Building Piping - Pipe Support Location Drawings 2D - Hangers, Rods, Clamps etc 1

[btalon]

Hello everyone,

I am stepping out of Oil and Gas and into Water. Long story short, I know pipe stress and supporting on racks etc from the Oil and Gas, but switching to water, I am now on B31.1 code and the use of hangers, rods, trapezes, etc.

I can fundamentally perform the stress analysis no problem, but my question is the project I am on is all 2D. There are no Isometrics being generated. It seems in this industry, a lot more is transferred to the mechanical contractor during construction.

I really hate these 2D drawings and I am trying to think the best way to communicate to the contractor pipe support locations and type, but 2D drawings is just annoying.

I am taking a step back and thinking maybe this is not how this is done in this industry? It seems most projects I have looked at which are similar just spell out general spacing guidelines for span of hangers etc and I assuming resident engineers during the construction phase (not detailed design) ensure the pipe is properly supported.

We are using Autodesk MEP for the drawings (not REVIT), so there is no database derived MTO's or isometrics from 3D or anything.

Are the working of piping drawing just different in this industry? What am I missing?

2D drawings for piping plans, piping support location drawings, instrument location drawings etc just seems stone age.


Can someone explain what the general process is for piping drawings in Detailed Design and Construction for this type of industry?


Appreciated.

 

[pennpiper]

btalon,
Please remember, 2D Drawing package not only includes piping plans, piping support location drawings, instrument location drawings etc but it normally also includes Sections. Piping Plan cannot ever tell the whole story. If you do not have Piping Isometrics, then you need the section drawings.

Your comment- "It seems in this industry, a lot more is transferred to the mechanical contractor during construction."
The Water processing industry is not the only ones that do "Cheap" Design Engineering and then end up paying inflated costs for shoddy work at high rates by the Installation Contractor.

Sometimes its possible to do all the right things and still get bad results

 

[btalon]

Thx pennpiper.

It just seems so "half a$$" in some ways. I am reading on sections drawings now and it seems there will be so many them needed, why these industries still use 2D is beyond me. This is just OLD SCHOOL.

Calling out all this stuff, and them modeling in Caesar II. Sheesh. I would rather cut Stress Isometrics form Caesar II and issue those IFC.

Can anyone share any "war stories" on how this 2D process works and lessons learned as they transitioned into construction?

 

[Gator]

Are there centerline or bottom of pipe elevations noted on the piping plans? I don't see how anyone can further detail, generate Caesar files or build anything if there aren't.

Is the piping welded, Victaulic or threaded? What piping sizes? What you're describing sounds like old-style drawings for plumbing or perhaps building sprinkler piping.

 

[btalon]

I am gutting and re-installing new power generators and piping in a waste heat recovery system. Quite a large job. Everything is ASME b31.1 flanged steel piping. Not much will be threaded.

The drawings are only piping plans for now. The contractor is procuring all the equipment besides the generators and heat exchanger skids pump skids. Contractor is getting the air handler units, chillers, pipe, valves, pumps etc.

I wont even know nozzle locations for those pumps until construction procurement phase! FML.

The drawings are all being done from scratch from existing 2D drawings of the power house building.

 

[Gator]

All you can really do is get quotes for fabrication and erection, as far as I'm concerned. If you're lucky the newly-purchased equipment will match the old for the critical connections and dimensions. The few times I've been involved in similar work this hasn't been the case, so I wish you luck.

 

[bimr]

Regarding:

"assuming resident engineers during the construction phase (not detailed design) ensure the pipe is properly supported"

That would be a mistaken assumption as the resident engineers by Contract are not supposed to be making any decisions. The resident engineers are only supposed to be documenting the construction and this is spelled out in the Contract. It is also a mistake to assume that the Contractor knows what he is doing.

What does need to be shown on the drawings (cartoons if you will) are special details that the Contractor may not typically be aware of.

In regards to stress analysis, stress analysis is not common in the water business as most of the work does not require it (low velocities, moderate temperatures, etc.).

 

[PEDARRIN2]

Sounds like it might be a small cogen system where electricity and heat is produced.

The ones I am familiar with are designed as part of a building system which would be B31.9.

If so, two dimensional drawings with sections would be appropriate - although depending on the drafting software, isometrics can be produced.

These designs do allow for some leeway with the installation which those who are more familiar with more rigorous designs might find "half a$$". But if the design is done correctly, isometrics are not always required.

 

[btalon]

The size of the facility I am working on is about 6 Mega-Watts. Not super huge, but not exactly tiny either.

It is definitely B31.1.

BIMR, thanks for the clarification of the frequency of stress analysis. I am thinking the same thing. However, I am always curious about nozzle checks on pumps and heat exchangers etc. Improperly supported pipe can be bad for this and just ignoring it feels uncomfortable for me.

Can anyone comment if they even produce pipe support location drawings for these types of projects or just specify pipe spans?

 

[europipe]

I like it that way, draw by hand, it is done with more companies that You seem to know.
Especially when You also can do the supervision at site.
Learn to meddle at site, try to get there. nice