PTFE Gasket for #67 LWCO and #14B blow-down valve?

Ken Johnson

Hi,

For years I have been using PTFE (Teflon (tm)) gaskets between a McDonnell Miller #67 LWCO and the matching #14B blowdown valve. They have always sealed well and come off cleanly for the annual cleaning of the LWCO and valve. Unfortunately, my local supply house has stopped carrying them, and only has the fiber gaskets. My experience is that the fiber gaskets are a pain to clean off. [The fiber product is: McDonnell & Miller 313200 Model 37-39 - Gasket]. Does anyone know of an online source for this kind of product? My searches have only turned up the fiber gaskets.

Thanks,

Ken

Danny Scully

Why don’t you ask your supplier where they got them from?

EBEBRATT-Ed

This is a real simple fix. Buy a can of "never seize, "anti seize" etc. Put some on the gaskets and the bolts.

You will never have a problem getting the gaskets off, in fact they will fall off. The bolts will come out easily. I have even used "never seize" as pipe dope (with Teflon tape) on anything that will be removed from time to time, It works great on aluminum parts, gas valves etc.

Most of the time when I take low water controls apart to clean, I just use the old gaskets over again and they never leak.

Ken Johnson

Danny Scully said:

Why don’t you ask your supplier where they got them from?

A sensible and reasonable idea. Unfortunately for me, my supplier would (reasonably) prefer to spend time on bigger customers who purchase more expensive parts more often than I do. Today I was left feeling lucky that they looked for the part I wanted at all. ( I did bring a sample along, so it was pretty clear what I needed.)

Leon82

You can buy a sheet and cut some or there are places that will make them.

But if you don't use them often it may be too expensive

Ken Johnson

Leon82 said:

You can buy a sheet and cut some or there are places that will make them.



But if you don't use them often it may be too expensive

Until today I had been doing that for some years -- I have an old Allpax washer cutter and I had purchased a PTFE sheet from McMaster-Carr. I used one of those gaskets for reassembly, and had a slow leak. Even after tightening all the bolts a bit.

Drained the boiler down again, pulled off the valve, and polished the mating face of the valve. (Move it over sandpaper on a marble block). Put it back with a new self-made gasket. Still had a slow leak. Pulled off the valve, polished the mating face of the LWCO. Put it back with the last commercial PTFE gasket I had in stock. No leak. Now, I changed two things in that last go-round, but I was running out of time for this project.

I would not have expected the home-made gaskets to 'go bad' in storage. In texture, feel, and appearance they seem just like the commercial one. Still, I would feel better with some of the commercial ones in my stock of spares.

Leon82

I wonder if the factory ones you had were a different formula.

Ken Johnson

I have learned through private correspondence that these PTFE gaskets are available from R. F. Gansereit. ( www.boiler-gaskets.com ). They can be ordered by phone; their part number is MM 37-39 T.

I have placed an order.

EBEBRATT-Ed's anti-seize and fiber gaskets was my next alternative; but it is no surprise that my first choice is to go with what I know.

Thanks for the helpful and insightful comments.