Installation Instructions of Valves (Part One)

Directions and positions of valve installation
Many valves such as globe valves, throttle valves, relief pressure valves and check valves have directional characteristics. If a throttle valve is installed up side down or reversely, its effect and service life will be affected; if a relief pressure valve is not installed properly, it won't work; if a check valve is installed reversely, it will cause danger.

Generally, there will be directional signs on valve bodies. If there is no directional sign on the valve body, you should operate the valve based on the working principle of the valve. Cavities of check valves are asymmetric, so the fluid should pass the valve port from bottom to top. Thus, fluid resistance will be small, and it is determined by the shape; it's easy to open the check valve due to upward media pressure; the medium will not press the packing after the check valve is closed and it is easy to exam and repair the check valve. That is why a check valve should not be installed reversely. Other valves also have their own characteristics. For example, a track ball valve should be installed based on high and low pressure ends.

The valve must be installed in a position which is easy to operate the valve. Even if the installation is difficult, we should take into account the long-term operation of the operator. It's better to make the hand wheel of the valve and the operator's chest align so that the valve will be opened or closed easily. The valve which is on the ground should be installed with a hand wheel upward, and don't tilt the valve so as to easily operate the valve. For some valves, some space needs to be saved for the operator to stand.

Avoid raising your head to operate the valve, especially valves with acid or toxic media. Otherwise, it will not be safe for the operator.

Do not install a gate valve up side down, which means that the hand wheel is faced down. That will make the medium stay in the valve bonnet for a long time and the valve stem easily corroded. Besides, that is also a taboo for valves with a certain technique. Meanwhile, it's not convenient to replace the packing. Don't install gate valves with raising stems under the ground. Otherwise, the raising stem will be corroded due to moisture. Ensure that the valve clack of the lift check valve is vertical in order to lift or descend the check valve. Make sure that the pin of the swing check valve is horizontal so as to flexibly open and close the swing check valve when it is installed. A relief pressure valve should be vertically installed on the horizontal pipe, and do not tilt the relief pressure valve in all directions.