Threading Polypropylene Pipe

[beesbo]

We are trying to thread some 2" Pure Polypropylene Schedule 80 Pipe with Ridgid Model 12-R pipe dies. Our first attempts look pretty bad and appear to fit very loose. Our threads do not look like factory nipple threads.
What is the trick to threading plastic pipe? Is a lubricant necessary? Should we have different dies for plastic? Our threader is new; the dies we have are perfect. Plastic threads quite easily but don't look right.
Bill

[plumberscrack]

even though the die teeth may look perfect they may not be set properly. double check them on a factory cut steel nipple. the nipple should thread just about all the way up by hand. because the plastic is way softer than steel you need to keep it from crushing when threading. try to thread a 1-1/2" nipple into the end of the 2" plastic that should keep it from what us plumbers call a "drunken" :confused: thread. no lube needed.

[PLUMBER RICK]

pvc you can thread with the plastic dies. i don't think polypro is designed to be threaded. they migh be formed threads. the poly i'm use to is the yellow gas sdr 17 and black trenchless sdr11. nevr seen it threaded or purchased with threads.

rick.

[plumbdog10]

I've worked with poly pro pipe in both underground gas installations and in chemical resistant piping. I've never seen it threaded. I have used threaded valves, but the were installed by fusing a male iron pipe adaptor on to the pipe.

You need to contact the manufacturer.

[beesbo]

Thanks for the info. I have attempted to contact manufacturer but they sleep pretty late in California :) It appears from their website that they do a mechanical thread, not molded, when they are making nipples. But looking at the nipple, it aalmost appears to be cut on a lathe with a single die, not our type of threader.
I will post any more info I get from them .
Tks again
Bill

[plumbdog10]

Thanks for the info. I have attempted to contact manufacturer but they sleep pretty late in California :) It appears from their website that they do a mechanical thread, not molded, when they are making nipples. But looking at the nipple, it aalmost appears to be cut on a lathe with a single die, not our type of threader.
I will post any more info I get from them .
Tks again
Bill

beesbo,

I live in California. Private message me the maufacturer, and anything else you have, I will try to get the info for you.

[beesbo]

I did get hold of the manufacturer and according to him, they use a system of three sets of dies that are used one after the other. He says the dies have a propriatory design that they came up with and not really for sale. They do make a really nice looking thread. I believe that for what little threading we would need to do, it is easier for us to just buy nipples, cut them in half and weld them on. We do weld poly pro so it is not a problem.
Thanks for all the help.
Bill

[plumbdog10]

Welcome to the world of exotic plastics. It's always about propriatory tools. Hmmmmmmmmmm? You did the smart thing. Let us know how it came out.