Pipe thread sizing /standards(this may be a dumb question)

Joe_51

If anyone recalls I'm a newbie/homeowner who is installing a boiler/radiant system in our house we are building.My question is this....I notice that some fittings are labeled IPS and FPT ,both If I understand correctly are female threaded ends, is there a diffence in threads per inch? pitch ? Will MPT male connectors thread into both this fittings ???? Thanks for your help. Joey

John Starcher_4

Man! What a dumb question!!! (just kidding!!)

Joey - IPS = Iron Pipe Size for standard plumbing threads.
FPT = Female Pipe Thread and is standard for plumbing pipe
MPT = Male Pipe Thread, and is, again, standard for all steel plumbing pipe.

So, to answer your question, yes your MPT fittings will thread into a FPT fitting.

One suggestion - I would urge to to consider hiring a pro at least to start up the boiler once it's installed. A combustion test should be performed to assure that it is burning and venting properly - especially if oil.

Good luck,

Starch

Joe_51

and yet another question...

Can a MPT threaded coupling thread into a valve with IPS threads ???? I have met someone (from this site) who is willing to come check out my system and start it up for me when I'm done piping it.

DaveC

IPS seems like a poor way...

to label a fitting, to me. It could be made of some other material (steel, brass, etc.). Or if the "I" stands for inside, it's not exactly that dimension - but more of a nominal designation?

John Starcher_4

It doesn't mean.....

...that the material needs to be "IRON"

Just means it's the same size, and fittings would be compatible. Just like "CTS" for copper-tube-size.

Starch

John Starcher_4

Well......

....a coupling (if I'm understanding you correctly) would have female threads on both ends, so it would not thread into a valve with female threads. Unless you're referring to a pipe nipple with MPT threads on each end, and then that would thread into a FPT or IPS valve.

Confused yet?

Also, glad to hear you've made arrangements for a professional boiler startup!!!!!!

Starch

DaveC

It could be male x female...

I guess that's called an "adapter" though - Kind of like a straighted street elbow. But aren't the male threads on those type of fittings poor quality (or just my imagination)?

Joe_51

I all set

Starch, I 'm clear now. I was worried that IPS and FPT there different thread types/pitch's. Jeb on this board has given me great piping diagrams complete with redoing my heat loss calc. and Rob O'Conner has also given my real world advice and will be the one who will fire it up for me.Thanks

Joe_51

Jim, I'm not using any fancy fitting that have male threads and female threads at opposite ends,.I must have described them wrong.

John Starcher_4

Great!!

You're in good hands.

Starch

Weezbo

APS.

those would be Ambidextreious pipe size...:))) sorry:( i have a stupid sence of humor.

Steve Paul

MXF straight street elbow???

What you are describing is an extension coupling. It has a female pipe thread at one end and a male pipe thread on the other end. It gives you a dimension somewhat shorter than a close nipple and a coupling. It can come in very handy when a tight fit is required. The male pipe threads are quite substantial because the fitting is made from one piece material.

John MacGregor_3

Pipe threads

Just be sure you don't order IPS pipe or fittings from a municipal water works supplier without telling them that what you really want is SPS (steel pipe sizing) sizing, otherwise your nipple/pipe will fall right through the hole, which is quite a bit larger.

bob young

i.p.s.

i.p.s. stands for international piping society

DaveC

That's the description I couldn't remember!

The "straightened street elbow" description was just a way of trying to visualize the fitting. However, a master plumber once told me that no experienced plumber would ever use a street elbow - I assumed it was because the male threads were poor in quality - or is it the "lumpy" looking inside passage that is undesireable?