If the valve is closed more quickly, the pipeline will experience sudden vibrations that produce loud noises. Please help analyze the reason for this
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Here’s a brief overview: There is a large tank that is cooled using a jacket; the coolant used is ethylene glycol. The inlet pipe is a main pipe with a diameter of DN100, equipped with a stop valve and a filter. There are four branch pipes: three with a diameter of DN50 and one with a diameter of DN32. Each branch pipe is fitted with angle valves and butterfly valves. Cooling is carried out in four stages； Return pipe: DN100 (equipped with a globe valve on the pipe). The corner valve is pneumatically controlled and belongs to the category of automatically controlled valves; when this valve is closed, a loud noise is produced in the pipeline ； When the manual butterfly valve is closed slowly, there is no noise, and everything is normal. Please help analyze the cause of the noise and how to resolve it Thank you!
Water hammer phenomenon: In pressurized pipelines, when the flow rate of water changes suddenly due to some external factor (such as a sudden closure of a valve or the sudden shutdown of a water pump), it causes alternating increases and decreases in pressure. This hydraulic phenomenon is known as water hammer. Rapid opening and closing of pumps, as well as too quick operation of gate valves, can cause sudden changes in water flow velocity. In particular, sudden shutdown of a pump can lead to water hammer, which may damage pipes, pumps, valves, and even cause the pump to run in reverse, resulting in a drop in pressure in the pipeline system. Therefore, it is extremely important to prevent water hammer from occurring. The main measures for preventing water hammer include the following:
a. Water hammer caused by too rapid opening and closing of valves:
(1) Extend the time taken to open and close the valves. (2) Centrifugal pumps and coagulation pumps should be stopped when the valves are closed at 15%-30% rather than fully closed. b. Water hammer caused by pumps (1) Remove the air from the pipeline, fill it with water before starting the pump; automatic air release valves should be installed at all elevated points in long-distance water transmission pipelines. (2) Pump shutdown water hammer is mainly caused by the rapid closure of the check valve on the outlet pipe; therefore, removing the check valve can eliminate the hazards associated with pump shutdown water hammer, as well as reduce head loss and save energy consumption ； Based on experiments conducted in some large cities, it is believed that the primary pump room can be eliminated, while the secondary pump room is not easily removable ； When removing check valves, it is necessary to perform calculations regarding the water hammer pressure. To reduce and eliminate water hammer, micro-resistance slow-closing check valves are commonly installed in large-diameter pipes nowadays. The use of buffer check valves and slightly closed butterfly valves installed on the outlet pipes of large-diameter pumps can effectively eliminate water hammer when the pump stops operating; however, since there is some backflow during the operation of these valves, an overflow pipe is necessary in the suction well. A water hammer arrester is installed immediately adjacent to the check valve and downstream of it.
a. Water hammer caused by too rapid opening and closing of valves:
(1) Extend the time taken to open and close the valves. (2) Centrifugal pumps and coagulation pumps should be stopped when the valves are closed at 15%-30% rather than fully closed. b. Water hammer caused by pumps (1) Remove the air from the pipeline, fill it with water before starting the pump; automatic air release valves should be installed at all elevated points in long-distance water transmission pipelines. (2) Pump shutdown water hammer is mainly caused by the rapid closure of the check valve on the outlet pipe; therefore, removing the check valve can eliminate the hazards associated with pump shutdown water hammer, as well as reduce head loss and save energy consumption ； Based on experiments conducted in some large cities, it is believed that the primary pump room can be eliminated, while the secondary pump room is not easily removable ； When removing check valves, it is necessary to perform calculations regarding the water hammer pressure. To reduce and eliminate water hammer, micro-resistance slow-closing check valves are commonly installed in large-diameter pipes nowadays. The use of buffer check valves and slightly closed butterfly valves installed on the outlet pipes of large-diameter pumps can effectively eliminate water hammer when the pump stops operating; however, since there is some backflow during the operation of these valves, an overflow pipe is necessary in the suction well. A water hammer arrester is installed immediately adjacent to the check valve and downstream of it.
The preliminary analysis indicates it’s water hammer; I’ve decided to try adding a resistor. Thank you all!
It’s the water hammer phenomenon; the 3rd floor post explained it in detail, so I won’t repeat it here
It’s the water hammer phenomenon. It’s recommended to install a device on the angle seat valve – an air supply throttle valve! QQ: 928976489
Could you send over a sample for me to take a look at? My email: zhouhw@gdecn.com
If it is a liquid pipeline, then water hammer has occurred； If it is a gas, it may be due to the energy released by throttling.