OldScrawn wrote:
>> Peter Fairbrother wrote:
>>> What is a good mix of materials for a piston/cylinder combo, under high
>>> loads, when no lubrication is available? Fluid is air, helium or oxygen
>>> gas, pressure is 200 bar, temperature might reach 200C worst case.
>> That sounds pretty demanding to me. What is it, a diving compressor? I'm away
>> from the office (and all my literature) for a week, but I'll have a think.
> Ground support equipment for model rocketry. It's much smaller than a diving
> compressor though, only 15 l/min.
> It will be used to compress air, nitrogen and scavenged helium for general
> purposes (purging, dumping, tank pressurisation, a few other bits and bobs),
> but the majority of the time it is used as a cryo-refrigeration pump to make
> liquid oxygen.
> Incidently, it has to undergo a safety inspection for insurance purposes,
> and CE compliance / marking if I want to sell them as part of a kit (the
> long-term plan), and I both know and intend to more than follow the safety
> and regulatory requirements. It might be "wicked", but it's not "naughty".
I have ordered some cast iron and phosphor bronze to try.
If anyone is an expert on high pressure compressors and is willing to chat, or knows where to get a compressor like the one described, please let me know.