Pex Piping - Plumbing - DIY Home Improvement | DIYChatroom

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Plumbing


Thread Tools Display Modes
Old 06-18-2010, 06:35 AM   #1
Join Date: Jun 2010
Posts: 1
Rewards Points: 10

pex piping

how do you size pex piping, when installed in a traditional method like a copper system which incorporates tees for branch connections?

..some manufacturers reference the Uniorm Plumbing code or national plumbing codes but some do not make a reference....they recommend the Home Run method.


wallport is offline   Reply With Quote
Old 06-18-2010, 06:55 AM   #2
Join Date: May 2010
Location: Massachusetts
Posts: 133
Rewards Points: 75

Its sized pretty much the same way copper is sized, based on fixture unit counts and how many fixtures each leg of the system serves. Also taken into account are distances, available pressures and elevations. The only difference between copper and pex, is the friction loss co-effiecient when determining the pressure available for friction loss.


The Engineer is offline   Reply With Quote
Old 06-18-2010, 08:15 AM   #3
Join Date: Nov 2007
Posts: 383
Rewards Points: 410

The reason copper has size limits, is because water flowing through it at high velocities wear it out and it can be very loud.

For cold water, copper pipe shouldn't have a flow of greater than 8 feet per minute and for hot water 5 feet per minute.

How that affects PEX I don't know I think it would have a different set of rules.
Piedmont is offline   Reply With Quote
Old 06-18-2010, 08:28 AM   #4
Civil Engineer
Join Date: Mar 2009
Location: Boston
Posts: 5,679
Rewards Points: 4,938

Piedmont, you need to check your units. The flow you quote would be in feet per second, not feet per minute. And copper can certainly handle more than 8 feet per second, its simply that at higher velocities you get greater pressure loss in the pipe, and hence lower pressure at the fixture. Standard tables for copper pipe typically show losses up to 25 feet per second for applications where pressure loss is not significant.
Daniel Holzman is online now   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
exterior piping for Nat gas rcassidy Plumbing 3 03-16-2010 06:32 AM
Piping Layout for New Bathroom structman Plumbing 2 02-23-2010 05:24 PM
Copper Or Iron Piping? beatboy77 Kitchen & Bath Remodeling 2 01-03-2009 12:36 PM
How would I fix/re-do my sink's drain <leaking> piping? joeyboy Plumbing 17 12-18-2007 05:23 PM
PVC piping allowed in NY? honeydew Plumbing 6 11-21-2007 06:57 AM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1