The service is liquid oxygen with this valve located on the upstream side of the liquid oxygen vaporizers. There is a flow arrow on the side of the valve, but why would it matter if the flow is pushing up on the disc or down on the disc?Additionally, if it is flashing, the preferred flow is generally the opposite of that for the cavitation case. Typically, trim designed for flashing service is similar to compressible flow trims, not incompressible such as liquid and cavitation trims. With anti-cavitation trims, the vapor bubbles are maintained in the inner cavity so their collapse is located away from the trim solid parts susceptible to cavitation damage; however, for flashing service, the vapor fraction is sustained in the flow. Typically, trim designed for flashing service is similar to compressible flow trims, not incompressible such as liquid and cavitation trims. With anti-cavitation trims, the vapor bubbles are maintained in the inner cavity so their collapse is located away from the trim solid parts susceptible to cavitation damage; however, for flashing service, the vapor fraction is sustained in the flow. ValveEngineer123: Yes, that is the design strategy for most multistage trim; however, for lower levels of cavitation, the trim may be designed to allow cavitation in the interior space without inflicting damage to valve. This is often a less costly design as single or lower number of stages are required. Most severe duty control valve manufacturers have designs for both and select the best trim based on the cavitation coefficient and price. The valve may seal effectively with flow in the opposite direction; however, the manufacturer should be contacted to verify. If this is a y-pattern valve, you probably wouldn't want to reverse the installation even if the manufacturer said it could seal.

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