ISO drawing dimensions

  • jhsunny2009
  • jhsunny2009's Avatar Topic Author
  • Offline
  • New Member
  • New Member
More
10 years 9 months ago - 10 years 9 months ago #8315 by jhsunny2009
ISO drawing dimensions was created by jhsunny2009
Do we have to ensure the dimensions on ISO drawing is even? for example, from equipment nozzle to elbow should be 2300mm instead of 2297mm; control valve station from one elbow to another elbow should be 4200mm instead of 4186mm?

Please Log in or Create an account to join the conversation.

More
10 years 9 months ago - 10 years 9 months ago #6834 by Jop
Replied by Jop on topic Re: ISO drawing dimensions
You wrote: "Do we have to ensure the dimensions on ISO drawing is even?"

In general the answer is NO! But don't be ridiculous about it.
Remember the pipe fab shop and the field need to build it. Don't make them mad with ridiculous numbers that are difficult to find on a measuring scale.
- the dimensions for fitting make-up is what it is
- the dimensions for all non-fitting make-up assemblies can be rounded off

Do it once and Do it Right

Please Log in or Create an account to join the conversation.

  • jhsunny2009
  • jhsunny2009's Avatar Topic Author
  • Offline
  • New Member
  • New Member
More
10 years 9 months ago - 10 years 9 months ago #6835 by jhsunny2009
Replied by jhsunny2009 on topic Re: ISO drawing dimensions
thanks Jop.

usually I put round number on non-fitting component such as pipe, but this make iso overal dimension is odd. one of senior designer in my team thinks we have to keep the overall dimension even (say control station width) instead of pipe length even.

another one is what is the actual length in the fab? is the fab pipe length is exact same as pipe length in model,say pipe length is 2000mm.
in the fab and construction, people more concern overal dimension or each single component dimension?

Please Log in or Create an account to join the conversation.

More
10 years 9 months ago - 10 years 9 months ago #6836 by Jop
Replied by Jop on topic Re: ISO drawing dimensions
jhsunny,
You wrote (italics):
A. "Usually I put round number on non-fitting component such as pipe, but this make iso overall dimension is odd."
No, this is not the way to do it.

B. "One of senior designer in my team thinks we have to keep the overall dimension even (say control station width) instead of pipe length even."
Yes, this is the better way.

C. "Another one is what is the actual length (of the pipe) in the fab?"
The actual length of the pipe in fabrication is what it is. The shop knows how to make your overall dimension come out right.

D. "Is the fab pipe length is exact same as pipe length in model, say pipe length is 2000mm."
Possible not but you do not need to worry about that. You only need to worry about the overall.

E. "In the fab and construction, are the people more concerned about overall dimensions or each single component dimension?"
The overall.

At this point you may want to know the basis for my advice.
(a). I was in the piping profession for more than 45 years from entry level designer to Piping Department Manager.
(b). During my years in the Piping Profession I also spent a few years as an Engineering Manager in a pipe fabrication shop.
(c). The dimensions for fittings you have in your data base and in fitting catalogs are averages of fittings which are subject to dimensional tolerances. They are not always the same from the same manufacturer or from one manufacturer to another.

Do it once and Do it Right

Please Log in or Create an account to join the conversation.

Moderators: Jop
Time to create page: 0.221 seconds