Edwina Dorsey Valves April 14th, 2019 - 12:34:24
In order to achieve the best performance of valves, manufactures must take many important design factors into consideration. These factors include actuator or positioner design, valve response time, valve type and sizing, and dead band.
A valve such as this operates the same as a ball valve. This valve contains a flat round plate that is placed in the middle of the pipe, as well as the plate has a bar inside that is joined to a switch in the outer valve portion. This type of valve functions by revolving the handle as well as the plate in similar position or vertical to the movement. Unlike the ball valve type, the butterfly valve is constantly present in the movement; thus there is always a moderate drop in the pressure in the movement regardless of the valve's position.
Among all the above mentioned considerations, it is rather necessary to talk about the actuator and positioner design. These two must be considered together. The combination of them affects the static performance (dead band), as well as the dynamic response of the control valve assembly and the overall air consumption of the valve instrumentation.
Valve response time is another important factor for us to consider. For optimum control of many processes, it is important that the valve reach a specific position quickly. A quick response to small signal changes is one of the most important factors in providing optimum process control. Valve response time includes both the valve assembly dead time, which is a static time, and the dynamic time of the valve assembly. It is important to keep the dead time as small as possible. Dead band, whether it comes from friction in the valve body and actuator or from the positioner, can significantly affect the dead time of the valve assembly.
With the rapid development of different industries such as modern nuclear, petrochemical, electric and space, automatic control for process technology and long-distance fluid transportation, a lot of modern low-temperature valve, vacuum valve and control valve are in great need. So in order to ensure the good sealability and suitable strength of the above-mentioned valves, to develop new materials will be a great challenge. As it should be, just to improve the sealing ability and strength for future valves is not enough. It is suggested that the manufactures should expand other parameters of the valve and develop energy-saving, automatic and multi-functional valves, such as low-temperature one used for liquid oxygen, hydrogen or natural gas, vacuum valve, safe valve and so on
There are many types of ball valves that are extensively used in various industries depending upon their designs, sizes and pressure handling capacities. Full port, reduced port, cavity filler, V port, trunnion ball valves and multiport valves are the common ones.