For high temperature valves over 200℃, because they are installed at room temperature, after normal use, the temperature rises, the bolts are heated to expand, and the gap increases. Therefore, they must be tightened again, which is called "heat tight valve". The operator should pay attention to this work , Otherwise it is prone to leakage.
When the weather is cold, if the water valve is closed for a long time, the accumulated water behind the water valve should be removed. After the steam valve stops vaporizing, condensation should also be eliminated. There is a wire plug at the bottom of the valve to open the drain.
Non-metal valves, some are hard and brittle, and some are low in strength. During operation, the opening and closing force should not be too large, especially not too strong. Also pay attention to avoid collisions of items.
When the new valve is used, the packing should not be too tight to prevent water leakage, so as to avoid excessive pressure on the valve stem, accelerated wear of the signal solenoid valve, and difficult to start and close.
The quality of valve installation directly affects the use, so careful attention must be paid to the direction and position of the valve, valve construction operations, valve protection facilities, bypass and instrumentation, and valve packing replacement.
Orientation and location
Many valves have a guiding function, such as stop valves, throttle valves, pressure reducing valves, check valves, etc. If the inverted method is used, the service life (such as throttle valves) will be affected, or it will not work at all (Such as a pressure reducing valve), or even cause danger (such as a check valve). Ordinary valves, the valve body has direction signs; otherwise, it should be correctly identified according to the working principle of the valve.
The valve cavity of the shutoff valve is asymmetrical left and right. The fluid must pass through the valve port from bottom to top, so that the fluid resistance is small (determined according to the shape), and the opening is labor-saving (due to the upward pressure of the medium), and the medium does not press the packing after closing, which is convenient for maintenance. Therefore, the shut-off valve can not be installed for this reason. All other valves have their own characteristics.
The valve body installation position must be easy to operate; even if the installation is temporarily difficult, the long-term work of the operator of the single-control solenoid valve must also be considered. It is best that the hand wheel of the valve and the chest should be aligned (usually 1.2 meters from the operating ground), so that it is easier to open and close the valve. The ground valve hand wheel faces upwards and cannot be tilted to avoid unstable operation. The valve near the wall and the valve near the equipment should also leave room for the operator to stand. Should avoid working upside down, especially in acid, alkali or toxic media, otherwise it is extremely unsafe.
The gate valve cannot be inverted (ie, the handwheel is down), otherwise the medium in the bonnet space will exist for a long time, which is easy to corrode the valve stem, and is contraindicated by certain process requirements. Packing replacement is extremely inconvenient.