1. The opening and closing parts used by the globe valve are plug-shaped discs, which are divided into flat and conical surfaces on the sealing surface, and the discs move linearly along the center line of the fluid. The movement form of the valve stem includes a lifting rod type (the valve stem is raised and lowered, and the hand wheel does not rise), and there is also a lifting rotary rod type (the hand wheel and the valve stem rotate and rise together, and the nut is set on the valve body).
2. The stem axis of the globe valve is perpendicular to the sealing surface of the valve seat. The medium flow direction of the shut-off valve is changed to enter the valve cavity from above the disc. At this time, under the action of the medium pressure, the force to close the valve is small, while the force to open the valve is large. The opening or closing stroke of the valve stem is relatively short. Once the shut-off valve is in In the open state, there is no more contact between its valve seat and the sealing surface of the disc, so its sealing surface has less mechanical wear and has a very reliable cut-off action. Since most of the valve seats and discs of the globe valves are easier to repair or replace the sealing elements, the entire instrument valve does not need to be removed from the pipeline. This is very suitable for applications where the instrument valve and the pipeline are welded together.
3. In general, the function of the shut-off valve is only fully open and fully closed, that is, the cut-off function, but some variants of the shut-off valve, through some structural changes, can also achieve the role of adjustment and throttling.
According to the flow direction
1. Straight-through globe valve
The medium inlet and outlet channels are in the same direction and are 180°, the flow state is less damaged, and the pressure loss through the valve is relatively small.
2. Direct current globe valve
The valve stem and the passage form a certain angle, and the valve seat sealing surface and the inlet and outlet passages have a certain angle. The fluid hardly changes the flow direction, which is the smallest flow resistance in the stop valve. Suitable for pipelines with coking and solid particles.
3. Angle globe valve
The medium inlet and outlet channels are not in the same direction, and are at an angle of 90°, which will produce a certain pressure drop. The biggest advantage is that it can be installed at the bend of the piping system, which saves elbows and is convenient for operation.
According to the application
1. Fluorine-lined globe valve
Fluorine-lined valve, also known as fluoroplastic-lined corrosion-resistant valve, is to place PTFE resin (or profile processed) on the inner wall of a steel or iron valve pressure part by molding (or inlay) (the same method It is suitable for the inner lining of all kinds of pressure vessels and pipeline accessories) or the outer surface of valve inner parts. It is made into various valves and pressure vessels with its unique performance in resisting strong corrosive media. With the rapid development of modern industry, fluorine-lined valves and their various pipeline accessories have been rapidly applied and promoted in various fields such as petroleum, printing and dyeing, chemical engineering, etc., showing strong vitality, and being the first-choice project in engineering has caused various projects The great attention and favor of design units and construction units is a sunrise product with great market potential.
Fluorine-lined globe valve Fluorine-lined globe valve is suitable for various concentrations of aqua regia, sulfuric acid, hydrochloric acid, hydrofluoric acid and various organic acids, strong acids, strong oxidants, and also suitable for various concentrations of strong alkalis Organic solvents and other corrosive gases and liquid media are used in pipelines.
2. GB globe valve
The national standard globe valve is the most commonly used product in the globe valve series. The API American standard globe valve American standard globe valve implements ANSI and API standards. The sealing surfaces of the disc and the seat are made of stellite cobalt-based cemented carbide with different hardness. It is made of reliable sealing, high hardness, wear resistance, high temperature resistance, corrosion resistance, good scratch resistance and long life. Needle valve Needle valve is a small-caliber instrument valve, which plays a role of opening and closing and precise flow control in the instrument measuring pipeline system. It mainly includes power station instrument series, oil field special series, American standard series, etc.
3. Welded needle globe valve
Cryogenic globe valve Cryogenic globe valve Cryogenic globe valve usually refers to the valve whose working temperature is lower than -110℃, which is widely used in liquefied natural gas, liquefied petroleum gas and other cryogenic industries. At present, the globe valve with a suitable temperature of -196℃ can be manufactured, and all parts are pretreated with liquid nitrogen at low temperature, which completely avoids seal deformation and leakage during use.
4. Piston globe valve
The plunger valve is also known as the plunger stop valve. Its sealing surface adopts a radial sealing structure. The two elastic sealing rings sleeved on the polished plunger are applied to the valve cover through the connecting bolts between the valve body and the valve cover. The load compresses the elastic sealing ring around the plunger to achieve a sealed shut-off valve.
5. Insulation jacket globe valve
The insulation jacket cut-off valve adopts the insulation jacket design, using external heat source to circulate heating outside the valve, which can effectively prevent temperature loss when the medium passes through the valve and ensure the temperature of the medium.
6. Forged steel globe valve
The forged steel globe valve is designed and manufactured in accordance with API 602 standards, and provides three bonnet design forms: bolted bonnet, welded bonnet, and pressure self-tightening bonnet. Users can choose different forms according to their needs, providing RF flanges, There are three connection methods: NPT thread and SW welding type.
7. Oxygen globe valve
The oxygen-specific stop valve is made of silicon brass or stainless steel with excellent materials, which has the advantages of high mechanical strength, wear resistance, and good safety. Used in oxygen pipelines, it has the best explosion-proof and flame-retardant performance, eliminates the unsafe factors on the oxygen pipelines, and is widely used in the pipeline network of oxygen-consuming projects such as steel, metallurgy, petrochemical, and chemical industries. In addition to the functions of ordinary valves, it also has its own characteristics. Strict oil prohibition measures are adopted during manufacturing, and all parts are subjected to strict degreasing treatment before installation.
8. Bellows globe valve
The bellows stop valve adopts the design of formed stainless steel bellows. The bellows reciprocating test is 10,000 times without failure, and the sealing performance is reliable. It is suitable for industrial and mining with inflammable, explosive, toxic and harmful media, and can effectively prevent valve leakage.