How to use the valve properly and maintain and repair it

How to use the valve correctly is the knowledge that the user must master. Only when it is used correctly can it be used for a longer period of time. Therefore, the center of the hydraulic control valve advises that the valve must be read carefully before installation and use, and it is strictly followed by the instruction manual of the valve. Operation and maintenance, negligence and recklessness are a major cause of valve damage.

We know that the amount of work that most valves require to repair is minimal, which means that most valves do not have to be repaired often. Sometimes, even a simple problem such as the leakage of a valve stem is often due to negligence. What is more, some reckless operators do not close the valve in accordance with the requirements of the technical specifications, resulting in severe damage to the valve stem or the closure. This happens from time to time.

The threaded joints of the stem nut and stem should be lubricated with oil regularly, which not only can reduce the friction between them, but also can prolong their service life. This is also a very important protection measure. If the worn stem nut is still in use, then there may be a breakage so that the entire axial force of the stem is not supported and the valve will lose its effect.

A simple leak at the beginning of the gasket finally reached the danger of steam leakage. To avoid this danger, when the leakage begins, the bonnet bolts should be properly tightened; if the valve seat sealing surface is not properly selected due to material selection, a small amount of leakage is started, which may later be extended to leaking grooves, and the opening height is not enough. This speeds up fluid erosion and results in complete damage to the valve seat.

The stem bending may be caused by the operator turning the handwheel too far after closing the valve.

There are many reasons for valve damage. In fact, if operators are slightly trained, similar situations may be avoided.

The use, maintenance and repair of several common valves are now described one by one.

Shutoff valve is a commonly used shut-off valve, mainly used to connect or cut off the medium in the pipeline. In the piping system, the time for not operating the cut-off valve is very small. Therefore, regular maintenance is required.

A small amount of packing leakage can be solved by simply tightening the packing gland nut. However, when the packing is damaged, the packing must be replaced. When replacing the packing, the valve must be fully opened to allow the upper seal to function (which is generally possible under pressure). Replace the packing box with a suitable packing and tighten the packing gland nut. Afterwards, check periodically to prevent loosening of the gland nut.

When replacing the valve parts, lift the stem, disassemble the valve cover, install a new disc on the new holder, turn the stem until the disc is disengaged from the holder, and use the new disc. And the holder is replaced and installed in the valve, and the operation of replacing the valve flap is convenient.

To polish the flap (abratable newer valve), use a small amount of abrasive on the flap and then grind it. The grinding method is to place a pin on the hole of the valve nut slot and the head of the valve rod, place the assembly on the valve body, unscrew the connection sleeve, and then perform grinding alternately. Use the valve stem as a grinding tool, add the abrasive, and grind it. The grinding should not be excessive. When grinding is complete, remove the abrasive and lubricate the threads.

The function of the check valve is to allow only one-way passage of the fluid to prevent back flow of the medium.

The most common urea device is a lift check valve. The valve flap moves up and down along the centerline of the channel. The action is reliable, but the fluid resistance is large. It is suitable for small and medium caliber occasions. Lift-type check valves can be divided into straight-through and vertical or angular. The straight-through lift check valve can only be installed in the horizontal pipeline, and the vertical lift check valve should generally be installed in the vertical pipeline, and the medium flows from bottom to top, and the angle lift check valve can only be installed vertically. The pipeline.

Special care must be taken when adjusting larger spring-loaded safety valves, because neither the user, the manufacturer, nor the repair shop has sufficient capacity to accurately verify the discharge pressure. Do not make any adjustments to the spring-loaded safety valve unless it is accurately adjusted at the manufacturer or on the actual device.