981.

 

[Rjeffery]

stanweld, My project is NOT in NYC.

And the rule of thimb for us is... "Test it!" Even if it is yellow or pink. there is such a mix out there that one can not be sure.

As you have pointed out, the year of manufacture is no assurance that it is NOT asbestos.

The best way to test something is to squeeze it, slowly, until it breaks!