Threaded or Compression Oventrop TRV's?

OG_Simon

Hi folks,

I bought 12, Oventrop valve sets a couple years back and assumed that they were 1/2" compression x 1/2" NPT. I finally unboxed them and well, they aren't, they are straight 1/2" NPTxNPT. A threaded nipple coming up out of the floor to connect the valve is going to be a challenge to get the valve clocked to where I want it. Is there any problem with adding a 1/2" copper pipe compression x NPT fitting so I can have more flexibility with position, Or am I stuck with using an NPT nipple?

Thanks,
Simon

OG_Simon

I should mention that they are to connect Runtal radiators to...

EBEBRATT-Ed

You can use whatever you need to use. If the pipe coming up through the floor is threaded and the valve is threaded your pretty much stuck with threaded. Can you put a union between the floor nipple and the valve? Do you have access to the basement piping to make any changes if you need to. There are no compression connectors for black pipe. Maybe you can change the riser over to copper if that would help.

OG_Simon

Thanks E, I'm thinking something like this, a bit chunkier than just a straight nipple... pic attached

hot_rod

You could adapt like you show. Would you need one below the floor also?

Used to be able to find those in chrome plated versions.

There are some split plastic sleeves also to cover up all the exposed fittings.

OG_Simon

I was thinking going to pex and then back to the manifold.

hot_rod

Perfect, that is a common way to run Pex to panel rads. The correct compression valves would be ideal, but….

Yet other installers run the Pex up through the floor, use a bend support to keep the 90 curl
But you have Pex exposed to UV, so for sure want the snap on covers.

There is always the SharkBite option😏

OG_Simon

Ha! shark bite... The risk takers option.

OG_Simon

Rod,

Is Pex B ok to run in this arrangement? I've read some opinions are that it's ok others that don't like it. I've seen it used in hydronic applications without issue. I used 3/4" to plumb my shop compressor so I know that pressure isn't an issue. Temperature applications I have less experience with.

hot_rod

Type B is fine. Stick with a good brand. I would not expand a B pex, however, regardless of what the manufacturer states.
I prefer the copper crimp ring to the pinch type Otiker crimp rings.