Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations KootK on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Pipe Terminology 3

Status
Not open for further replies.

sportsnut44

Civil/Environmental
Nov 20, 2008
20
In a potable water system, say a 12" watermain, what is the correct way to refer to a short piece of pipe, say between fitting, etc. Pipe spool is something that is made in the factory to a specified length, but I'm talking about something that is likely going to be fabricated / cut in the field for fit-up. I don't believe a "nipple" is correct either for something like a 12" dia DIP. Is there an industry standard for a short piece of field fabricated piece of pipe required to fit up a particular connection or assembly? Thank you.
 
Replies continue below

Recommended for you

Generally it's called a "pup piece".

No idea why but that's what everyone calls it!

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
There is no strict definition on when a pup piece just becomes a piece of pipe or header pipe, but as a guide anything beyond about 3D would likely just be called pipe.

Especially if it's cut to fit on site and less than about 3D in length it magically becomes a "pup piece"...

Don't get anyone started on the minimum distance argument - this has been examined many many times on this site - just do a search on "minimum distance welds"....



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Whether you call it a pup or a spool piece depends on who you are talking with, whether it's an engineer or a welder in the field.

A pup piece is a very short length of pipe in a welded piping system which is eventually welded into the pipe segment. Typically less than 6-Inch long although there are no defined rules.

Ductile iron piping is generally not welded, but may be in some circumstances. However, it is not practical to weld a very short length of ductile iron pipe.

For ductile iron water mains, pipe spool is probably more appropriate terminology.

 
in general, on water main projects (buried, bell and spigot, ductile iron pipe) I have not seen plans refer to any field cut pieces as either spools or pups. The note "cut to fit" or "field cut to fit" should be adequate
 
PUP PIECE is usually this is described as. In my opinion if you are inserting a piece of pipe as a "fill in" in the field to make up the length or for any such reason, it is pup piece. These kind of pieces are usually from : to couple of ft max
 
"These kind of pieces are usually from : to couple of ft max"

Although there is no strict rule for defining a "pup" piece, anything over 1'-0" in length is no longer considered a "pup" piece. It is simply a piece of pipe. The OP is correct in assuming that a short piece of pipe on a 12" diameter line is not a nipple. A nipple is used in threaded or socket welded connections but is still generally limited to 1'-0" or less.

"Pup" is the correct terminology for a short piece of butt welded piping.

This topic has been brought up many times in the past. Do a forum search on "pup pipe" or "pup piece of pipe" and read some of the past threads.

"Tell me and I forget. Teach me and I remember. Involve me and I learn."

- Benjamin Franklin
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor