A. Before installation, be sure to pay attention to the inspection
1. Check carefully whether the valve model and specification meet the requirements of the drawings.
2. Check whether the valve stem and valve flap open flexible, there is no stuck and skewed phenomenon.
3. Check whether the valve is damaged and whether the thread of the threaded valve is correct and intact.
4. Check whether the combination of the valve seat and the valve body is solid, the valve flap and the valve seat, the valve cover and the valve body, the valve stem and the valve flap linkage.
5. Check whether the valve bedding, packing and fasteners (bolts) are suitable for the requirements of the nature of the working medium.
6.The old or long-shelved pressure reducing valve should be disassembled and cleaned with water for dust, sand and other debris.
7. Clear the cover of the through-port, check the sealing degree, and the valve must be closed tightly.
Second, pay attention to the general provisions of the installation
1. The location of the valve installation should not interfere with the operation, disassembly and maintenance of the equipment, piping and the valve itself, while taking into account the beauty of the assembly shape.
2. Horizontal pipeline valves, valve stem upward installation, or tilt a certain angle installation, not handwheel downward installation. The valve, stem and handwheel on the overhead pipeline can be installed horizontally, and the valve can be operated from a distance with a chain that hangs low.
3. Symmetrical arrangement, neat and beautiful; the valve on the riser, as long as the process allows, the valve handwheel to flush chest high most suitable for operation, generally 1.0-1.2m from the ground is appropriate, and the valve stem must be installed in the direction of the operator.
4. Side by side on the riser valve, the centerline elevation is best consistent, and the net distance between the handwheel is not less than 100mm; side by side on the horizontal pipeline valve should be staggered installation to reduce the pipeline spacing.
5. In the pump, heat exchanger and other equipment installed on the heavier valves, should be set up valve bracket; in the operation of frequent and installed in more than 1.8m from the operating surface of the valve, should be set up a fixed operating platform.
6. The valve body has an arrow mark, the arrow points to the direction of the flow of the medium. When installing the valve, care should be taken to make the arrow pointing in the same direction as the media flow in the pipeline.
7. When installing flanged valves, ensure that the two flange surfaces are parallel and concentric with each other, and do not use double gaskets.
8. When installing a threaded valve, a threaded valve should be equipped with a live connection for easy disassembly. The setting of the connection should consider the convenience of maintenance, usually the water flows through the valve first after the connection.
Third, pay attention to the following small details
1. The valve body material is mostly made of cast iron, which is brittle, so it should not be hit by heavy objects.
2. When handling the valve, do not allow hand-throwing; lifting, lifting the valve, the rope should be tied to the valve body, is strictly prohibited in the hand wheel, stem and flange bolt holes.
3. The valve should be installed in the most convenient place for operation, maintenance and maintenance, and is strictly prohibited to be buried underground. Directly buried and trench pipeline on the valve, should be set up to check the well room, so as to facilitate the opening and closing of the valve and adjustment.
4. It should ensure that the threads are intact, and wrap hemp, lead oil or PTFE raw material around the threads, and when screwing the buckle, it is necessary to use a wrench to catch the hexagonal valve body screwed into one end of the pipe.
5. When installing the flange valve, pay attention to tighten the connecting bolts along the diagonal direction, screwing with even force to prevent the gasket from running off or causing deformation and damage to the valve body.
6. The valve should be kept closed during installation. For the threaded valve near the wall, it is often necessary to remove the stem valve and handwheel to unscrew the valve during installation. When disassembling, the valve should be disassembled after the handwheel has been unscrewed to keep the valve open.
