1、 Be sure to check before installation
1. Carefully check and verify whether the valve model and specifications meet the drawing requirements.
2. Check whether the valve stem and valve disc open flexibly, and whether there is any jamming or tilting phenomenon.
3. Check if the valve is damaged and if the threads of the threaded valve are correct and intact.
4. Check whether the connection between the valve seat and valve body is firm, and whether the connection between the valve disc and the valve seat, valve cover and valve body, and the connection between the valve stem and valve disc.
5. Check whether the valve gasket, packing, and fasteners (bolts) are suitable for the requirements of the working medium properties.
6. Old or unused pressure reducing valves should be dismantled, and debris such as dust and sand should be cleaned with water.
7. Remove the sealing cap from the port, check the sealing degree, and ensure that the valve disc is tightly closed.
2、 Pay attention to the general regulations for installation
1. The installation position of the valve should not hinder the operation, disassembly, and maintenance of the equipment, pipeline, and valve body itself, while considering the aesthetic appearance of the assembly.
2. Valves on horizontal pipelines should be installed with the valve stem facing upwards or tilted at a certain angle, and should not be installed with the handwheel facing downwards. The valves, valve stems, and handwheels on high-altitude pipelines can be installed horizontally, and the opening and closing of the valves can be remotely controlled by a vertical chain.
3. Symmetrical arrangement, neat and beautiful; The valve on the riser should be operated with the valve handwheel at chest height, as long as the process allows. It is generally recommended to be 1.0-1.2m above the ground, and the valve stem must be installed in the direction of the operator.
4. Valves on parallel pipes should have consistent centerline elevations, and the clear distance between handwheels should not be less than 100mm; Valves on parallel horizontal pipelines should be installed in a staggered manner to reduce pipeline spacing.
When installing heavy valves on equipment such as water pumps and heat exchangers, valve brackets should be installed; When operating frequently and installing valves more than 1.8m away from the operating surface, a fixed operating platform should be provided.
6. If there is an arrow mark on the valve body, the direction of the arrow indicates the flow direction of the medium. When installing the valve, attention should be paid to making the arrow point in the same direction as the flow of the medium inside the pipeline.
When installing flange valves, ensure that the two flange end faces are parallel and concentric with each other, and do not use double gaskets.
When installing threaded valves, for ease of disassembly, one threaded valve should be equipped with a union. The setting of the union should consider the convenience of maintenance, usually the water flow first passes through the valve and then through the union.
3、 Pay attention to the following small details
1. The valve body material of the valve is mostly made of cast iron, which is brittle and therefore cannot be impacted by heavy objects.
2. When handling valves, it is not allowed to throw them casually; When lifting and hoisting valves, ropes should be tied to the valve body, and it is strictly prohibited to tie them to the handwheel, valve stem, and flange bolt holes.
3. Valves should be installed in the most convenient place for operation, maintenance, and repair, and are strictly prohibited from being buried underground. Valves on buried and underground pipelines should be equipped with inspection chambers to facilitate the opening, closing, and adjustment of valves.
4. The thread should be ensured to be intact and undamaged, and hemp, lead oil, or polytetrafluoroethylene raw material tape should be wrapped around the thread. When screwing, a wrench should be used to clamp the hexagonal valve body at one end of the pipe.
5. When installing flange valves, pay attention to tightening the connecting bolts diagonally, and use even force when tightening to prevent the gasket from deviating or causing deformation and damage to the valve body.
6. Valves should be kept closed during installation. For threaded valves closer to the wall, installation often requires removing the valve stem, disc, and handwheel before turning. When disassembling, the handwheel should be turned to keep the valve open before disassembling.