Valve is an attachment to open and close pipelines, control flow, regulate and control parameters (temperature, pressure, and flow) of the conveying medium.According to its functions, it can be divided into off -cut valves, stop valves, regulating valves, etc.Valve is a control component in a fluid conveyor system, which has functions such as deeper, regulating, diversion, preventing counter current, regulating voltage, diversion or overflow pressure.The valve for the fluid control system, from the simplest cut -off valve to the various valves used in extremely complicated self -control systems, has a variety of specifications and specifications.
What are the categories of valves?
(1) Treatment valve
This type of valve is closed and closed.It is often located on the cold, heat source entry, export, equipment in and exporting, and pipeline branches (including risers). It can also be used as a water leaving valve and a airworthiness valve.Common cutting valves include gate valves, interception valves, ball valves, and butterfly valves.
The gate valve can be divided into light rods and dark rods, single brakes and double gate, wedge -shaped gate and parallel gate.The closing valve is not close to the strictness, and the large diameter gate valve is difficult to open;
The deadlines are divided into three types: direct, right -angle, and DC formula according to the medium.The closure of the cut -off valve is better than the gate valve, long valve body, and large flow resistance. The largest nominal diameter is DN200.
The valve core of the ball valve is the open ball.When the dynamic valve stems make the sphere open the pipe axis, it is fully opened when the pipeline axis, and 90 ° is fully closed.The ball valve has a certain adjustment performance, which is tightly closed.
The valve core of the butterfly valve is a circular valve plate, which can rotate along the vertical axis of the vertical pipeline axis.When the plane of the valve plate is consistent with the axis of the tube, it is full; when the gate plane is vertically vertical and the pipe axis, it is full closed.The butterfly valve has a small body length, small flow resistance, and higher price than gate valve and deeper valve.[1]
(2) Stop valve
This type of valve is used to prevent the medium from reflecting, and use the fluids own kinetic energy to open it by itself, and automatically close it when the reverse flow.The exit of the pump, the export of a hydropower, and other places where the fluid is not allowed to flow.The stop valve spin -up, lifting and pairing type.For the rotating backbone valve, the fluid can only be automatically closed when flowing from left to right.For the lifting valve, when the fluid flows from left to right, the valve core is lifted to form a pathway. When the reverse flow flows, the valve core is pressed tightly to the valve seat and is closed.For the clamp -type stopping valve, when the fluid flows from left to right, the valve core is turned on to form a path. When the reverse flow flows, the valve core is pressed to the valve seat and is closed.Installation, small size, light weight, and compact structure.[1]
(3) adjustment valve
When the valve has a certain pressure difference, when the opening of the ordinary valve changes in a large range, the flow changes greatly, and when a certain degree of opening, the traffic changes sharply, that is, the adjustment performance is not good.The regulating valve can change the valves resistance number of the valve according to the direction and size of the signal to change the valve of the valve to achieve the valve that regulates the flow of flow.The regulating valve breakfast valve and automatic regulating valve, and the manual or automatic adjustment valve is divided into many types, and its adjustment performance is also different.The automatic regulating valve has a self -force flow regulating valve and a self -force pressure deviation valve.[1]
(4) Real category
Vacuum categories include vacuum ball valves, vacuum baffle valves, vacuum inflatable valves, pneumatic vacuum valves, etc.Its role is to change the direction of the air flow in the vacuum system, adjust the size of the air flow, and the vacuum system element that cuts or connects the pipeline is called a vacuum valve.
(5) Special use category
Special uses include pipeline valve, empty valve, sewage valve, exhaust valve, filter, etc.
The exhaust valve is an indispensable auxiliary element in the pipeline system. It is widely used in boilers, air conditioners, petroleum and gas, and water supply drainage pipes.It is often installed in a height or elbow, eliminating excess gas in the pipeline, increasing the efficiency of roads in the pipeline, and reducing energy consumption.
How to maintain valve
1. The valve should store the dry and ventilated room, and the two ends of the path must be blocked.
2. Long -term storage valve should be checked regularly to remove dirt and apply rust oil on the processing surface.
3. After installation, check the inspection regularly, and the main inspection items should be checked:
(1) Covering wear.
(2) The trapezoidal thread wear of valve stems and valve stems.
(3) Whether the fillers are out of date, and if there is damage, it should be replaced in time.
(4) After the valve inspection and assembly are repaired, the sealing performance test should be performed.
The valve in the operation should be complete and intact.The bolts on the flange and bracket are indispensable, and the thread should be intact, and there is no loose phenomenon.The tight nut on the hand wheel should be tightened in time if it is found to avoid wear or loss of the hand wheel and nameplate at the connection.If the hand wheel is lost, it is not allowed to replace it with a live wrench.The filler cover is not allowed to skew or has no pre -tight gap.For valves in the environment that is vulnerable to rain, dust, dust, wind and sand, etc., the valve stem must be installed with a protective cover.The scale on the valve should be complete, accurate, and clear.The lead seal, cover, and pneumatic attachment of the valve should be complete.There should be no depression or cracks in thermal insulation.It is not allowed to knock on the valve, stand or support heavy objects; especially non -metal valves and cast iron valves, it is also prohibited.
Lipidity maintenance maintenance
Professional maintenance of valve professional maintenance before welding and post -production plays a vital role in serving the valve to serve the production and operation. Proper and orderly and effective maintenance will protect the valve, so that the valve can be played normally and extend the valve use.life.Valve maintenance work seems simple, but it is not.There are often neglecting aspects in work.
First, when the valve is injected, the problem of lipid injection often ignores the amount of lipid injection.After the liposuction gun is refueling, the operator selects the valve and the liposuction connection method to perform lipid injection operations.There are two cases: on the one hand, the amount of liposuction is insufficient, and the cover surface is accelerated due to the lack of lubricants.On the other hand, excessive liposuction causes waste.It is not accurately calculated on different valve seal capacity according to the valve type category.You can calculate the sealing capacity in the valve size and category, and then reasonably inject the appropriate amount of lubricating fat.
Second, when the valve is injected, the pressure is often ignored.During the liposuction operation, the liposuction pressure changes regularly.The pressure is too low, the seal leakage or failure, the pressure is too high, the liposuction mouth is blocked, the sealing lipids harden, or the sealing ring and the valve ball and the valve board.Generally, when the pressure of liposuction is too low, the inflow of the lubricating fats is often inflow into the bottom of the valve cavity, which usually occurs at a small gate valve.The pressure of liposuction is too high. On the one hand, check the lipid mouth, if the lipidhole blocks the judgment and the situation is replaced; on the other hand, lipid -type sclerosis is used, repeatedly soften the sealing fat, and inject new lubricating fat replacementEssenceIn addition, the sealing model and sealing material also affects the pressure of liposuction. Different sealing forms have different liposuction pressure. Generally, the pressure of hard sealing liposuction is higher than the soft seal.
Third, when the valve is infused, pay attention to the problem of the valve in the switching position.During the maintenance of ball valve maintenance, it is generally in the open position, and under special circumstances, choose to close the maintenance.Other valves should not be the first place.The gate valve must be closed during maintenance to ensure that the lubricating fat is filled with a sealing groove along the sealing ring. If the position is opened, the sealing fat will directly fall into the flow tract or valve cavity, causing waste.
Fourth, when the valve is injected, the problem of liposuction is often ignored.The pressure, liposuction, and switching position in lipid injection operations are normal.However, in order to ensure the effects of the valve liposuction, sometimes it is necessary to open or close the valve to check the lubrication effect, and confirm that the valve valve ball or gate surface is lubricated evenly.
Fifth, when injection of liposuction, pay attention to the problem of sewage of valve body and the problem of degradation.After the valve suppression test, the gas and moisture in the sealing cavity cavity are boiled due to the increased environmental temperature. When the fat injection is injected, the pollution is drained to facilitate the smooth progress of the lipid injection work.The air and water in the sealing cavity after lipid injection are fully replaced.The pressure of the valve cavity in time also guarantees the safety of valve use.After the lipid injection is over, be sure to tighten the sewage and depletion wire to prevent accidents from occurring.
Sixth, when injection of fat, pay attention to the problem of uniform fat.When normal lipid injection, the fat is the closest fat to the fat, then to the low point, and then to the low point.If there is no law or fat, it proves that there is a blockage and timely treatment is performed in a timely manner.
Seventh, the diameter of the valve should also be observed when the liposum is eliminated.For example, the ball valve, if there is an openness of the position, can adjust the open space limiter inward to confirm that the diameter is flat and locks.Adjust your limits must not only pursue the position of opening or closing, and consider the overall consideration.If the open position is flat and it is not closed, it will cause the valve to close.In the same way, the adjustment is in place, and the corresponding adjustment must be considered.Make sure the right -angle itinerary of the valve.
Eighth, after lipid injection, be sure to seal the lipid mouth.Avoid impurities from entering, or liposomal oxidation of liposomal oral liposuction.In order to apply it next time.
Ninth, when injection of fat, we must also consider specific problems in the order of oil products in the future.In view of the different quality of diesel and gasoline, the ability to wash and decomposition for gasoline should be considered.In the future valve operation, when encountering the gasoline segment operation, it is timely supplemented by lubricating fat to prevent wear.
Tenth, do not ignore the liposuction of the valve stem parts when the liposuction is injected.There is a sliding shaft cover or filler part at the valve axis, which also needs to maintain the lubrication state to reduce the friction resistance during operation. If the lubrication cannot be guaranteed, the torque is increased to wear the wear parts during the electric operation, and the power is switched when manual operation.
Eleventh, some ball valves are marked with arrows on the body. If there is no English FIOW handwriting, it is the direction of the sealing seat. It is not used as a medium to reference.Under normal circumstances, the two -seated ball valves have two -way flow.
The twelfth, when the valve maintenance, also pay attention to the water inlet in the electric head and its transmission mechanism.Especially rainwater in the rainy season.The first is to make the transmission mechanism or the transmission shaft rust, and the other is to freeze in winter.During the operation of the electric valve, the torque is too large, and the damaged transmission parts can make the motor empty or ultra -torque protection from jumping away.The transmission parts are damaged and the manual operation cannot be performed.After the ultra -torque protection action, manual operation cannot be switched, such as forcibly operating, which will damage the internal alloy parts.

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