How to improve the life of the boiler pump control valve

In the industrial automation instrument, the control valve is cumbersome, and the structure is simple, often not be taken seriously. However, it is in the process of pipeline, the working conditions are complex, once the problem, we are busy. Because of its heavy, difficult to find the problem, often effortless, but also involves the system put into operation, the system is complete, adjust the quality, environmental pollution. Today, for everyone to introduce 50 kinds of control valve fault handling methods, after the failure encountered no rush.Click to know Boiler feedwater pumps manufacturers
1, the failure of the boiler pump control valve key inspection of the site:
        1) Body wall
        For the use of high pressure and corrosive media in the occasion of the control valve, the valve body wall is often subject to the impact of media and corrosion, must focus on checking the pressure, corrosion resistance.
        2) seat
        When the valve is in operation, the inner surface of the thread for fixing the valve seat is susceptible to corrosion and the valve seat is loose. For valves operating under high pressure differential, check whether the sealing surface of the valve seat is damaged.
        3) spool
        Spool is the active parts of the valve when working, by the media erosion, the most serious corrosion, maintenance should carefully check the spool parts are corroded, wear, especially in the case of high pressure spool wear more serious (Due to cavitation phenomenon) should be noted. When the spool is damaged, it should be replaced. Also note that the stem also has a similar phenomenon, or loose connection with the spool and so on.
        4) "O" type seals
        "O" type seals and other gaskets are aged, cracked.
        5) PTFE packing
        Should pay attention to PTFE packing, seal grease is aging, with the surface is damaged, should be replaced when necessary.
      2, to improve the control valve to the duration of the method:
        1) large opening work to extend the life method
        Let the start of the valve as far as possible in the maximum opening work, such as 90%. In this way, cavitation, erosion and other damage occurred in the spool head.
        With the spool damage, the flow increases, the corresponding valve and then a little, so continue to damage, and gradually closed, so that the entire spool full use until the spool core and sealing surface damage, can not be used so far.
        At the same time, large opening work gap gap, erosion weakened, which than the beginning of the valve in the middle of the opening and small opening work to improve the life of 1 to 5 times. Such a chemical plant using this method, the valve life increased by 2 times.
        2) reduce the S increase the working opening to improve the life method
        Reduce the S, that is, increase the system in addition to the loss of the control valve, so that the pressure drop to the valve down, in order to ensure that the flow through the control valve, will inevitably increase the valve opening, while the valve pressure drop Cavitation, erosion is also weakened.
        Increase the working opening to improve the life of specific methods are:
        Valve after the orifice throttling consumption pressure drop;
        Close the manual valve in series on the line, to the control valve to obtain a better working opening date.
        It is very simple, convenient and effective to use this method when the valve is selected at the beginning.
        3) Reduce the diameter increase the working opening to improve the life method
        The working opening is increased by reducing the diameter of the valve.
        Reduce the caliber increase the working opening to improve the life of specific methods are:
        For a small size of the valve, such as DN32 replaced DN25;
        The valve body does not change, replace the small valve seat valve seat.
        For example: a chemical plant overhaul when the throttle dgl0 replaced dg8, life increased by 1 times.
        4) Transfer damage to the position to improve the life method
        Transfer the damaged area to a secondary location to protect the sealing surface and throttling surface of the valve seat.
        5) increase the throttling channel to improve the life of the law
        The easiest way to increase the throttling channel is to thicken the seat so that the seat hole grows to form a longer throttling channel.
        On the one hand can make the sudden expansion after the closure of the closure of the extension, from the destruction of the destruction of the location, so that the role away from the sealing surface; the other hand, increased the throttle resistance, reducing the degree of pressure recovery, Erosion weakened.
        Some of the valve seat hole designed to be stepped, wave type, is to increase the resistance, weaken the cavitation. This method is often used when the high pressure valve in the introduction device is used and the old valve is improved.
        6) change the flow to improve the life law
        The flow direction, the cavitation and erosion mainly act on the sealing surface, so that the core of the spool and the valve seat sealing surface are quickly damaged; the flow closure is directed to the direction of flow, cavitation, erosion After throttling, the valve seat sealing surface below, to protect the sealing surface and spool root, extended life.
        Pretending to open the use of the valve, when the extension of the life of the problem is more prominent, just change the flow can extend the life of 1 to 2 times.
        7) use special materials to improve the life method
        For anti-cavitation (broken shapes such as honeycomb dots) and scouring (streamlined trenches), throttle pieces can be made with special materials that are resistant to cavitation and erosion. This special material is 6YC-1, A4 steel, the Secretary too Lai, carbide and so on.
        For corrosion resistance, you can switch to more corrosion-resistant, and have a certain mechanical properties, physical properties of the material. This material is divided into non-metallic materials (such as rubber, PTFE, ceramics, etc.) and metal materials (such as Monel, Hastelloy, etc.) two categories.
        8) change the valve structure to improve the life method
        To change the valve structure or use a longer life valve approach to achieve the purpose of improving life, such as the use of multi-stage valve, anti-cavitation valve, corrosion-resistant valve.
        9) reduce the stroke to improve the diaphragm life method
        For the two-position control valve, when the frequency is very frequent, the diaphragm will soon be broken up and down in the fold, the destruction of the location often in the tray circumference.https://www.dragonapkpump.wordpress.com
        The easiest and most effective way to improve the life of the diaphragm is to reduce the stroke. The reduced stroke value is 1 / 4dg. Such as dgl25 valve, the standard stroke of 60mm, can be reduced to 30mm, reduced by 50%.
        In addition, the following factors can be considered:
        To meet the open and closed conditions to minimize the membrane chamber pressure;
        Improve the finish of the tray and the film