The effects of valve wheel size, operation position and in-line pressures on required torque for gate valves


  • Sean C. Parks,

    1. Phillips Petroleum Company, Puerto Rico Core, Guayama, Puerto Rico 00785
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  • Lawrence J. H. Schulze

    1. Associate Professor and Director, NIOSH-ERC Occupational Safety Engineering Program, Department of Industrial Engineering, University of Houston, 4800 Calhoun Street, Houston, Texas 77204-4812
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Some of the hazards encountered by process plant operators involve the operation of in-line valves to control, start, and to stop flow. Torque required to operate valves may vary according to valve wheel size, in-line pressure, and valve flange position (open/closed). This study determined how valve wheel size, in-line pressure and valve position (open/closed) affect torque required to actuate a valve. Data were gathered with each combination of size, pressure and position for 336 valves in an operating petrochemical process facility. The results indicate that the main effects of valve wheel size, the in-line pressure, and open/closed valve position significantly affect operational torque requirements. In addition, the interaction between position and pressure was significant for operational torque. The implication of these results is that operators are exposed to operational torque requirements that exceed maximum acceptable capabilities that have been determined in previous studies.