Precautions for installing low-temperature long-stem valves
Thread Content
The low-temperature long-stem valves installed in the three devices recently have experienced leakage from the valve stem during use. Installation orientation—the valve stem is parallel to the ground. Is it caused by an installation error? Please give some guidance; the manufacturer recommends installing it perpendicular to the ground.
Follow what the manufacturer says. If there is still a leak, it must be a problem with the manufacturer’s sealing design.
Install horizontally; large-sized valve handwheels are heavy, and bending can easily cause leaks.
Low-temperature valves cannot be installed horizontally; the reason for using extended valve stems is to ensure that the valve stem packing operates at temperatures above 0 degrees. Therefore, ultra-low temperature valves must be installed vertically. The length of the extended valve stem varies depending on the diameter of the channel, so as to ensure that the low-temperature medium within the valve chamber reaches a temperature above 0 degrees by the time it reaches the valve stem packing.
If installed horizontally, the fluid medium flows directly to the valve stem packing box, affecting the seal
For valves used in low-temperature environments, an extended rod is installed, followed by the addition of a handwheel mechanism or actuator. This design is intended to prevent the medium at low temperatures from reaching the handwheel or actuator, as the seals and lubricants found in these components typically function under normal temperature conditions; low or high temperatures can cause them to fail, thereby preventing the handwheel and actuator from operating properly. It is precisely because this extension rod increases the lever effect of the gravity acting on the rod itself, the handwheel, and the actuator that horizontal installation leads to wear of the valve packing and shaft sleeves on the lower side, ultimately resulting in leakage. It has a greater impact on large-diameter valves. So it’s still installed vertically.
It is still recommended to install valves vertically on horizontal pipes~~
Placing the horizontal valve stem causes the seal ring inside the stem to freeze and lose its flexibility, thus preventing sealing. It is recommended to install the valve at an angle of at least 30 degrees upward horizontally. Ensure that the low-temperature medium does not come into contact with the seals