As the core component of fluid control system, the reasonable configuration of valves is directly related to the safety, efficiency and reliability of the system. With the continuous advancement of industrial technology, valves are diverse and have rich functions, which puts higher requirements on the scientific configuration of valves. This article aims to briefly introduce different valve configurations. By reasonably configuring valves, we aim to improve system performance and promote the development of industrial automation and intelligence.

Pressure reducing valve group configuration

Pressure reducing valve group: front and rear cut-off valves are installed before and after the pressure reducing valve, pressure gauges are installed outside the front and rear cut-off valves, and are bridged with bypass valves, a steam-water separation device is installed in front of the front cut-off valve, and a safety valve is installed after the rear cut-off valve.

Configuration of regulating valve group

Regulating valve group: front and rear cut-off valves are installed before and after the regulating valve, and bypass valves are used to bridge the front and rear cut-off valves. A check valve is installed between the front cut-off valve and the regulating valve. The bypass valve is used to temporarily adjust the flow when the regulating valve fails and is out of service. A stop valve, throttle valve (DN≤80) or gate valve (DN2100) should be used. The cut-off valve should be a gate valve to reduce flow resistance. The caliber of the regulating valve should be smaller than the caliber of the process pipeline, which is beneficial to reducing the project cost. Generally, 1/2~2/3 of the caliber of the process pipeline is taken. The larger the caliber, the lower the ratio should be. The regulating valve is a precision component and should be removed and replaced with a short pipe when the pipeline is purged.

Configuration of steam trap group

Steam trap group: Install front and rear cut-off valves before and after the steam trap (the rear cut-off valve is not necessary when the condensate is directly discharged into the atmosphere), install a vent valve in front of the front cut-off valve, install a filter between the front cut-off valve and the steam trap (thermodynamic steam traps do not need filters because they have their own filters), and install a check valve between the steam trap and the rear cut-off valve. The cut-off valve, vent valve, and check valve can be either stop valves or gate valves.

Configuration of flow meter valve group

Flow meter valve group: front and rear cut-off valves are installed before and after the flow meter, and bypass valves are used to bridge the front and rear cut-off valves. The front and rear cut-off valves use stop valves or gate valves, and the bypass valve uses a throttle valve to accurately adjust the flow.

Configuration of dual valve group

When it is necessary to strictly cut off the pipeline or equipment, you can consider using double valves, but they should be used as little as possible, especially stainless steel valves and large-diameter valves, to save costs. Double valves are generally configured on the sewage pipeline of industrial boilers. The sewage valve works frequently and is prone to leakage. In serious cases, the boiler will be forced to shut down. Replacing the sewage valve is troublesome and sometimes the boiler must be shut down. Configuring double valves can improve the shut-off performance and ensure the continuous operation of the boiler. The two sewage valves are installed in series, the one close to the boiler opens first and then closes, and the one far away from the boiler opens later and closes first. This operation method allows the high-speed liquid flow to only flush the valve far away from the boiler during sewage discharge, greatly extending the life of the valve close to the boiler. It may not be necessary to shut down the boiler when replacing the valve far away from the boiler. In some intermittent chemical production, if a certain medium leaks into the reaction, it may cause fire, explosion or other serious accidents. At this time, a double valve should be configured on the medium pipeline.

Configuration of auxiliary valve group

Some specific pipelines need to be equipped with auxiliary valves to solve some special problems. On the boiler steam outlet pipe and the workshop steam main pipe, when the steam valve is opened directly, due to the rapid heating of the pipeline, severe water hammer sound and strong vibration will be generated. At this time, a small bypass valve is connected in parallel next to the main steam valve. The bypass valve is opened before the main steam valve is opened. After the pipeline is preheated, the main steam valve is opened. The water hammer sound and pipeline vibration will be reduced a lot. Large-diameter gate valves, especially when used in pipelines with high pressure, are difficult to open due to the unilateral force on the gate plate. A small bypass valve is connected across the inlet and outlet of the gate valve. When the gate valve needs to be opened, the bypass valve is opened first, and the gate valve is opened after the pressure difference before and after the gate valve is reduced, which will save a lot of effort. Some valve manufacturers have already configured bypass valves when manufacturing large-diameter valves, such as large-diameter gate valves, large-diameter ball valves, and large-diameter check valves.