1, open working method of prolonging life
Let the control valve as far as possible from the outset work at the maximum opening, such as 90%. In this way, cavitation, erosion and other damage occurred on the valve head. With valve damage, traffic increases, the corresponding valve to shut, so continue to destroy gradually shut down, the entire valve fully used until the sealing surface of valve core roots and destruction cannot be used. Meanwhile, larger throttle opening work clearance and erosion weakened, it's better than a start valve open in the middle and a small opening work on improving life expectancy more than 1~5 times. Such as a chemical plant using this method, the service life of the valve twice.
2, reduce s increase increase in work-life method
Reduce the s or increasing losses apart from the control valve, the system, assigned to the valve on the pressure drop lower, in order to ensure the flow through a control valve will increase valve opening, and decrease pressure drop across the valve, gas corrosion, erosion has weakened. Specific measures include: valve pressure drop after the orifice consumption, shut down the pipeline series manual valve, to control valves were a dream job opened up. For a start valve is selected when it is in a small opening work, using this method is very simple, easy, and effective.
3, narrowing the diameter increases increase in work-life method
By opening valve diameter is reduced to increase the work, specific measures are: ①-for a small-caliber valve DN32 to DN25; II the body does not change, replace the small diameter of the valve seat valve seat. If overhaul will choke when dgl0 a chemical plant replacement dg8 raised life expectancy by 1 time.
4, transfer, failure to improve life method
Worst place to destroy a secondary position, to protect the valve seat sealing surface and throttle.
5 improve, increase throttle channel-life method
Increase throttle channel is the most simple padded seat, the valve seat hole growth, forming longer throttle channel. On one hand can suddenly expand and flow closed-throttle delay passes the failure location, away from the sealing surface of the other hand, adds throttle resistance, reduces the degree of pressure, cavitation weakened. Some holes designed seat into steps, wave, is to increase drag and reduce cavitation. This method is the introduction of high-pressure valve device in and improve the old valve is often used, is also very effective.
6, change the flow of increasing life expectancy method
Away toward the open direction of flow, cavitation and erosion on the sealing surface of the main role in, the roots of the valve core and the valve seat sealing surface damaged soon; flow closed-closed-direction flow, cavitation and erosion after the throttle, valve seat sealing surface, roots protect sealing surface and the valve core, extended life expectancy. Pretending to be valve of the flow type to use when extending life when more prominent problems, you can simply change the flow of life extension 1~2 times.
7, using special materials to improve life method
Cavitation (disruptive shapes such as honeycomb dots) and flushing (streamlined small ditches), can use cavitation erosion and erosion-resistant special material to produce the choke. This special material 6YC-1, A4, Si Tailai, carbide, etc. For corrosion resistance, instead, is more resistant to corrosion and mechanical properties, physical properties of the material. This material is divided into non-metallic materials (such as rubber, PTFE, ceramic, etc) and metal (such as Hastelloy and monel) categories.
8, change the valve structure-life method
To change the valve or valves selected for their longer life expectancy approaches to achieve the goal of improving life, such as multi-stage type valves, valves, corrosion-resistant valves and other counter-steam Eclipse.