Marine Valves
Marine valve have DIN,JIS,CB,GB Standards
Butterfly valve is a simple structure control valve can be used for low pressure pipeline medium switch control butterfly valve is closed parts for the disc, around the valve axis of rotation to achieve valve opening and closing
Working principle
Butterfly board driven by the stem, if turn 90 degrees, can complete a opening and closing. Change the deflection angle of butterfly plate, can control the flow of medium.
Working condition and medium: butterfly valve used in furnace, gas, natural gas, liquefied petroleum gas, city gas, hot and cold air, metallurgical and chemical industry and environment-friendly power generation, building to drainage engineering system transport all kinds of corrosive and non corrosive fluid pipe for regulating and truncated medium flow.
Functional use:
Valve opening and closing parts is a round disc, in the valve body around its own axis rotation, so as to achieve the purpose of open and close or adjust. Butterfly valve fully open to fully closed is usually less than 90 degrees, the stem with worm gear reducer has self-locking capability.
Structure characteristics:
1.Simple structure, small size, light weight
2.Under low pressure, can achieve good sealing, good regulation performance
3.Butterfly plate of the streamline design, so that the loss of fluid resistance is small
4.Pole structure of the stem is through rod structure, after quenching, with good mechanical properties and corrosion resistance, scratch resistance.
Globe Valve is forced sealing valve, so valve closed must give the valve pressure to force the sealing surface leakage.
Globe valve closure principle, relying on the valve bar pressure, so that valve sealing surface and the valve seat sealing surface tightly, to prevent medium circulation.
Working principle and characteristic of globe valve
Globe valve on the pipeline medium plays the important role of the off and throttling, the sealing is by applying a torque to valve stem. stem in the axial direction to the valve pressure valve sealing surface and the valve seat sealing surface tightly, to prevent medium along the close gap between the cover leakage.
Globe Valve sealing from valve close cover and valve seat sealing surface formed. Stem drive the valve along centerline of valve seat for vertical movement. In the process of opening and closing the valve opening height is small, easy to adjust flow, and convenient maintenance, suitable for a wide range of pressure.
Characteristic
(1) the globe valve structure is simple, easy to manufacture and maintenance.
(2) the sealing surface is not easy to wear and abrasion, good sealing performance, long service life.
(3) when the opening and closing, the valve board trip small
(4) opening and closing moment big make it difficult, time cost much.
(5) the fluid resistance big, because the valve body medium channel tortuous, fluid resistance, power consumption cost high.
(6) the direction of medium flow nominal pressure PN is less than or equal to 16MPa, the medium flow direction from the valve flap down to up; nominal pressure PN is equal to or more than 20MPa, medium flow direction from the valve flap up to down. In order to increase seal. When using, the valve medium can only flow in one direction, and can not change the direction of flow.
(7) when the valve is fully open, the valve is often affected by erosion.
Check valve is rely on the medium flow automatically open and close the valve, is used to prevent the medium from back flow valve, belonging to an automatic valve, the main role is to prevent the medium back, to prevent reverse of pump and drive motor, and the container medium discharge.
Working principle
Check valve action is only to allow the medium flow in one direction, but also to prevent direction of the reverse flow. This valve is usually work automatically, under pressure of flow fluid in a direction, the valve flap to open; fluid flow in the opposite direction, by the fluid pressure and the valve flap weight of the combination role on the valve seat, thereby cutting off flow. Include check valves and lift check valves
Suitable occasion
Butterfly double disc check valves are used in high-rise building water supply pipe network, certain chemical corrosive medium pipeline, installation space network constraints, is suitable for the sewage pipe network.
Lifting type mute check valves are used to water supply and drainage engineering high quality requirements of network; network of relatively high pressure requirements, can be installed in the pump outlet, is economic and practical water hammer check valves.
Lifting type silencing check valve is used in water supply and drainage system, pipe network of high-rise buildings, installed in the pump outlet, by slightly modifying the structure, used as a suction end of the valve, but does not apply to the sewage pipe network.
Horizontal check valve is suitable for diving, drainage, sewage pump, especially suitable for sewage and sludge system.
Swing check valves are suitable for use in water pipe network of life, but it is not suitable for sediment
Single swing check valve is used in water supply system, petroleum, chemical, metallurgical and other industrial departments to have installed in the limited space of places is most applicable.
The moving direction of the gate valve is perpendicular to the direction of the fluid., gate valve only can be fully open and fully closed, discomfort door parameter varies, usually 5 degrees, medium temperature is not high for 20 52 '.
Advantage
Flow resistance is small, open and close more effort, the height of the great, open and close for a long time, water hammer phenomenon is not easy to produce medium can to both sides of the flow in any direction, the structure with a smaller length, and form a simple manufacturing process is good, has the advantages of compact structure, good rigidity of the valve, channel flow, flow resistance, the number is small
Working principle
Valve closed, the sealing surface can only rely on medium pressure to seal, which rely on medium pressure the gate sealing surface push to the other side of the seat to ensure the sealing surface of the self sealing. Gate valve with the valve stem together for linear motion. Usually in the lifting rod with trapezoidal thread, through valve nut the on the top of valve and guiding groove, make the rotary motion variable into linear motion, that is make the operating torque into thrust action. Open the valve, when the gate valve lift height is equal to 1:1 times the diameter, the fluid flow channel completely
Also called sea water inlet valve is installed on the ship port and starboard, light waterline bilge or the bottom of the hull. Through the hand wheel or deck transmission mechanism of opening and closing the valve, to control ship external water into the ship supply water for cleaning and cooling machine use.
Marine main engine to run need water cooling, Set high, low level submarine gate, suction water, provide engine cooling water.
Ball valve is defined as: opening and closing parts driven by the stem, and around valve axis for the rotation.
Features: wear resistant, good sealing performance; light switch; long life;
Advantages: fluid resistance is small; simple structure, small volume and light weight; tightness reliable; the rapid opening and closing; easy maintenance; the ball and seat sealing surface and the dielectric isolation; wide application range; because the valve in the open and close process of wiping, used with suspended solid particles of the medium;
Marine Plug valve
Plug valve is closed or plunger type rotary valve, make the channel port on the valve plug and the channel port on the valve body connect and separate by the rotated 90 degrees, valve open or close
Plug valve is suitable for cutting and connected to the streaming medium and application, but according to applicable properties and sealing surface erosion resistance, sometimes also can be used for throttling. Plug valves widely application in oil field exploitation, transportation and refining equipment, but also widely used in petrochemical, chemical, gas, natural gas, liquefied petroleum gas, HVAC industry and general industrial.
Marine Safety valve
Safety valve opening and closing parts under the action of external force in a normally closed state, when the equipment or pipeline medium pressure increases exceed the prescribed value through the medium to outside of system discharge to prevent piping or equipment in the medium pressure exceeds the set value of special valves. Safety valve is automatic valves, mainly used for boilers, pressure vessels and pipelines, control pressure does not exceed the specified value, plays an important role in the protection of personal safety and equipment operation. Note the safety valve must be tested in order to be used.
Main function:
Safety valve in the system play the role of security. When the system pressure exceeds the set value, open the safety valve, discharge gas / fluid of system in a portion into the atmosphere, system pressure does not exceed the allowable value, so as to ensure the system is not an accident because the pressure was too high.
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