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Up Topic Welding Industry / General Welding Discussion / Question about roof top gas pipe
- - By Cumminsguy71 (*****) Date 12-01-2011 01:27
Quick question, been doing a bit of roof top work lately. I've had to tie into some pre-existing stuff and from the looks it has been up there for awhile. Now, it's pretty simple to figure out why they have coated pipe in the ground but all the stuff I've seen done on roof tops is bought, put up, welded and then left on wood blocks. They don't even go back and paint the welds, just bare.

Question<  Why is that? I've been on a bunch of roof tops for other reasons and it's all the same. Maybe it's just around here but seems like I saw some in Atlanta that was the same way. The plumber and I were talking about that today, he had a bunch of screw pipe where he was at that looked like they recommissioned it from the Ark! We both wondered why they did not use coated pipe. A bit more costly but junk would last forever on a roof top!

Just a curious,

Shawn
Parent - - By Superflux (****) Date 12-01-2011 04:29
Because they are a bunch of Turd Herders that don't have enough sense to not bite their fingernails when snaking a sewer line.
From my experiences in the Commercial world, there are very few engineered pipe hangers. Most of the drawings only have details for the mechanical rooms. The rest of the pipe seems to be "field run" and left at the discretion of the plumber. Like you, I was just the welder and rarely saw a print.
"There's the new gas line and meter coming up out of the ground." 15 minutes later after walking through the hospital E.R., and a peek into the attic over the Chapel, past ICU, CCU, we get to the new Boiler. "Yeah and it ties in Here". "Oh, by the way.... can you not grind? Admin asked us to keep the noise to a minimum." "Don't worry, there's no X-ray."
Parent - - By Cumminsguy71 (*****) Date 12-01-2011 12:48
That's funny! And good to hear! I'm actually looking at a job and the mechanical has prints and that's it, just a rectangle with a small rectangle for the boiler, two circles, one for the expansion tank, one for the air seperator and two more small rectangles for the pumps and then a bunch of lines for pipe. Only detail is a few pages later that shows the end of the pump with with a flex pipe, triple duty valve and that's it. No measurements on where they want this set or anything, just a step above what my kid could have drawn! Guy wants a hard price instead of "by the hour". Have not even seen the actual jobsite. He figures the mechanical room can be built out in 6 days, mind you the mechanical room is EMPTY at this point and we would be installing EVERYTHING. A friend of mine and I think his 6 days is a bit of a stretch! Piping to the tower, piping inside the building, probably in the ceiling(6" pipe by the way).

It's weird, you look at a drawing for sprinkler pipe and they've got exact cut measurements!! We talked yesterday and it's still gas pipe on the roof and when it rusts thru and nobody knows and it starts to spew gas everywhere then what? Underground gas and above ground gas pipe are like polar opposites! In the ground, code, coatings, blah, blah, blah. Above ground....cue Benny Hill music!!!

Like I said, glad to hear it's not just us around here with the hideous prints for a mechanical room! Not grind!! Hahaha!!!
Parent - - By Sberry (***) Date 12-03-2011 15:00
In the ground, code, coatings, blah, blah, blah. Above ground....cue Benny Hill music!!!

Are we not talking about 2 different sets of working pressures here?
Parent - - By Cumminsguy71 (*****) Date 12-03-2011 23:38
Not necessarily, what type of pressure feeds a home? If your talking transmission lines at 750psi then yeah but not all lines are that high. Have worked on some feeding some residential areas that are barely 50psi. Actually we did a regulator station that kicked it from 750 to 55 to run into some 4 inch that was feeding some houses. Besides that it's still pressurized, rusting freely. My point was simply how I don't understand such heavy regs on underground, bedding, high tech coatings and so forth while all of our malls, shopping centers, home stores etc., have bare pipe all over the roofs. Any techinical difficulties, inspections are left up to the maintenance guy....if he's actually taking his job seriously. Was just curious if anybody had any insight or intimate knowledge on why this is.
Parent - By Tommyjoking (****) Date 12-04-2011 00:10
$$$ the stuff in the ground is the utilities responsibility...cost money to dig up and replace.  They basically don't care a whole lot except for PR where it is on the customers dime/head.
Parent - - By Northweldor (***) Date 12-04-2011 00:14
I think the pressure in a residence after the regulator is actually measured in ounces per sq. in. but is possibly higher in commercial buildings due to longer runs.
Parent - - By Cumminsguy71 (*****) Date 12-04-2011 01:02
Guess I need to rephrase something, said I don't understand the regs for underground. I do, makes sense but just seems like polar opposites when you consider roof top and in ground.
Parent - - By Tommyjoking (****) Date 12-04-2011 01:19 Edited 12-04-2011 01:23
well it is still kinda the same answer,,,,$$ drives the regs, liability, insurance, lawyers etc.   But yeah I see where your coming from, the lack of attention is a future hazard to say the least.  Think about all those big malls, mains going thru the foundation but...oh wait an expansion well we could easily pull up to the roof and across and spend a whole lot less....no less people in danger from the lack of attention....but no codes stopping us.   Maybe the pipe typically outlasts the buildings...or maybe just not enough deaths to force change.  Heck I have to force the gas company to do leak checks on my house on a reconnection! Seems like they are way more worried about sewer and water connections then gas....maybe cause the gas is mostly commercial taking care of itself.  Water always involves a municipality (govt) in some sense...the gas company is kinda like a self regulated cowboy.  I am way more worried about gas leaks then some turds going off the reservation.  I dunno man.  20 years ago people hardly paid any attention to stairs, landings and railings....now there are enough codes to make you get dizzy in most jurisdictions.  Took a lot of lawsuits to get there. Thanks for the heads up on some of that stuff btw.

Hope all is good with ya up there bud.  Thought you were gonna finish the bigger rail job and layout the rest of the year? I figure you have earned the break.
Parent - By Cumminsguy71 (*****) Date 12-04-2011 01:30
Yeah, guess that's my point, lack of attention as you said on the roof top stuff. The hospital I did a few days ago was screw pipe on the roof and it was rusted something fierce! I mean pitted rusty and that was the second roof top job in about a week that had pipe like that. I just stood up there and looked at the pipe and said to myself, "hmmm??".

Doing good up here, sorry I missed ya today. Was under the truck pulling Dodge's "fix" for my fuel pump(in tank conversion). Converted back to original and installing a warranty mechanical pump. Been trying to ease off the last bit of the year but it just won't quit! Can't complain about that though. Still got the big rail job to complete, 50 feet and I'm done for the year!!! Got all my pieces rolled and ready to go, just looking for a couple days of good weather. Takes about 2 days to build one and then shoot it to powder then 1/2 day install. Figure a good solid 4 days to build, then 4 days to powder both and a day to install, weather permitting of course!
Parent - - By DaveBoyer (*****) Date 12-04-2011 04:00
As far as I know, it is measured in inches of water, 11" WC being pretty common. That translates to about 1/2 PSIG.
Parent - By Cumminsguy71 (*****) Date 12-04-2011 15:31
As far as psi sounds about right. Some commercial buildings I've worked in were 2psi max coming in.
Up Topic Welding Industry / General Welding Discussion / Question about roof top gas pipe

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