Detailed introduction of common valves of sewage treatment equipment

Detailed introduction of common valves of sewage treatment equipment

There are many kinds of valves used in sewage treatment equipment, such as gate valve, stop valve, butterfly valve, check valve, plug valve, throttle valve, safety valve and pressure reducing valve. Today, daze environmental protection will give you a brief introduction of several kinds. Please take notes!

1、 Gate valve

It is one of the most commonly used open / close valves. It uses the gate (i.e. the open / close part, in the gate valve, the open / close part is called the gate or gate, and the valve seat is called the gate seat or gate seat) to connect (fully open) and cut off (fully close) the medium in the pipeline. It is not allowed to be used as throttling, and the micro opening of the ram should be avoided in use, because the erosion of the high-speed flowing medium will accelerate the damage of the sealing surface. The gate valve is called gate valve because it moves up and down in the plane perpendicular to the center line of the gate seat channel and cuts off the medium in the pipeline like a gate.

2、 Stop valve

Stop valve is a closed-circuit valve that uses the valve disc (the closing part of the stop valve) to move along the center line of the channel of the valve seat (valve seat) to control the opening and closing of the pipeline. The stop valve is generally suitable for conveying liquid and gas media under various pressure and temperature conditions within the specified standard range, but it is not suitable for conveying liquids containing solid precipitation or precipitated crystals. In the low-pressure pipeline, the stop valve can also be used to adjust the flow of medium in the pipeline. Due to the limitation of structure, the nominal diameter of stop valve is less than 250mm. If it is on the pipeline with high medium pressure and high flow rate, its sealing surface will wear quickly. Therefore, when the flow needs to be adjusted, the throttle valve must be used.

3、 Butterfly valve

Butterfly valve is a rotary valve that uses the disc type (also known as butterfly plate) opening and closing parts to rotate about 90 ° or 90 ° to open and close the channel. The movement of butterfly valve disc is wiping, so most butterfly valves can be used for media with suspended solid particles.

4、 Check valve

The check valve is a valve used to prevent the backflow of medium in the pipeline. It opens when the medium flows downstream and closes automatically when the medium flows upstream. It is generally used in the pipeline that does not allow the medium to flow in the opposite direction to prevent the countercurrent medium from damaging the equipment and parts. When the pump stops running, it will not cause the rotary pump to reverse. In the pipeline, the check valve and closed-circuit valve are often used in series. This is because the tightness of the check valve is poor. When the medium pressure is small, a small part of the medium will leak, and a closed-circuit valve is needed to ensure the closure of the pipeline. The bottom valve is also a check valve, which must be submerged into the water and specially installed at the front end of the suction pipe of the water pump that cannot be self-priming or without vacuum pumping.

5、 Plug valve

Plug valve refers to a valve whose closing part (plug with channel) rotates around the center line of the valve body to open or close. It used to be called cock, also known as cork. It is widely used in medium pipelines with conveying temperature ≤ 120 ℃. Due to the thermal expansion of the plug and shell, jamming may occur, so it is rarely used at high temperature. The plug valve can be used to block the flow of medium, as well as regulating valve, three-way valve, four-way valve, distribution valve or change the flow direction of medium.