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Diaphram life?

Posted: Tue Mar 29, 2016 4:43 pm
by Crazyguy
I've seen lots of engines running with diaphrams. Has anyone ever had one last a long time before tearing?
Is this a reliable design for a real engine and not a toy?

Re: Diaphram life?

Posted: Wed Mar 30, 2016 1:40 am
by Ian S C
A diaphragm should last quite well, couldn't say how many hours, but think of the diaphragm in the fuel pump on a motor car, or in a gas regulator. These last for years.
Ian S C

Re: Diaphram life?

Posted: Wed Mar 30, 2016 8:31 am
by Crazyguy
I was thinking if you had a diaphram fail on a stirling that pumped it's own cooling water, the engine would stop when the diaphram failed, which would stop the cooling water flow, but the heat source (fire) would be unstopped and the engine and components would overheat (burn up) . It would have to be attended or monitored, or have a thermostat to stop the fire. Or maybe a bimetal vent that would let the heat escape if it got too hot.

Re: Diaphram life?

Posted: Thu Mar 31, 2016 1:06 am
by Ian S C
I think the nearest to a diaphragm in commercial Stirling engines is the "roll sock" seal on a piston, these are rated for tens of thousands of hours continuous running.
In case of break down some means of auto shut off for the gas could be arranged.
Ian S C

Re: Diaphram life?

Posted: Thu Mar 31, 2016 5:27 am
by Crazyguy
I think the "roll sock" type of diaphram is good.

Re: Diaphram life?

Posted: Fri Apr 29, 2016 3:53 am
by Wellington
Ian S C wrote:I think the nearest to a diaphragm in commercial Stirling engines is the "roll sock" seal on a piston, these are rated for tens of thousands of hours continuous running.
In case of break down some means of auto shut off for the gas could be arranged.
Ian S C
Tens of thousands of hrs running time is good enough for me. But what about materials? Which easily available materials will give the longest life do you think?
.Wellington.