Adjustment valve installation and method for improving life

Pay attention to the following issues during the installation of the regulating valve :
(1) Before the valve is installed, the dust accumulated during the storage of the valve must be carefully removed and kept clean during the installation process. Damage to the seat and trim due to dusty impurities. In order to protect the cleaning, it is usually possible to attach a cover to the end of the open flange which is not welded on the day.
(2) When the regulating valve is installed, the arrow on the valve body should be consistent with the flow direction of the medium.
(3) Regulating valves are precision components that will undermine normal operation if they are stressed by pipe deformation. Therefore, the flange and pipe installation should be vertical and positionally accurate to avoid deformation of the pipe. Well, the pipe should be properly supported to prevent it from bending and deforming under the weight of the valve.
(4) The regulating valve must be specially handled when welding to the pipe. If the control valve is not adequately welded to the pipe and the stress is not removed, deformation will occur. When welding, the welding slag must be strictly prevented from splashing into the valve. The presence of the welding slag will damage the performance of the valve. If the splash directly splashes on the valve core, it will directly affect the action of the regulating valve , and damage the valve core and the valve seat.
(5) When the pipeline is tested and blown out, the regulating valve should be removed and connected with the corresponding straight pipe section to prevent the welding slag, iron cutting and other debris from getting stuck between the valve core and the valve seat. The end of the flange of the removed regulator valve is tightly wrapped with plastic sheeting.

1) Extended working method

Let the regulator valve work as much as possible at the beginning of the Zui, such as 90%. Thus, cavitation, erosion, and the like occur on the head of the spool. As the spool is broken, the flow rate increases, and the corresponding valve is closed again. This is continuously destroyed and gradually closed, so that the entire spool is fully utilized. At the same time, the large throttle opening throttle gap is large, and the erosion is weakened, which is better than the beginning. Let the valve work in the middle opening and small opening to increase the life by 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 to increase the working opening and increase the pressure drop of the orifice plate after the life method valve; close the manual valve connected in series on the pipeline until the regulating valve obtains the ideal working opening. This method is very simple, convenient and effective when the valve selection is at a small opening.

3) Reduce the caliber to increase the working opening and improve the life method

The working opening is increased by reducing the diameter of the regulating valve . The specific methods are as follows: 1 change the valve of a small first diameter, such as DN32 to DN25; 2 the valve body does not change, replace the valve core with small valve seat diameter Seat. If a chemical plant is overhauled, the throttle dgl0 is replaced with dg8, and the service life is doubled.

4) Transfer damage location to improve life method

Transfer the severely damaged area to a secondary location to protect the sealing and throttling surfaces of the valve seat.

5) Growth throttling channel to improve life method

The growth throttle channel is simple to thicken the valve seat, allowing the seat hole to grow and form a longer throttle channel.

6) Change the flow direction to improve the life method

The flow-opening type flows toward the opening direction, and the cavitation and erosion mainly act on the sealing surface, so that the sealing surface of the valve core and the valve seat is quickly damaged; the flow-closing type flows toward the closed direction, cavitation and erosion. After throttling, below the seat sealing surface, the sealing surface and the root of the valve plug are protected, extending life.
7) Use special materials to improve life method

In order to resist cavitation (destruction of shapes such as honeycomb dots) and scouring (streamlined small grooves), special materials resistant to cavitation and erosion can be used to manufacture the throttle.

8) Change the structure of the regulating valve to improve the life method

The purpose of improving the life is to change the valve structure or to select a valve with a longer life, such as a multi-stage valve, an anti-cavitation valve, a corrosion-resistant valve, and the like.