Is open stem gate valve or non rising stem gate valve used outdoors
date:2023-07-12 10:34
The opening and closing component of the gate valve is the gate, and the movement direction of the gate is perpendicular to the direction of the fluid. The gate valve can only be fully opened and fully closed, and cannot be adjusted or throttled. The gate has two sealing surfaces, and the two sealing surfaces of the commonly used mode gate valve form a wedge shape. The wedge angle varies with the valve parameters, usually 50, and is 2 ° 52 'when the medium temperature is not high. The gate of a wedge gate valve can be made into a whole, called a rigid gate; It can also be made into a gate that can produce slight deformation to improve its processability and compensate for the deviation of the sealing surface angle during the processing. This type of gate is called an elastic gate.
For valves installed in outdoor valve wells, it is recommended to use non rising stem gate valves. The use of rising stem gate valves has the following drawbacks:
1. When the valve is opened or closed, the valve stem needs to be raised or lowered, occupying a large amount of space. If the pipeline is not buried very deep, the valve well will hinder the opening of the valve. When the valve is opened, the valve well cover will not be covered or the valve cannot be fully opened.
2. After switching multiple times, the contact surface between the valve stem and the gland leaks severely, requiring frequent replacement of the packing.
3. If not frequently turned on and off, a portion of the valve stem will be exposed outside the valve body for a long time. In a humid environment of the valve well, this exposed valve stem is prone to oxidation, rust, and death. Once it needs to be turned off, it cannot be turned off. Otherwise, it is necessary to apply lubricating grease frequently. In short, the maintenance workload is large.
Non rising stem valves do not have these problems, and the probability of water leakage is also low. Of course, the maintenance workload is also small. For reference only.
The types of gate valves can be divided into wedge gate valves and parallel gate valves according to the sealing surface configuration. Wedge gate valves can also be divided into single gate valve, double gate valve, and elastic gate valve; Parallel gate valves can be divided into single gate and double gate types. According to the thread position of the valve stem, it can be divided into two types: gate valve and non rising stem gate valve.
