Hello John,

Showing my ignorance, could you please tell me what “PEEK” piston valves
are?

Is this a material similar to Teflon?

Thanks!

Keith Taylor Jefferson, Maine USA



_____

From: halfinchlivesteamforum@...
[mailto:halfinchlivesteamforum@...] On Behalf Of John Baguley
Sent: Wednesday, May 02, 2007 5:03 AM
To: halfinchlivesteamforum@...
Subject: [Half inch live steam forum] Helen Longish



Hi all,

Just been steam testing Helen now that the boiler is finished. I used
the propane torch through the firehole rather than coal as it's more
controllable!

As suspected, the PEEK piston valves were still too tight at the
normal running temperature so I had to keep removing them and skimming
a fraction of the diameter until they were ok. A bit fiddly but
fortunately not a big job as the valves are easy to remove and
replace. I tried measuring the cylinder temperatures but my
thermometer only goes to 150° C and that disappeared off the scale!
The superheaters are stainless radiant type which extend to the back
of the firebox so the steam is well and truly hot!

I noticed that the lubricator doesn't seem to be pumping properly so
the cylinders are probably being starved of oil. I'll look at that
today. It didn't seem to affect the running though as I ran her for
about 30 minutes non-stop last night with no problems.

Looks as though I might be struggling to have her running for Stafford
on the 27th.Depends on how quickly I can knock the tanks and cab up.
Otherwise it's a big water tank on the driving trolley!

John





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