Safety valve relieving capacity is based on the set pressure of the valve and the size of the orifice in the valve the steam must pass through to get to the atmosphere. If you can, I suggest measuring the orifice then comparing it with the tables in a Kunkle or other modern relief valve manufacturer's catalog. Most of this information is available online.

Good luck,

Paul

Maybe you should contact the Crosby employee who set up the Crosby blueprint and historical info site on the net, his name is Craig, and see if perhaps he has any info on the valves that are that old. The other option is to dig through the old Locomotive & Car builders Cyclopedias and try to find a Crosby add from the correct time frame.

Best of luck to you,

1 Boiler Horsepower is equal to 34.5 pounds of steam per hour.

With the very important qualifier that the steam is at atmospheric pressure (0 psig) and no superheat, and the feedwater was at a full 212 degrees F.

Those of course are far from the conditions that would prevail when the valve opens for testing...

I think I would try the going to the Chief Inspector approach. This sounds like a bureaucracy problem not a mechanical problem.

So the solution is to replace the valves with modern ones that are no where near as well made? And this is safer somehow because a number is missing? Definitely a bureaucracy problem.

It might also be possible that you could have a qualified ASME shop to test, rate, and report the data you need. I have used such a shop to rebuild Lunkenheimer pops - PM me and I will pass along their info and you can inquire with them to see if they can test and report the data you need - I have no stake in their business, but I can vouch that they do fine work for a reasonable price. Yes, their first response will be - we'd love to sell you new Kunkle valves or similar, but they've been rebuilding pressure pops and valves for 60+ years for the power industry.

Regards,
Sully

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