Welcome to Plbg.com
Welcome to the Popular Plumbing, Kitchen, Bath Advice Site
Special thanks to:
FAMOUS PLUMBINGSUPPLY the award winning plumbing, kitchen and bath catalog. The largest selection of plumbing products and supplies on the net with over 1,600 pages. Since 1995 the PlumbingSupply Group has been serving the entire Internet community.
www.PlumbingForum.com
THE Dynamic Plumbing, Kitchen and Bath, Information, Advice and Sharing Forum
click here to learn how to show an image on PLBG.com

Over 515,000 Posts in over 150k Threads

By far the most popular STRICTLY PLUMBING INFORMATION SHARING FORUM board on the Net. Ask any toilet, sink, faucet, pump, water quality and other plumbing related questions here. Plumbing professional and DIY tips, tricks, shortcuts, remodeling, plumbing advice forum and blog. Please refrain from asking business, pricing, legal or any other non strictly plumbing related questions. 

New TopicSearchLog In Newest Messages
 Pipe Threads IPS / NPT
Author: pbr2424 (NH)

I appear to to be confused about the difference between NPT threads and IPS threads. I have to put some ball valves on some old galvanized pipe and I assumed it was IPS threads. So you would get an IPS ball valve. But IPS means iron pipe straight thread and galvanized and black iron are tapered. Got myself confused. Any help appreciated.

Thanks
Peter

I think I figured it out myself IPS means iron pipe size where FIPS means female iron pipe size. Think I got the wrong imformation in the begining.

Thanks



Edited 2 times.

Reply To This Message

 Re: Pipe Threads IPS / NPT
Author: SMSPlumbing (PA)

Glad we could help :)

Reply To This Message

 Re: Pipe Threads IPS / NPT
Author: clarkkent1987robs (Non-US)

Quote

I appear to to be confused about the difference between NPT threads and IPS threads. I have to put some ball valves on some old galvanized pipe and I assumed it was IPS threads. So you would get an IPS ball valve. But IPS means iron pipe straight thread and galvanized and black iron are tapered. Got myself confused. Any help appreciated.

Just to make it clear National Pipe Tapered Thread (NPT) is a US standard for tapered threads used on threaded pipes and fittings. NPT compatibility examples are Male NPT also known as Male Pipe Thread (MPT) and Female NPT also known as Female Pipe Thread (FPT). And an IPS is an abbreviation of Iron Pipe Straight Thread which is the Generic Name for Straight Pipe Thread (NPSH). NPT and NPS/IPS are the pipe thread standards.

[@#$%&[emergencyplumbergeelong.com.au]]plumber geelong[/url]

Reply To This Message

 Re: Pipe Threads IPS / NPT
Author: hj

quote; And an IPS is an abbreviation of Iron Pipe Straight Thread which is the Generic Name for Straight Pipe

Here I have been using IPS for 60+ years as an abbreviation for EVERYTHING with a thread in, or on, it, and NOW you tell me that I have been wrong.

Reply To This Message

 Re: Pipe Threads IPS / NPT
Author: packy

i'm curious ???
would a left handed nipple/coupling be considered IPS?
as far as i know, the thread pitch and threads per inch are the same as right handed threads, they just go the other way.
so, in the definition of IPS, does it state "turn clockwise to tighten"?

Reply To This Message

 Re: Pipe Threads IPS / NPT
Author: hj

No, it would define the thread pitch and and the specifications for the cut, but not the direction, since it would be for an "infinitely narrow" part of the thread so direction would not be a factor. And as for a "straight thread", electricians are the only ones I know who use them.

Reply To This Message

 Re: Pipe Threads IPS / NPT
Author: asktom (MT)

I seem to recall there was a piping system that used straight threads and locknuts. You screwed the pipe into the fitting with a locknut already on the pipe, wrapped some sort of packing material between the fitting and locknut, then tightened the locknut up against the fitting. I think it was a Brit/Aussie thing. I use NPT and IPS interchangeably and have never been challenged on it, but I don't hang out with engineers.

Reply To This Message

 Re: Pipe Threads IPS / NPT
Author: hj

That was a "longscrew". It was a way to insert a fitting into a galvanized drain line, similar to the sisson joint in cast iron.

Reply To This Message

 Re: Pipe Threads IPS / NPT
Author: jimmy-o (CA)

To get very techie, I think IPS is iron pipe size, meaning the PIPE, and not bearing any actual reference to threads. NPS, NPT, etc,....those are THREADS. But the terms are thrown around rather loosely by all of us!

Reply To This Message

 Re: Pipe Threads IPS / NPT
Author: packy

besides hj, packy and Methuselah, i wonder if anyone has ever actually used a sisson joint.
i believe i have used only 2.
kaypher "Y"s and kaypher "straight"s were the only joints that were legal prior to no hub clamps.
of course there were manhoff sleeves but the were more for adapting to a galvanized pipe without threading.

Reply To This Message

 Re: Pipe Threads IPS / NPT
Author: bernabeu (SC)

IPS: iron pipe size, vague as it may be straight ('running') or tapered
by informal convention it is interpreted as tapered unless otherwise stated

NPT: national pipe tapered (same thread as IPS tapered)

NPSM: national pipe straight/standard mechanical (running or straight thread)

Reply To This Message

 Re: Pipe Threads IPS / NPT
Author: hj

The alternatives to a "longscrew" were the "Tucker" fittings,(tee, coupling/hub, etc.), which had a hub on top and threads on the bottom.

Reply To This Message


Note: Inappropriate messages or blatant advertising will be deleted. We cannot be held responsible for bad or inadequate advice.

Warning: Plbg.com has no control over external content that may be linked to from messages posted here. Please follow external links with caution.

Plbg.com is strictly for the exchange of plumbing related advice and NOT to ask about pricing/costs, nor where to find a product (try Google), nor how to operate or promote a business, nor for ethics (law) and the like questions.

Plbg.com is also not a place to ask radiant heating (try Heatinghelp.com), electrical or even general construction type questions. We are exclusively for plumbing questions.

Please visit:
FAMOUS PLUMBINGSUPPLY the award winning plumbing, kitchen and bath catalog. The largest selection of plumbing products and supplies on the net with pver 1,600 pages in our online plumbing catalog. Since 1995 the PlumbingSupply Group has been serving the entire Internet community.

Click here to view our old forum messages


Please visit:
FAMOUS PLUMBINGSUPPLY the award winning plumbing, kitchen and bath catalog. The largest selection of plumbing products and supplies on the net with over 1,600 pages in our online plumbing catalog. Since 1995 the PlumbingSupply Group has been serving the entire Internet community.


to: Contact Us
to: Plumbing Manufacturers Address Directory
to: Plumbing Links Site
to: theplumber.com
to: Plbg Statistics
to: our FAQ's
to: Advisor List
to: How to show an image
to: Tankless Water Heaters
to: Common Plumbing Terms