Torque is the main factor of the operating ball valves, some of the ball valves require an external device to overcome this torque. Hence, torque analyzing and simulation is becoming important to choose the appropriate actuators and on the other hand to control the quality of the valves. There are a lot of factors which influence the ball valve’s torque such as friction between ball and seat, stem and packing, etc. that the engineers should consider in designing valves. The valve’s designers calculate the valve’s torque, theoretically before manufacturing and it needs to be verified by a torque tester after manufacturing. Quarter turn valves torque is a function of its travelling angle, so the torque amount is a diagram with the vertical axis shows the torque amount and a horizontal axis shows angle of travelling of the ball. Though, there are some critical point which the torque amount of them are the most important valve’s parameter and they called Break to Open (BTO), Break to Close (BTC), End to Open (ETO) and End to Close (ETC).
These days, many companies provide torque tester to measure and calculate the actual torque of the valves, but only for small valves with the maximum 6 to 10 inch of the nominal diameter. BVTT 4256 is a Ball Valve Torque Tester designed and manufactured by PETRO ARSAM Co. to measure the actual torque of the huge quarter turn valves with a wide range of torque calculation. BVTT 4256 is designed to measure torques over 250,000 N.m. for the ball valves with the nominal diameter of 42 to 56 inches. It uses a strong yoke mechanism to convert the linear force of huge a set of hydraulic cylinders to a rotation motion and torque generation.
To summarize, BVTT includes two separated units named 1) control and power unit 2) actuating unit, in which the operators will set up the test procedure by the control unit and the actuating unit has the duty to turn the valves and send the feedbacks and details of the travelling to the control unit, then the control unit which is equipped by an industrial computer (touchable panel PC) process the received data and turns it into graphical diagrams and extracted amounts of torques in specified angles of valve travelling (critical amounts of torque) PETRO ARSAM BVTT is a unique machine to designed to measure huge valve’s torque. It is totally automatic and user friendly with customized interface panel and equipped by a powerful Hydraulic Power Unit (HPU).
