Is open stem gate valve more reliable than concealed stem?

In industrial pipeline systems, gate valves are key components for controlling fluid flow, among which rising stem gate valves and hidden stem gate valves are more common. So, are rising stem gate valves really more reliable than hidden stem valves?

From the perspective of structural principles, the thread of the valve stem of a rising stem gate valve is exposed, and the gate is driven to open and close by the lifting and lowering of the valve stem. This design makes the lifting position of the gate valve clear at a glance, and the operator can intuitively judge the on/off status of the gate valve. Moreover, the valve stem does not come into direct contact with the medium, avoiding corrosion of the valve stem threads by the medium and reducing the risk of gate valve jamming and inability to open and close normally due to thread damage. In long-term use, the reliability of gate valves is more guaranteed.

The thread of the valve stem of the concealed stem gate valve is set inside the valve body, and the movement of the gate relies on the combined action of the rotation and lifting of the valve stem. Although the structure of the concealed stem gate valve is relatively compact and occupies a small space, the valve stem is easily corroded by the medium due to long-term immersion. Once the valve stem thread is corroded, the gate valve will experience jamming during operation, and even fail to open and close normally, seriously affecting the reliability of the gate valve. In some highly corrosive chemical pipelines, the defect of hidden stem gate valves is particularly evident, while visible stem gate valves, with their external valve stems, can effectively avoid such problems.

However, the open stem gate valve is not without its drawbacks. Due to its structural characteristics, rising stem gate valves occupy more space than concealed stem gate valves. In some places with strict space requirements, the installation of rising stem gate valves may be limited. However, overall, in most conventional operating conditions, rising stem gate valves have significant advantages in reliability. It can not only display the switch status more accurately, but also reduce the probability of failure caused by medium corrosion, ensuring the long-term stable operation of the gate valve.

So, it cannot be simply stated that stem gate valves are necessarily more reliable than non stem gate valves, but in situations where higher reliability requirements and space conditions permit, rising stem gate valves are usually the better choice.