Valve selection principles in the oil and chemical industry
Classification and in the face of so many valve under various working conditions is so complex, to select the piping installation is most suitable for valve products, the first should understand the characteristics of the valve; Second should master valve steps and basis; Moreover should follow the principle of choosing valves for petroleum, chemical industry. Choose the principle of petroleum, chemical industry valve: port for straight through the valve, the flow resistance is small, usually choose as the cut-off valve and open media use; Easy to adjust flow valve as the control flow; Cock valve and ball valve is suitable for reversing shunt with; Closed with wiping pieces along the sealing surface of sliding valves are best suited for medium with suspended particles. , globe and open the medium with the valve port for straight through the valve, the flow resistance is small, usually choose as cut-off valve and open media. Closed down type valve ( Cut-off valve, plunger valve) Due to its port twists and turns, flow resistance is higher than other valves, so less to choose. At higher flow resistance is allowed in the occasion, can choose close type valve. Second, the control flow of the valve usually choose easy to flow adjusting valve as control flow. Closed down type valve ( Such as globe valves) Suitable for this purpose, because it has a seat is proportional to the relationship between size and shut down a trip. Rotary valve ( Plug valves, butterfly valves, ball valves) And bending the body type valve ( Clamp valve, diaphragm valve) Can also be used to throttle control, but usually only apply within the size of the valve co. , LTD. Gate valve with disc disc on circular seating a crosscutting exercise, it is only when nearly closed position, to better control the flow, so don't usually used for flow control. Three, the reversing valve according to the needs of the reversing shunt shunt, the valve can have three or more channels. Cock valve and ball valve is suitable for this purpose, as a result, most used in reversing the shunt valve selection cock valve and ball valve in this type of valve, a. But in some cases, other types of valves, as long as the two or more valves are properly connected to each other, also can use for reversing shunt. Four, with a medium of suspended particles with the valve when the medium with suspended particles, and the most suitable for use it off along the sealing surface of sliding valve with wiping. If close to the seat back and forth movement is vertical, then can clamping particles, so unless the valve sealing surface material allows embedded particles, otherwise only applies to basic cleaning medium. Ball valves, plug valves, butterfly valves in the process of opening and closing of sealing surface are all in the wiping and therefore suitable for use in medium with suspended particles. At the moment, no matter in petroleum, chemical, or in other industries of piping system, valves applications, operating frequency, and service, to control or eliminate even low leakage, the most important, the most critical equipment or a valve. The final control valves, valve in the field of various industries service is unique and reliable performance.