The stop valve, one of the most widely used valves, works on the principle that the pressure from the valve stem causes the valve disc and the sealing surfaces of the valve seat to closely adhere together, thereby cutting off the flow of the medium. 

Its two core functions are one of truncation and the other of regulation. 

Cut off the flowing fluid 

It is like a safety switch in a piping system, capable of completely stopping the flow of the medium. Therefore, it comes in handy in scenarios such as urban water pipe maintenance and the control of toxic liquids in chemical plants. 

Adjust the flow rate 

The valve disc opening is in a fixed proportional relationship with the flow rate. Therefore, it is particularly suitable for situations where precise flow regulation is required, such as adjusting the water temperature in heating systems or controlling the dripping speed of reagents in laboratories. 

It also has a very practical function, which is to prevent backflow. Because the fluid pressure can tightly press the valve disc against the valve seat, creating a self-locking effect, this can prevent the medium from flowing in the reverse direction. This is very common in hydraulic systems. 

Where exactly is it used? 

High-temperature and high-pressure pipelines, such as those in thermal power plants, nuclear power plants, and petrochemical systems. 

Pipelines with low requirements for pressure loss. 

It requires flow or pressure regulation, but the precision requirement is not high, and the pipe diameter is below 50mm. 

In urban construction, water and heat supply pipelines with a diameter of less than 150mm. 

Its advantages are quite remarkable: 

The structure is simple, and both manufacturing and maintenance are quite convenient. 

Good sealing performance. 

The opening and closing stroke is very short. 

Of course, it also has its own weaknesses: 

The fluid resistance is relatively high. 

The opening and closing torque is also relatively large. 

It is not suitable for situations where frequent adjustments are required or where the viscosity of the medium is very high, such as honey and mud. 

Finally, when using it, there are a few points that you should pay special attention to: Avoid keeping it in a partially open state for a long time, as this will accelerate the wear of the sealing surface. 

When installing, you must pay attention to the flow direction. Generally, it follows the principle of "low inlet and high outlet". Installing in the reverse direction may cause leakage or make the operation difficult. 

Fully open or fully closed are the optimal states, while the intermediate state is only used for temporary adjustment.