Christopher Tidy wrote:
Just thought I'd post a couple of pictures of the vacuum pump I was
talking about last month. It's a little Edwards ED 35 two stage pump
which I found in a local laboratory's skip (dumpster) last year and have
spent a bit of time restoring. I had the motor rewound, repainted it,
stripped and cleaned the pump and fitted new springs and seals, and
mounted it on some anti-vibration feet. Now it works very sweetly and
holds its vacuum for more that a week after I switch it off. I'm
planning to use it for some experiments on electrical discharges in low
pressure gases. I'm meaning to create a web page with some pictures of
the restoration, but so far I haven't got round to it, so I thought I'd
share a couple of pictures.

Here's my page on overhaul of such pump:
http://www.iki.fi/ktu//es50/es50_overhaul.html

This is the single-stage (ES) version, the double
stage (ED) version has two rotary vane units.
Otherwise very similar - the failing output valve
is identical in both.

These old pumps really last for ever, with
tender loving care from user.

Kristian Ukkonen.