Sealing boiler fittings into boiler bushes

I'm sure that this has been asked before ... I am preparing my Conway boiler for its first hydraulic test and I've noticed that the safety blanking plug and the steam pipe header are weeping slightly where they screw into the boiler bush.

What do people recommend/use to seal the boiler fittling etc (The Steam-Pipe Header will need to be Steam tight as well)

Many Thanks

Dave

Hi Dave,

I use Loctite 242 Nutlock with good results.

John

I'd suggest 242 isn't rally the correct product. Try loctite 592 pipe sealant. Good for 400degF Its easy to apply and nice clean joints. Try the plumbers merchants.

Otherwise use ptfe tape for temporay jobs like boiler testing, also from the plumbers

Pete

you shouldnt use loctite for a safety valve plug!

i use clear plastic washers for such plugs. never had a drip yet! as for 'steam pipe headers' i presume this is the wet header from the regulator pipe... it should be perfectly water and steam tight and capable of still sealing with smokebox temperatures.

chhers,

julian

Locktite 574. Specifically designed as a high temp flange sealant. Its not really a locking compound, - its a thread and flange sealant. and is reasonably easy to undo, but still has antivibration qualiites. (592 I don't know sorry, but being a 5 they are possibly in the same series so could well be very similar)

Sets in a couple of minutes, easy to wipe off don't use too much. Seals everything, replaces all gaskets! Perfect - tool for the job. (I have an absolutely leak free traction engine, and an equally leak free Metre Maid, and no extraneous bits of white to get in the boiler and block injectors etc later!).

About £15 for enough to build and keep 2 engines running for 2 years and more! Available from Polly amongst others.

Why should one not use Loctite on a safety valve plug? You need a spanner to undo it just the same? With respect , there are very many Loctites, and while we normally talk of it as being a thread locker, they make, as we know high temp steam sealants, all the way to low strength nutlockers.

Edited By mgj on 20/06/2012 09:00:37

I have stopped the weep on the Safety Valve plug with a piece of gasket material, I plan to use one of the liquid gasket/sealent products when I finally put the valve itself in.

Yes - I do mean the "Wet Header from the regulator pipe" ... It weeps from the treads that screw into the boiler bush ... I have tried the same material as above, but it didn't work, I am thinking of using a copper washer and the "Liquid Gasket/Sealent" (A High Temp one" ... Are their any issues with doing this?

Dave

I have used loctite bearing retainer with great results. Its extremely viscuos and not too hard to undo. Its especially good for sealing around water gauge glass if the fit is less than perfect. Its yellow, smells sweet and tastes awful!