General requirements for valve installation

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The general requirements for valve installation, the most suitable installation height, the valve and valve stem direction on horizontal pipelines are as follows:: 1. The valve should be located in a place that is easily accessible, easy to operate and maintain. Valves on rows of pipes (such as pipes entering and exiting the device) should be arranged centrally, and operating platforms and ladders should be considered. When valves are arranged in parallel pipelines, their center lines should be as aligned as possible. The clear distance between handwheels should not be less than 10Qmm. In order to reduce the distance between pipes, the valves can be staggered. ； 2. The installation position of frequently operated valves should be convenient for operation. The most suitable installation height is about 1.2m from the operating surface. When the height of the center of the valve handwheel exceeds the operating surface by 2m, a platform should be set up for centrally arranged valve groups or individual valves that are frequently operated and safety valves. Appropriate measures should also be taken for individual valves that are not frequently operated (such as sprockets, extension rods, movable platforms and movable ladders, etc.). The chain of the sprocket should not obstruct traffic. Valves on pipelines and equipment for hazardous media must not be installed within the height of a person's head to avoid hurting the person's head or directly injuring the person's face due to valve leakage. ； 3. The valve used to isolate the equipment should be directly connected to the equipment pipe or close to the equipment. Valves on pipelines connected to equipment with extremely hazardous or highly hazardous toxic media should be directly connected to the mouth of the equipment, and the valves must not be operated by sprockets. ； 4. Accident handling valves such as fire water valves and fire steam valves should be arranged in a dispersed manner, and safe operation in the event of an accident should be taken into consideration. This type of valve should be arranged behind the control room. Behind the safety wall, outside the factory door, or at a certain safe distance from the place where the accident occurred ； So that in the event of a fire accident, operators can operate safely ； 5. Unless there are special requirements for the process, valves on the bottom pipes of towers, reactors, vertical vessels and other equipment must not be arranged in the skirt. ； 6. The cut-off valve of the horizontal branch pipe leading from the main pipe should be located on the horizontal pipe section close to the root. ； 7. Lift check valves should be installed on horizontal pipes, and vertical lift check valves should be installed on vertical pipes where the medium in the pipe flows from bottom to top. Swing check valves should be installed on horizontal pipes first, and can also be installed on vertical pipes where the medium in the pipe flows from bottom to top. ； The bottom valve should be installed at the standpipe end of the suction pipe of the centrifugal pump ； In order to reduce the installation height of the pump outlet cut-off width, a butterfly check valve can be used ； When the diameter of the pump outlet is inconsistent with the diameter of the connected pipe, a reducing check valve can be used ； 8. The distance between the center of the handwheel of the valves arranged around the operating platform and the edge of the operating platform should not be greater than 450mm. When the valve stem and handwheel extend above the platform and the height is less than 2m, they should not affect the operation and passage of the operator. ； 9. The valves of underground pipelines should be installed in the pipe trench or valve well, and if necessary, valve extension rods should be installed. Fire water valve wells should be clearly marked ； 10. For valves on horizontal pipelines, the direction of the valve stem can be determined in the following order: vertically upward ； level ； Tilt upward 45° ； Tilt down 45° ； Not vertically downward ； 11. For rising-stem valves with the valve stem installed horizontally, when the valve is opened, the valve stem must not affect the flow of traffic.