Vacuum pump valve material

[Peter BellParticipant @peterbell11509]

[Peter BellParticipant @peterbell11509]

I have a de soldering station which uses an inbuilt diaphragm vacuum pump. Unfortunately the valve material has perished so its just crumbled away.

Can anyone suggest a suitable material to make a valve from? Its about 2mm thick.

Thanks

[Jeff DaymanParticipant @jeffdayman43397]

Silicone rubber sheet 1.6 mm thick will likely work very well. The link below is to one US supplier that offers it. Note that you will need smooth finish sheet for good sealing – there is one kind of silicone sheet with a fabric- like finish, and the smooth kind.

https://www.mcmaster.com/5787t31

There are UK suppliers – look under gasket and seal suppliers. Good luck.

[Michael GilliganParticipant @michaelgilligan61133]

EDPM, as used for pond liners, might do it

I successfully used it to rebuild an electric shower valve, 'though I'm not sure whether vacuum would cause any problem with out-gassing.

MichaelG.

[TrevorhParticipant @trevorh]

EPDM rubber sheet will work good upto -1000mb – we use it on some plant I work on with no noticeable problems

cheers

[Neil WyattModerator @neilwyatt]

A cheap source might be to cut the base out of a silicone cake 'tin', available in your local supermarket…

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Trevorh on 07/09/2018 15:48:41:

EPDM rubber sheet will work good upto -1000mb – we use it on some plant I work on with no noticeable problems

.

That's good to know, Trev

MichaelG.

[Tim StevensParticipant @timstevens64731]

It looks rather as though the backing metal plate is coated with solder. This won't have helped keep the soft valve sheet in good condition. Is it possible to add eg a sheet of stainless mesh between the inlet and this valve? This might intercept some at least of the solder (and it wont usually stick to stainless).

In fact it would be a sound plan to renew the metal plate (with polished stainless) so the new sheet of silicone has a flat surface to close against.

Hoping this makes sense … Tim

[Jeff DaymanParticipant @jeffdayman43397]

Did you get the pump going again Peter (OP)?

[not done it yetParticipant @notdoneityet]

One is not likely to get a pressure difference of much more than one bar in our atmosphere.

Should there be a catch-pot between the desoldering tip and the pump, to avoid solder ingestion by the pump?

[Peter BellParticipant @peterbell11509]

Yes I got it going after I remembered that I had some 1mm roofing grade rubber in stock so made a valve out of that. Experimented unsuccessfully with different style valves before copying the original.

I drew the shape then printed the image onto film, selotaped together and then cut it out with a scalpel. I found it difficult to get the shape neat and shown is a practice valve with larger holes for the clamping screws to adjust the position.

There are a couple of felt filters in line to stop solder ingress also a glass tube to collect it. Works quite well, hope it continues! To get one I had to buy 2 so got a spare I dont need and intend disposing of it soon.

Quite well made (and heavy) apart from the valve material!

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