Valves: Differential Pressure Torque Test / Gear Ratio Question

[BigSerg]

Hello All,

I have a 12" 900# Slab Gate Valve that I intend to perform a differential pressure torque test on. During the torque test, the valve will be equipped with a gear operator and pressurized on one side to the Maximum Operating Pressure (2160 psig). I have rigged up a fitting to be able to mate a digital torque wrench to the stem of the gear operator. However, I need to know the torque required to open the valve under pressure at the stem of the valve (without the gear operator). How could I determine the gear ratio of the gear operator since I will need that value to calculate the breakaway torque at the stem? Would the number of gear operator handwheel revolutions required to bring the valve from a fully closed to fully open position be my gear ratio? Sorry if this is a rather elementary question. Any help is appreciated. Thanks in advanced.

 

[cloa]

Its Valve Engineering question not a Boiler/Pressure Vessel question.

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[EnergyMix]

A few minutes after posting here he found the valve forum where he's getting answers: See thread408-347045. It would be best to post over to that thread.

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