The usage of fire damper, ball valve, safety valve and valve

Knowledge of fire valve and ball valve

There are several types of smoke exhaust fire damper: normally open smoke exhaust fire damper, normally closed smoke exhaust fire damper, remote control smoke exhaust fire damper (steel rope control type), automatic reset smoke exhaust fire damper. Let's introduce the functions of various smoke exhaust fire dampers.

1、 Function of normally open smoke exhaust fire damper:

1. Normally, it is normally open. When a fire occurs, the valve will be closed automatically after DC24V power is output by the control center.

2. When the pipe temperature reaches 280 ℃, the fuse acts and the valve will close automatically.

3. Output the valve closing signal and interlock the exhaust fan to stop.

4. Manual closing, manual opening.

2、 The normally closed smoke exhaust fire damper is also known as the function of the secondary action smoke exhaust fire damper:

1. Normally, it is normally closed. When a fire occurs, DC24V power supply is input by the control center, and the valve opens rapidly.

2. Output the valve opening signal and interlock to control the fire exhaust fan.

3. Manual opening, manual reset off.

4. When the pipe temperature reaches 280 ℃, the fuse acts and the valve is closed again.

3、 Function of remote control smoke exhaust fire damper (steel rope control type):

1. All functions of normally closed smoke exhaust fire damper

2. It can be opened manually from a long distance and closed manually.

3. The control distance of steel rope is 6m (super long can be customized)

4、 Automatic reset smoke exhaust fire damper:

1. Normally, it is normally closed. When a fire occurs, DC24V power supply is input by the control center, and the valve is opened automatically.

2. When the temperature of the pipeline reaches 280 ℃, the fuse acts and the valve will close automatically.

3. It can be opened manually.

4. After the valve is opened, it is unnecessary to reset manually. As long as the DC24V power supply is input, the valve can be automatically reset to the original closed position (this function is only limited to the function before the temperature sensor is not operated, if the temperature sensor needs to be replaced after the temperature sensor is operated, the function can be used).

5. Output the valve opening signal and interlock to control the start and stop of smoke exhaust fan.

6. If memory alloy temperature sensor is used, it can be used repeatedly without replacement.

Ball valve and plug valve are the same type of valve, only its closing part is a ball, the ball around the center line of the valve body to achieve the opening and closing of a valve. Ball valve is mainly used in pipeline to cut off, distribute and change the flow direction of medium. Ball valve is a new type valve widely used in recent years, which has the following advantages:

1. the resistance coefficient of the fluid is small, and the resistance coefficient is equal to that of the same length of pipe.

2. simple structure, small volume and light weight.

3. it is close and reliable. At present, the sealing surface materials of ball valve are widely used plastic and have good sealing property. It has also been widely used in vacuum system.

4. it is convenient to operate and open and close quickly. It can be controlled from full open to full close by 90 ° and convenient for remote control.

5. the maintenance is convenient, the ball valve is simple in structure, and the sealing ring is generally movable, and it is convenient to dismantle and replace it.

6. when fully open or fully closed, the sealing surface of the ball and seat is isolated from the medium, and the sealing surface of the valve will not be eroded when the medium passes.

7. it is widely used, with a diameter of from small to several millimeters, and from a large to a few meters, it can be applied from high vacuum to high pressure.

Ball valve has been widely used in petroleum, chemical industry, power generation, paper making, atomic energy, aviation, rocket and other departments, as well as people's daily life.

Ball valve can be divided into two parts according to the structure form:

1、 Floating ball valve

The ball of ball valve is floating. Under the action of medium pressure, the ball can produce certain displacement and press tightly on the sealing surface of outlet end to ensure the sealing of outlet end.

The structure of floating ball valve is simple and the sealing property is good. But the ball bears the load of working medium and passes to the outlet sealing ring. Therefore, it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium. This structure is widely used in low and medium pressure ball valves.

2、 Ball valve, fixed

The ball valve is fixed and does not move after pressure. Fixed ball valve has floating seat. After being under medium pressure, the valve seat moves, so that the sealing ring is pressed on the ball to ensure the sealing. Usually, bearing is installed on the upper and lower shafts with ball, and the operating torque is small, which is suitable for high pressure and large caliber valves.

In order to reduce the operating torque and increase the reliability of the sealing, in recent years, there are oil seal ball valves. Special lubricating oil is injected between the sealing surfaces to form a layer of oil film, which means that the sealing performance is enhanced and the operating torque is reduced. It is more suitable for high pressure and large diameter ball valves.

3、 Ball valve, elastic

The ball valve has a flexible ball. The ball and seat sealing ring are made of metal materials, with a high specific pressure. The pressure of the medium itself can not meet the requirements of sealing, and external force must be exerted. This valve is suitable for high temperature and high pressure medium.

Elastic sphere is to open an elastic groove at the lower end of the inner wall of the sphere, and obtain elasticity. When closing the channel, the wedge head of the stem is used to make the ball open and the seat pressed to reach the seal. Before turning the ball, loosen the wedge head, and the ball will return to its original shape, so that there is a small gap between the ball and the seat, which can reduce the friction and operating torque of the sealing surface.

Ball valve can be divided into straight, three-way and right angle type according to its channel position. The latter two ball valves are used to distribute and change the medium.