What is a gate valve

The type of gate valve, according to the sealing surface configuration can be divided into wedge-type gate valve and parallel gate valve, wedge gate valve can be divided into: single-pole, double-plate and flexible plate type; parallel gate valve Divided into single-gate and double-plate type. According to the stem of the threaded position can be divided into two types of gate valve and dark bar gate valve.

When the valve is closed, the sealing surface can only rely on the media pressure to seal, that is, rely on the media pressure to the gate of the sealing surface to the other side of the valve seat to ensure that the sealing surface of the seal, which is self-sealing. Most of the gate valve is forced to seal, that is, when the valve is closed, to rely on external force forced to the gate pressure to the valve seat to ensure that the sealing surface of the seal.

Gate valve with the stem with a straight line movement, called the lift bar gate valve (also called the gate valve). Usually in the lift bar with trapezoidal thread, through the top of the valve nut and the valve body on the guide groove, the rotary motion into a linear motion, that is, the operating torque into the operating thrust.

When the valve is opened, when the height of the gate is equal to 1: 1 times the diameter of the valve, the fluid channel is completely open, but this position can not be monitored during operation. The actual use of the stem is the vertex as a sign, that is, the location of the open, as its full open position. In order to consider the temperature changes appear locking phenomenon, usually in the open to the vertex position, and then back 1 / 2-1 circle, as the full valve position. Therefore, the valve fully open position, according to the position of the gate (ie stroke> to determine.

Some gate valve, stem nut set on the gate, hand wheel rotation to drive the stem rotation, leaving the gate to lift, this valve is called the rotary bar gate valve or called the dark bar gate valve.

Manual gate valve works:

Turn the handwheel through the handwheel and the stem of the thread into the retreat, lift or drop the valve plate connected to the valve stem to achieve the opening and closing effect

Gate valve has the following advantages:

Fluid resistance is small, the sealing surface by the media brush and erosion of small.

Open and close more effort.

Media flow is unrestricted, no spoiler, no pressure reduction.

Simple shape, short structure length, good manufacturing process, wide application.

The drawbacks of the gate valve are as follows:

Sealing between the easy to cause erosion and abrasion, maintenance more difficult.

Large size, open need some space, open and close a long time.

Structure is more complex.

Gate type, according to the sealing surface configuration can be divided into wedge-type gate valve and parallel gate valve, wedge gate valve can be divided into: single-gate, double-gate and flexible plate-type; parallel gate valve Can be divided into single-gate and double-plate type. According to the stem of the threaded position can be divided into two types of gate valve and dark bar gate valve.

Gate valve installation and maintenance should note the following:

Hand wheel, handle and transmission are not allowed to be used for lifting, and is strictly prohibited collision.

The double gate valve should be mounted vertically (ie, the stem is in the vertical position and the hand wheel is at the top).

Valve valves with bypass valves should be opened before opening the bypass valve (to balance the inlet and outlet pressure and reduce the opening force).

The gate valve with drive mechanism is installed according to the instruction manual of product.

If the valve is often used for switching, lubricate at least once a month.

Structural features:

For a long time the general use of the market gate valve leakage or rust phenomenon, the introduction of the European high-tech rubber and valve manufacturing technology produced by the elastic seat closure valve, to overcome the general valve seal bad, rust and other defects, The sealing valve uses the elastic gate to produce the slight elastic deformation compensation effect to achieve the good sealing effect, the valve has the switch light, the seal is reliable, the elastic memory is good and the service life and so on the remarkable merit. Can be widely used in tap water, sewage, construction, petroleum, chemical, food, medicine, textile, electric power, shipbuilding, metallurgy, energy systems and other pipelines as a regulator and shut-off device.

Gate valve construction (features):

Light weight: the body made of high-grade black cast iron, the weight of the traditional valve weight reduction of about 20% to 30%, easy installation and maintenance.

Flat gate: the traditional gate valve is often in the water after the washing tube because of foreign objects such as stone, wood, cement, iron, debris and other silt in the bottom of the groove, easy to cause close to the formation of water leakage phenomenon, Elastic seat seal valve at the bottom with the same pipe with the flat design, not easy to cause debris deposition, so that fluid unimpeded.

The overall package of plastic: the use of high-quality rubber plate for the whole body, outsourcing plastic, the European first-class rubber vulcanization technology makes the curing of the gate to ensure accurate geometric dimensions, and rubber and ductile castings and then firmly, Elastic memory good. water

Casting body: the valve body with precision casting, accurate geometry makes the valve body without any finishing to ensure that the valve seal.

Gate valve has the following advantages:

1, the fluid resistance is small, the sealing surface by the medium brush and erosion small.

2, opening and closing more effort.

3, the media flow is not restricted, no spoiler, do not reduce the pressure.

4, simple shape, short structure length, manufacturing process is good, for a wide range.

The drawbacks of the gate valve are as follows:

1, between the sealing surface can cause erosion and abrasion, maintenance more difficult.

2, larger size, open need some space, open and close a long time.

3, the structure is more complex.

Gate type, according to the sealing surface configuration can be divided into wedge-type gate valve and parallel gate valve, wedge gate valve can be divided into: single-gate, double-gate and flexible plate-type; parallel gate valve Can be divided into single-gate and double-plate type. According to the stem of the threaded position can be divided into two types of gate valve and dark bar gate valve.

Gate valve installation and maintenance should note the following:

1, hand wheel, handle and transmission are not allowed to make lifting, and is strictly prohibited collision.

2, double gate valve should be installed vertically (that is, the stem in the vertical position, hand wheel at the top).

3, with a bypass valve valve should be opened before opening the bypass valve (to balance the import and export pressure and reduce the opening force).

4, with the transmission mechanism of the gate valve, according to the provisions of the product manual installation.

5, if the valve is often used to switch, at least once a month lubrication.

Source: China Gate Valve Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)

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