Kunkle safety valves

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makinsmoke
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Re: Kunkle safety valves

Post by makinsmoke » Mon Aug 17, 2020 7:14 am

Thanks Gents!

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PeterCraymer
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Re: Kunkle safety valves

Post by PeterCraymer » Mon Aug 17, 2020 9:17 am

The following information was given to me some years ago. It should help get you in the ballpark.

HEATING SURFACE
ref. ASME Section I, 1971; paraphrased
The number and size of safety valves needed is determined on the basis of the pounds of steam generated per hour per square foot of heating surface.

Heating surface is any surface exposed, directly or indirectly, to the heat generated in the firebox on one side and the other side is exposed to the interior or pressure side of the boiler. The area used shall be measured on the heated side of the plate.
Firebox, combustion chamber, flue sheets, flues, circulators, arch tubes, thermic siphons, water bar
tubes, and superheaters (front end throttle only) are examples of heating surfaces.

MINIMUM POUNDS OF STEAM PER HOUR PER SQUARE FOOT OF HEATING SURFACE

Fuel Type & Firing Method Firetube Boilers Watertube Boilers
Hand fired 8 lbs. per hour/sq.ft. 8 lbs. per hour/sq.ft.
Stoker fired 10 lbs. per hour/sq.ft. 12 lbs. per hour/sq.ft.
Oil, gas, or pulverized fuel fired 14 lbs. per hour/sq.ft. 16 lbs. per hour/sq.ft.
Total # of sq. feet of heating surface x lbs. per hour/sq. ft. = total boiler steam generating capy. in lbs. per hour

ref. CFR 49 Part 230.48; paraphrased

When all safety relief valves are open they must prevent the boiler pressure from exceeding 6% above MAWP. An accumulation test may be used to verify the safety relief valve capacity.

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Bill Shields
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Re: Kunkle safety valves

Post by Bill Shields » Tue Aug 18, 2020 9:28 am

Depends on how you size the orifice and exactly where you put it. Do it wrong and problems
Too many things going on to bother listing them.

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Bill Shields
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Re: Kunkle safety valves

Post by Bill Shields » Tue Aug 18, 2020 6:24 pm

Amcan result. It is often necessary to change the reset pressure to a lower value as Fender has outlined (if you can). It is a slippery slope..
Too many things going on to bother listing them.

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