a technical knowledge base for all the process piping professionals around the world...
The Valve Coefficient (also known as Flow Coefficient) of a valve is a relative measure of its efficiency at allowing fluid flow. It describes the relationship between the pressure drop across the valve and the corresponding flow rate. Mathematically the valve coefficient Cv (or flow capacity rating of valve) can be expressed as: where: Q is the rate of flow...
Valves are mechanical devices specifically designed to direct, start, stop, mix, or regulate the flow, pressure, or temperature of a process fluid. Valves can be designed to handle either liquid or gas. By nature of their design, function, and application, valves come in a wide variety of styles, sizes, and...
In refineries, the process fluids flowing through pipes and valves are primarily liquids. With liquids, critical operating conditions caused by cavitation or flashing may occur. Symptoms are increased noise emission, valve and pipe component erosion, low-frequency mechanical vibration in the valve and the connected pipeline or chocked flow etc. Under...
Various types of valves are required in any piping system in order to regulate the fluid flow within that system. Valves can be manually operated or they can have an actuator to change and control the valve opening. The actuator may be pneumatically, hydraulically, or electrically operated. The valves represent a considerable percentage...