Many valves are directional, such as globe valve, throttle valve, pressure relief valve, check valve, etc. If they are installed upside down, it will affect the use effect and life (such as throttle valve), or not work at all (such as pressure reducing valve), or even a hazard (such as a check valve). Generally, the valve has a direction signs on the valve body; if not, it should be correctly identified according to the working principle of the valve. The valve cavity of the globe valve is asymmetrical, and the fluid should pass through the valve port from bottom to top, so that the fluid resistance is small (determined by the shape), and the opening is labor-saving (because the pressure of the medium is upward), and the medium does not press the packing after closing, which is convenient for maintenance. . This is the reason why the globe valve cannot be reversed. Other valves also have their own characteristics.
The position of valve installation must be convenient for operation; even if the installation is temporarily difficult,it is necessary to consider the long-term work of the operator. It is best to align the valve handwheel with the chest (usually 1.2 meters away from the operating floor), so that it is easier to open and close the valve. The handwheel of the landing valve should be upward, not inclined, so as to avoid awkward operation. The valve of the machine against the wall should also leave room for the operator to stand. It is necessary to avoid operation in the sky, especially acid-base, toxic media, etc., otherwise it is very unsafe.
The gate valve should not be installed upside down (that is, the handwheel is downward), otherwise the medium will remain in the bonnet space for a long time, which is easy to corrode the valve stem, and is prohibited by certain process requirements. It is extremely inconvenient to replace the packing at the same time. The rising stem gate valve should not be installed underground, otherwise the exposed valve stem will be corroded due to moisture.
When installing the lift check valve, ensure that its disc is vertical so that it can be lifted flexibly. When installing the swing check valve, ensure that the pin and shaft is horizontal so that it can swing flexibly.
The pressure relief valve should be installed in an upright position on a horizontal pipeline, and should not be tilted in any direction.
