Seeping threaded fittings... *stainless/brass plastic*

[Deuce]

I take it this is a threaded joint?
What are you putting together?

Yes, threaded fittings. Everything else we don in solvent weld as far as possible.

The equipment itself is mostly pool filters/pumps. Which are normally all done with solvent weld. But we have to make the kit modular, mobile and very tough, so we often go onto stainless/brass fittings. We use composite bulkheads to go from one to the other unless we have no choice but to directly mate metal and plastic threads..

 

[Deuce]

Don't use actual Boss White on anything plastic. It is oil based and will react with most plastics and destroy it

Thanks. As it happens I just ordered Loctite 5331 for the plastic threads. So should be all OK.

 

[ShaunCorbs]

Loctite 55 for metal to plastic threads
Loctite 577 for metal to metal threads

 

[ShaunCorbs]

Thanks. As it happens I just ordered Loctite 5331 for the plastic threads. So should be all OK.

Never tried that myself let us know how you get on

 

[Last Plumber]

Yes, threaded fittings. Everything else we don in solvent weld as far as possible.

The equipment itself is mostly pool filters/pumps. Which are normally all done with solvent weld. But we have to make the kit modular, mobile and very tough, so we often go onto stainless/brass fittings. We use composite bulkheads to go from one to the other unless we have no choice but to directly mate metal and plastic threads..

I see. I was asking just to make sure that they are taper threads and not face joints.
If you've sorted it, then all's well and good.

 

[Deuce]

I see. I was asking just to make sure that they are taper threads and not face joints.
If you've sorted it, then all's well and good.

Most are taper threads, some straight. For straight we normally apply sealant on male and female, rubbing it down right into the threads before assembly. This generally means the sealant isn't just pushed down the female thread. Obviously a lot is... But we don't have to worry about contamination as not potable water. Also anything that is pushed down the thread, will get picked up by filters down the line.

But is there a better way for straight threads?

 

[Last Plumber]

Most are taper threads, some straight. For straight we normally apply sealant on male and female, rubbing it down right into the threads before assembly. This generally means the sealant isn't just pushed down the female thread. Obviously a lot is... But we don't have to worry about contamination as not potable water. Also anything that is pushed down the thread, will get picked up by filters down the line.

But is there a better way for straight threads?

More often than not, yes.
What make/ type of fitting are you using and I'll let you know if there is a better way.

 

[Deuce]

This kinda stuff..

Low Pressure Stainless Steel Fittings - Dual Pumps

Or

Low Pressure Brass Fittings - Dual Pumps

From any number of manufacturers. We often get very short lead times and have to hunt the UK for stock.. But essentially, brass and stainless. Typically 1" - 2".

 

[Last Plumber]

This kinda stuff..

Low Pressure Stainless Steel Fittings - Dual Pumps

Or

Low Pressure Brass Fittings - Dual Pumps

From any number of manufacturers. We often get very short lead times and have to hunt the UK for stock.. But essentially, brass and stainless. Typically 1" - 2".

Most look like taper threads. The ones that aren't sometimes you can get a fibre washer to sit in the female if there is a shoulder inside so that the male will screw right down onto it but that is normally only possible when the male will screw fully in easily, as in parallel threaded or not tapered enough to tighten into the female thread, if that makes any sense at all?

Do you use BES?

 

[Deuce]

Most look like taper threads. The ones that aren't sometimes you can get a fibre washer to sit in the female if there is a shoulder inside so that the male will screw right down onto it but that is normally only possible when the male will screw fully in easily, as in parallel threaded or not tapered enough to tighten into the female thread, if that makes any sense at all?

Do you use BES?

No shoulder in the female sockets usually. Yes even parallel threads often don't go all the way without quite some effort... plus the thread itself isn't often fully cut for the last 10mm of some fittings. With parallel we probably get less leaks though, as we simply got OTT with sealant. which is messy, yet effective.

We do use BES and others. It really depends what we need and lead time to be honest.