Eight Ways to Increase the Life of Regulating Valves

1) Wide open work The extended life method allows the valve to operate at its maximum opening, such as 90%, from the beginning. In this way, cavitation, erosion, and other damage occur at the head of the valve plug. With the destruction of the valve core, the flow increases, and the corresponding valve is closed a bit, so that it continues to be destroyed and gradually closed, making full use of the entire spool, until the valve core and sealing surface damage, can not be used so far. At the same time, the wide opening of the work to throttling clearance, erosion weakened, which compared to the beginning of the valve to work in the middle and small opening degree to increase life expectancy 1 to 5 times. If a chemical plant adopts this method, the service life of the valve is increased by 2 times.

2) Decrease S Increase working opening Increase life span method Decrease S, ie increase the loss of the system except the control valve, so that the pressure drop distributed to the valve is reduced. In order to ensure that the flow passes through the regulating valve, the adjustment valve must be enlarged. The opening, at the same time, the pressure drop on the valve is reduced, so that cavitation and erosion are also weakened. The specific measures include: after the valve orifice plate orifice throttling consumption pressure drop; close the pipeline on the series of manual valve, to the control valve to obtain a more ideal job opening so far. It is very simple, convenient, and effective to use this method when the valve selection is large and it is at a small opening degree.

3) Reducing the opening diameter and increasing the opening degree of the working life The life span method increases the working opening by reducing the diameter of the regulating valve. The specific measures include: 1 Replacing a valve with a small diameter, such as DN32 and DN25; 2 valve Without changing the body, replace the valve seat with a small seat diameter. For example, when a chemical plant is overhauled, replacing the dgl0 with dg8 will increase the life expectancy by a factor of two.

4) Transfer damage location The life increase method shifts the place of serious damage to a secondary position to protect the sealing surface and the throttle surface of the valve seat.

5) Increased throttling passages Increased life-span method The simplest way to increase the throttling passage is to increase the number of valve seats so that the valve seat bores increase and form longer throttling passages. On the one hand, it is possible to delay the sudden expansion of the closed flow throttling, to transfer the damaged position away from the sealing surface, and on the other hand, to increase the throttling resistance and reduce the recovery of the pressure. Erosion weakened. Some of the valve seat holes designed to step-style, wave-style, is to increase resistance and weaken cavitation. This method is also very effective when used in the introduction of high pressure valves in installations and when the older valves are improved.

6) Changing the direction of flow to improve life expectancy The flow opens to the direction of flow, cavitation and erosion mainly act on the sealing surface, so that the valve core and the valve seat sealing surface are quickly destroyed; the flow closed type flows towards the closed direction. , cavitation, erosion effect in the throttling, the valve seat sealing surface below, to protect the sealing surface and the valve core, to extend the life. Precautionary use of the open-type valve, when the problem of prolonged life is more prominent, just change the flow to extend the life of 1 to 2 times.

7) Use of special materials to improve life-span method For anti-cavitation (breaking shapes such as honeycomb dots) and flushing (streamlined small grooves), special materials resistant to cavitation and erosion can be used to manufacture throttles. This special material is 6YC-1, A4 steel, Stellite, cemented carbide and so on. For corrosion resistance, materials that are more resistant to corrosion and have certain mechanical and physical properties can be used instead. This material is divided into non-metallic materials (such as rubber, PTFE, ceramics, etc.) and metal materials (such as Monel, Hastelloy, etc.).

8) Change the structure of the regulator valve to improve the life of the method to change the valve structure or choose a valve with a longer life to achieve the purpose of improving life, such as the use of multi-stage valves, anti-cavitation valve, corrosion-resistant valves.