Drop Ear Elbow, Nipple, NPT and IPS

[Xiaotian Guo]

Hi,
A while ago I purchased a Moen 3510 shower valve which has 'IPS' female connector, at the time I did not know the difference between IPS(straight) and NPT(tapered), and thought I could avoid soldering with that connector. Then I found Pex adaptor I purchased and all I could find on internet are NPT ones. So it will be returned. Before that I tried to screw the connector in and see it will only go about half way in.

To compare I took out the drop ear elbow and a NPT nipple (for hand held shower head). They are both NPT so I expect the nipple should go in more than half way. To my surprise, it also only went half way.

In both case, I didn't use any tool, just by hand, but I'd expect with a tool I might get a full turn in both case. Still I expect the NPT to NPT would fit better than MNPT to FIPS?

Am I missing something?

Here is a picture of nipple to drop ear elbow:


Thank you!

 

[hj]

You are missing that the drop ear elbow is designed to have a nipple screwed into it. You are overthinking the threading.and that it is Iron Pipe Size.

 

[Sponsor]

 

[Xiaotian Guo]

@hj thank you for your response.

Are you saying IPS or NPT it doesn't matter? I have read in several places that they are different and should not be used together.

I'd appreciate it if you could explain a bit more. Since they are going to be sealed behind walls, I want to be sure everything is right.

Thanks again.

 

[Cwhyu2]

NPT=national pipe thread IPS = iron pipe size , both are the same type of thread. Just different names.