Metal pex (female) connection to poly threads will not stop leaking

[tankmcmanara]

Recently installed an inline water filter in crawl space. On a well. Mfg provides a black plastic/poly type coupler on each side of filter. 1 inch threads into filter, and 3/4 on other end for pipe connection. I connected a 3/4 pex brass female NPT to the poly coupler. Wrapped with about ten layers of tape and still have a tiny leak - about a drop every minute. What is a solution? What are other options? Thanks in advance

 

[Twowaxhack]

it may be defective or it may be poor quality. Contact the manufacturer

 

[Geofd]

Sometimes I think if you put too much Teflon tape on you could stretch the threads,I usually use a brass nipple out of the filter and the adapter to what ever the pipe size is I've also used a males by copper union.you should add a tee and a small bleeder valve to relieve the pressure make it easier to remove the filter

 

[plenumspacer]

What tape do you use?

 

[tankmcmanara]

White teflon plumbers tape

 

[Geofd]

White teflon plumbers tape

I also use teflon paste

 

[plenumspacer]

I also use teflon paste

Ok, I’m gonna share a trade secret with you. Follow this procedure for a leak free threaded connection.

1. Undo all leaky connections and thoroughly clean threads with the brush;
2. Throw away your white Teflon tape or keep it for irrigation purposes;
3. Go to big box store and get Blue Monster tape or grey oatey, your choice;
4. Wrap, three and only three wraps of mentioned tape around your threads clockwise only if using plastic with metal, plastic on plastic - only thread seal only, no tape!!!
5. Secret: Start running your fingernail at the start of your threads clockwise, pushing all the air out between tape and threads (do not tear the tape, otherwise you will have to start from scratch;
6. Apply thread sealant;
7. Tighten lightly plus 2/5 turns, check for leaks. Continue with singular 1/4 turns until leak stops.

*Please follow exact procedure. If it’ll not help, you have two options:
1. Replace plastic adapter with brass one; or
2. Use blue sealant.

 

[tankmcmanara]

Ok, I’m gonna share a trade secret with you. Follow this procedure for a leak free threaded connection.

1. Undo all leaky connections and thoroughly clean threads with the brush;
2. Throw away your white Teflon tape or keep it for irrigation purposes;
3. Go to big box store and get Blue Monster tape or grey oatey, your choice;
4. Wrap, three and only three wraps of mentioned tape around your threads clockwise only if using plastic with metal, plastic on plastic - only thread seal only, no tape!!!
5. Secret: Start running your fingernail at the start of your threads clockwise, pushing all the air out between tape and threads (do not tear the tape, otherwise you will have to start from scratch;
6. Apply thread sealant;
7. Tighten lightly plus 2/5 turns, check for leaks. Continue with singular 1/4 turns until leak stops.

*Please follow exact procedure. If it’ll not help, you have two options:
1. Replace plastic adapter with brass one; or
2. Use blue sealant.

Thanks so much. Will give it a try. The problem seems to be the pex brass female to plastic connection - so thread tape only?

 

[plenumspacer]

Make sure, the sealant is potable water approved.

 

[plenumspacer]

Thanks so much. Will give it a try. The problem seems to be the pex brass female to plastic connection - so thread tape only?

No, both, since you have a PEX brass female adapter. Follow the instructions, you will be fine. If I was you, I would use 1” male to 3/4 pex adapter, bypassing the original one. Let me know

 

[tankmcmanara]

Just to clarify, the pex connector is brass male going into plastic female connection on the filter housing. Use grey tape AND RectorSeal T Plus 2 sealant?

 

[sawsaw]

In my experience dealing with minor leaks, I've simply put a small pan under the leaks and walked away. Checking about three weeks later, the leaks have ceased, not to return.

 

[wpns]

I’m with sawsaw, give it some time and see if it stops.

 

[tankmcmanara]

Sure. Why not. I'll wait. Some people say white Teflon only works well on metal to metal connections. And that if metal to plastic, the plastic should be the female part. Mine is opposite.

 

[Twowaxhack]

Color don’t matter……

I do not typically screw plastic over metal.

Use a compatible pipe sealant. I tighten pvc into metal fingertight and no more than two complete turns with a wrench. No Teflon.

 

[tankmcmanara]

I guess plastic PEX fittings are another option. Then it is plastic on plastic. Right now I have metal going into plastic. If I have not already damaged threads in filter housing.

 

[Twowaxhack]

I use these filter heads for ice makers or kitchen sinks.

They have 3/4” stainless thread inserts.

They take standard filters.

https://www.lowes.com/pd/A-O-Smith-...ViBXUAR2JigjpEAQYASABEgJDAfD_BwE&gclsrc=aw.ds

 

[Bird Doo Head]

If you paste, keep in mind that paste lubricates, so don't go torque-crazy.

If the filter fittings got damaged, you can try Supco's blue (not yellow) Leak Lock. It's very thick and may fill in any damage on the threads. Note that it will be very difficult to unscrew the fitting later.

Leak Lock is common in the refrigeration trade, so it's at your area refrigeration supply house, usually right on the counter. SupplyHouse Com sells it, too.

Paul