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Would these parts survive?

Posted: Fri Nov 26, 2010 11:09 pm
by skyjive
Part 1: McMaster 4753K52
Spring-loaded Piston Check Valve with stainless steel seat, spring, nickel-plated brass body

Part 2: McMaster 48435K72
Pop-off valve

Would these parts be okay if subjected to hybrid combustions of say, 30 psi pre-ignition pressure? I would imagine so but thought I'd get others' opinions on the matter.

Posted: Sat Nov 27, 2010 1:25 am
by MrCrowley
So, basically, would they survive a 2x mix? I would think so. Maybe after awhile the seals will fail but it shouldn't be much to worry about.

Posted: Sun Nov 28, 2010 1:30 am
by omniscient
30psi pre-igintion pressure is just short of the required total pre-ignition pressure of a 3x mix.

Using a generic 14.7psia and 0.6psi for each injection, a 1x mix has a pre-ignition pressure of 0.6psig --- a 2x mix has a pre-ignition pressure of 15.9psig --- a 3x mix has a pre-igniton pressure of 31.2psig

A 2x mix will generate a peak combustion pressure of approximately 205psig
and a 3x mix will generate a peak combustion pressure of approximately 308psig

If this 4753K52 valve was to be used for a 2x mix, it should survive for a while because the valve is rated for 200psi@, but only at 300°F

The 48435K72 valve can be ordered at a rating as high as 300psi, but the soft seal pop-off is only rated for up to 250°F

In my experience, pop-off valves and check valves are usually fried, after several firings.

Posted: Sun Nov 28, 2010 1:31 am
by MrCrowley
Ah yes, my bad. Wasn't thinking straight :D