This article aims to resolve the problems that can occur when high actuator torque has a negative effect on the stem of the valve in offshore service. In fact, it is important that the stem of the valve has higher torque capacity than the actuator torque. Different solutions to achieve this will be reviewed in this case study.
Valve trim materials are pressure-containing parts which should have the material quality minimum to the body of the valve. The main trim components, which are also called “wetted parts”, are closure member, seat and stem. The stem of the valve should have sufficient mechanical strength to withstand the loads implemented from the operator. Table 1 provides typical stem materials for different body material of the valves in the offshore industry.