Selection of valve first to master the performance of the media, flow characteristics, as well as temperature, pressure, flow rate, flow, and other performance, and then, combined with the process, operation, safety factors, select the corresponding type, structure, type and specification of the valve.
Select Valve According To Flow Characteristic
The shape of the valve opening and closing parts and the valve flow passage make the valve have certain flow characteristics. This must be taken into account when selecting valves.
(1) Valves For Cutting Off And Connecting Media
Usually choose a small flow resistance, flow channel for the straight-through Valve. These valves have gate valves, globe valves, plunger valves. Downward closed valves, as the flow channel twists, flow resistance is higher than in other valves, so less choice. However, in allowing a higher flow resistance of the occasion, one can also choose to close the valve.
(2) Valves For Flow Control
Valves that are easy to adjust flow are usually selected. Such as control valve, throttle valve, plunger valve, because its seat size and open firmware is proportional to the stroke. Rotary (such as plug, ball, butterfly) and flex (pinch, diaphragm) valves can also be used for throttling control, but usually only in a limited valve size range. In most cases, people usually use to change the globe valve disc shape for throttling. It should be noted that it is highly unreasonable to achieve throttling by changing the opening height of the gate or globe valve. Because, the medium in the pipeline in the throttling state, the flow rate is very high, the sealing surface is easy to be washed away, loses the role of the cut-off seal, similarly, the use of the throttle valve as a cut-off device is also unreasonable.
(3) Diverter Valve
The valve can have two or more channels for reverse flow and is suitable for use with plug and ball valves. Most reverse flow valves use this type of valve. In some cases, other types of valves, properly connected to each other by two or more valves, may also be used as a medium reverse shunting.
(4) Valve For Media With Suspended Particles
If the medium with suspended particles, the most suitable for its opening and closing parts along the sealing surface of the sliding with the role of wiping the valve, such as flat gate valve.
Post time: Jul-28-2021