PFTE Sealant~How Tight?

Old 04-29-20, 03:04 PM
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PFTE Sealant~How Tight?

I am reworking a garden irrigation system, again.
This time I will use a non hardening sealant, called PFTE? I will go get some in the morning. Locally I can buy Oatey Great White Sealant.
I have never used it before but it's what is recommended for PVC and plastic such as the sprinkler system valves I am using.
I don't want to overtighten but I need it to seal.
The problem is that from the 3/4" MPT to 1/2" slip fittings that I will use to connect to a feeder manifold will be glued needless to say so I have to be certain that the MPT fitting is tight enough to seal with the sealant. Once the lower part is glued in place I will not get able to change the 3/4" fitting tightness of course.
Any advice is helpful.
Old 04-29-20, 03:13 PM
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First off anytime you put pvc together you dont tighten it like its a nut on a bolt... turning it until it won't turn anymore. That's a great way to crack the fittings. When using tee paste, you only need to turn pvc fittings maybe 1 turn more than hand tight. It's hard to explain, but you just get a feel for what is too tight.

There is also a trick to putting things together in the right order, especially if you arent planning on using a union. That's why unions are used. So that you can simply connect the union in the end.
keninaz voted this post useful.
Old 04-29-20, 03:14 PM
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I have never used sealant on those fittings. I wrap them with the pvc tape. I have never had a leak that way. I have been a mechanic so I just go by feel. That is a pipe thread so needs to tightened pretty tight.
Old 04-29-20, 03:19 PM
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Thanks, I had thought I read somewhere that 1 to 1 1/2 turns past hand tight was enough but could not find it again and the label on the product as shown online by the manufacturer does not say.
Again, no unions, the ones at 4 local suppliers are trash at best and will not seal, I tried. I even tried to change the o-rings but could not come up with the correct size anywhere so I just hard piped the system.
Made in China I guess?

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