First, be sure to check before installation
- Check carefully that the valve type and specifications meet the drawing requirements.
- Check the valve stem and disc opening for flexibility, jamming and skewing.
- Check the valve for damage and whether the threaded valve thread is positive and intact.
- Check that the combination of the valve seat and the valve body is firm, the valve flap and the valve seat, the valve cover and the valve body, and the valve stem and the valve flap are coupled.
- Check that the valve gasket, packing and fasteners (bolts) are suitable for the nature of the working medium.
- The old or long-lasting pressure reducing valve should be disassembled, and dust, sand and other debris must be cleaned with water.
- Clear the port cover, check the degree of sealing, and the valve flap must be closed tightly.
Second, pay attention to the general provisions of the installation
- The position of the valve installation should not impede the operation, disassembly and maintenance of the equipment, the pipeline and the valve body itself, and the aesthetic appearance of the assembly should be taken into consideration.
- The valve on the horizontal pipe, the valve stem is installed upwards, or it is installed at a certain angle. Do not install the hand wheel downward. The valves, stems and handwheels on the high-altitude pipeline can be installed horizontally, and the valve is opened and closed remotely with a chain that is vertically lower.
- Arranged symmetrical, neat and tidy; the valve on the riser, under the premise of the process, the valve hand wheel is most suitable for operation with the chest height, generally 1.0-1.2m from the ground, and the valve stem must follow the operator Directional installation.
- The valves on the side-by-side pipe shall have the same centerline elevation and the clearance between the handwheels shall not be less than 100mm; the valves on the side-by-side horizontal pipes shall be staggered to reduce the pipe spacing.
- When installing heavier valves on pumps, heat exchangers, etc., valve brackets should be provided; when operating frequently and installed on valves more than 1.8m from the operating surface, a fixed operating platform should be provided.
- The valve body has an arrow mark on the valve body, and the direction of the arrow is the flow direction of the medium. When installing the valve, care should be taken to point the arrow at the same direction as the flow in the pipe.
- When installing the flange valve, ensure that the end faces of the two flanges are parallel and concentric with each other. Do not use double gaskets.
- When installing a threaded valve, a threaded valve should be equipped with a union for easy disassembly. The setting of the joint should consider the convenience of maintenance. Usually, the water flow passes through the valve and then passes through the joint.
Third, pay attention to the following small details
- The valve body material of the valve is mostly made of cast iron, which is brittle and therefore must not be hit by heavy objects.
- When carrying the valve, it is not allowed to throw it at hand; when lifting and lifting the valve, the rope should be attached to the valve body, and it is strictly prohibited to lie on the hand wheel, the valve stem and the flange bolt hole.
- The valve should be installed in the most convenient place for operation, maintenance and overhaul. It is strictly prohibited to be buried underground. The valves on the pipes directly buried and in the trench shall be inspected to facilitate the opening and closing and adjustment of the valves.
- The thread should be intact and wrapped around the thread, leaded with lead oil or wrapped with Teflon tape. When turning the buckle, use a wrench to clamp the hexagonal valve body screwed into one end of the pipe.
- When installing the flange valve, pay attention to tighten the connecting bolt in the diagonal direction. When the screwing is used, the force should be even to prevent the gasket from running off or causing deformation and damage of the valve body.
- The valve should remain closed during installation. For threaded valves that are closer to the wall, it is often necessary to remove the stem valve disc and handwheel to install. When disassembling, the handwheel should be turned to keep the valve open, and then disassembled.