The valve operating force shall not exceed 250 N
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Gentlemen, I came across a technical specification for valves that states the operating force required for the valve’s handwheel should not exceed 250 N. I have questions: 1. Is there such a thing as an operating force? Isn’t it the operating torque? 2. The operating force should be measured using a torque wrench, so the unit should be N.m, right? Please help clarify this doubt for us
The operating force mentioned here refers to the strength of a single person using one hand; it is defined based on anthropometry and represents the maximum operating force required for manual valves. The diameter of the handwheel is determined based on torque and operating force, and it must not be too small, as this would make operation difficult
Force multiplied by a lever arm is torque, isn’t it? The same meaning
According to API6D requirements, the opening force of the handwheel shall not exceed 360 N. The diameter of the handwheel generally should not exceed the length of the structure.
The operating force on the handwheel is the circumferential force applied by a person to the handwheel; torque, on the other hand, is obtained by multiplying this force by the diameter of the handwheel. As mentioned on the 4th floor, the 6D valve indeed specifies that the force required to open the handwheel should not exceed 360 N, and this is also the value we use for calculations. However, some specifications mention 445 N as the required force, and this is an average value – in reality, the amount of force applied by a person varies