Views: 13 Author: Site Editor Publish Time: 2020-08-06 Origin: Site
Globe valves are mainly used for steam or other media that require throttling applications. The advantage of the valve seat design is that when it is connected to the valve seat downward, the shape of the ball is used to effectively cut the fluid upwards until the fluid is completely sealed on the surface of the valve seat. However, this does cause a greater pressure drop than the gate valve and causes turbulence in the pipeline.The diameter, pressure level and material selection of all globe valves are the responsibility of the user or system designer. The process system can provide advice in this regard, but the selection process is entirely the responsibility of the end user or plant operator. This article is all about the installation,operation, and maintenance of the globe valve.
The installation of globe valve
The opetation of globe valve
The maintenance of globe valve
Globe valves are unidirectional, that is, they can only direct fluid in one direction, under the flap. There is an arrow direction in the valve body, but it can be easily checked by looking at one end of the valve to see whether it is under the seat or above the seat. It is recommended that the valve be installed vertically so that the handwheel operation is at the top of the valve. This ensures that the valve does not show premature wear or damage. The main installation points are as follows
(1) Remove any packing or debris from the globe valve
(2) Make sure there is no water or moisture inside the valve (heat will expand when starting)
(3) Ensure that the valve is in a supported state (if the valve is not supported by the pipeline for a long time, the valve may be damaged)
(4) Make sure there is enough space to operate the globe valve
(5) Make a complete drying cycle of the valve from closing to opening and then back
(6) Gradually tighten the flange bolts diagonally
(7) Gradually increase the internal pressure to ensure that the flange and bolts are installed correctly and the valve is well sealed
(8) Adjust the internal pressure to the working level and check again.
(1) Do not over tighten the seat to close. If the medium is still leaking, it may damage the valve seat
(2) Even if they are very suitable for controlling fluids, do not let the clapper stay in the middle of the fluid for a long time. This will cause premature wear of the valve seat. In steam applications where the continuous throttle opening is less than 10%, excessive vibration, noise, and wires passing through the valve seat can cause leakage paths that may sometimes not be visible to the naked eye.
(3) During operation, do not exceed 100% of the maximum rated pressure of the valve at any time. The pressure peaks or fluctuations beyond the rated pressure range of the valve are entirely the responsibility of the operator. If not observed, it may cause considerable injury or even death.
Regular maintenance and inspection plans will ensure that your globe valve has the best service life and operating performance. Here are some things to consider.
(1) Check the valve regularly. Pay special attention to the gland to ensure that there is no visible wear or valve leakage
(2) If the valve is not running regularly, it is best to circulate the valve to ensure that the disc is not seated on the seat
(3) Use a grease gun to apply oil to the provided grease nipple. If necessary, lubricate the spindle
(4) If the packing needs to be adjusted, tighten the gland bolts slightly. Do not over tighten, otherwise the gland will be damaged. If there is still leakage, you may need to replace the gland packing
Please pay attention to whether you want to remove the globe valve from the pipeline and check to ensure that there is no pressure on the pipeline and the valve has cooled to room temperature. Once removed, you can perform a complete inspection, including the ball (valve) and valve seat inspection. Any scale that accumulates on the bottom of the valve can be removed.