Hallite washers

Hello, all

I have been building Super Simplex fir a long time now and have finally got to the superheater, which is now almost finished. In order to seal the regulator output to the superheater the drawing calls for two 1/32” Hallite washers 3/4” od x 1/2” id. These washers sandwich an Oring and are fitted in the output boss on the boiler and the superheater boss when fitted and tightened compress the oring ti form the seal.

I have asked the usual suppliers if they can supply these Hallite washers and it seems no one does and doesn’t know what they are!

can anyone help me with where I can get these? and if you have built Super Simplex what did you use?

TIA

regards

Deric

It looks like Hallite is a UK Co with website, contact phone numbers and on-line expert chat...and google throws up stockists..

https://hallite.com/

The last time i used hallite washers was many years ago. I got them from BSS (British Steam Specialites). It is worth a try if they are still trading.

Andrew.

Like wise have used Hallite seals in the dim and distance past, but don’t remember Hallite washers. Having done a web search seams there is Halite washers, note one l. These appear to be from gasket material referenced a few times on my search as used on Lambretta joint faces. So perhaps not a flexible seal material as such.

Hallite washers are fibre wahers with a wire mesh reinforcement.

Robert G8RPI.

Hallite seems to have disappeared, I needed [wanted] some a short while back but ended up using an alternative from Ebay -- enter Hallite Gasket Material and search you should find something suitable to make your washers from - easy enough to make a couple of one use punches from the scrap box.

My recollection of Hallite is it was a paper based material with graphite impregnated and some form of reinforcement but I don't remember it as wire ? Stand to be corrected of course.

John

Are these bonded seals of any use?

Bonded seals

Used to be able to buy this in a rolled up sheet which was about 1/32 thick have used this in the past for seals on steam boilers may have some ofcuts still as left overs will have to look what i have if any interest , years since i bought any..

Regards Brian

You mean a Dowty washer?

Like NDIY, I wondered if Dowty washers would do the job. Depends on the rubber insert having a high enough temperature capability.

You could make your own washers, by punching out from a sheet of gasket material. Punch the hole first, and then the OD!

Howard

Hi there is a website for Hallite https://hallite.com/contact/ they list a roll of material.

David

.

... I expect Dowty would be pleased to see that  ‘generic’ bonded seals are  not being marketed under their trade name.

MichaelG.

Edited By Michael Gilligan on 12/07/2020 08:31:38

Either the washers or the O-ring make the seal ?

Can't really see why you need both.

Bonded seals/ Dowty washers are used to seal banjo type fittings on hydraulic systems, a particularly specialised function.
Dave W

Here is an extract from the drawing showing the superheater seal location.

i have been offered some glass impregnated PTFE to make washers which I think meant to compress and ‘protect’ the oring. Given that Super Simplex was designed in the mid 80’s Hallite washers were probably the most suitable for this application.

do you think the PTFE will do as good a job, given that it’s good for over 300DegC?

There really is no need for the washers but I presume that you have made the parts to the drawings so the gap for the O ring will be too big for the O ring alone. Your PTFE should be fine to make the washers or you could just make a spacer washer out of brass (put on the boiler side of the O ring) to make the gap the right width for the O ring on it's own.

I've used the O ring seal on several locos and it works very well. Much better than the threaded joints beloved by LBSC which are an absolute pain!

John

That's the name, for the life of me I couldn't remember it. It was only 40 years ago when I used them on a regular basis.

Thanks to all of who have chipped in, your comments are much appreciated.

im going to go for the PTFE solution.

Thanks again

Deric

I know the feeling. Used extensively on hydraulics but the name is often forgotten - when one simply goes to the box of washers!