discount 70% in 2018-09-22 to 2018-09-24
price: USD$ 2170.00
freight :USD$7.00,(Postal parcel)
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Product Name: thin Italian high valve
Connection: flange nominal diameter: 1/2 "-4". Applicable medium: water, oil, steam pressure range: 1.6,2.4,6.4 (Mpa). Suitable temperature: -40~150 (C). The opening and closing force of the N:300-400. main material: 304 and 316.: the design and production of international standards, ISO, API, GB. BS standard design and production, its safety and quality are strictly handle the payment of domestic and foreign markets.
The working principle and practical effect of ball valve
The working principle of the valve by rotating the valve to the valve flow or occlusion. Valve switch light, small size, can be made large caliber, reliable sealing, simple structure, easy maintenance, sealing surface and spherical often in the closed state, the media can not easily be eroded, widely used in various industries.
Ball valve and plug valve is the same type of valve, only its closure is a sphere, the sphere rotates around the body center line to achieve the opening and closing a valve.
The direction of flow valve in the pipeline is mainly used for cutting, distribution and change of medium. The ball valve is a new valve widely used in recent years, it has the following advantages:
1. fluid resistance small, the drag coefficient and the length of the pipe with the same.
2. simple structure, small volume, light weight.
3. close and reliable valve sealing surface material widely used plastic, good sealing in the vacuum system has also been widely used.
4. easy operation, open and close rapidly, from fully open to fully closed as long as 90 degree rotation, facilitate remote control.
5. ball valve has the advantages of simple structure, convenient maintenance, seals are generally activities, removal of the replacement is more convenient.
6. in the fully open or fully closed, the ball and seat sealing surface and the dielectric isolation medium through, will not cause erosion of the valve sealing surface.
7. is suitable for a wide range, from small diameter to a few millimeters high, a few meters from the high vacuum high pressure can be applied.
The ball has been widely used in petroleum, chemical, power generation, paper, nuclear, aviation, rockets and other departments, as well as people's daily life.
Valve structure can be divided by:
A floating ball valve
Ball valve ball is floating in the medium under pressure, can produce some displacement of the sphere and pressed in the export side of the sealing surface, to ensure that the export side seal.
Floating ball valve of simple structure, good sealing, but the ball under the load of all media work to export ring, so to consider the ring material can withstand the work load of the media sphere. This structure is widely used in low-pressure valve.
Two, fixed ball valve
The ball valve is fixed, after the pressure does not move. Fixed with a floating ball valve ball valve seat, by the media pressure, the valve seat moves, the sealing ring is pressed on the sphere, in order to ensure the sealing. Usually with the ball in the upper and lower shaft with bearings, operating torque, suitable for high pressure and large diameter of the valve.
In order to reduce the valve operating torque and increase the reliability of the seal, valve seal has emerged in recent years, both the pressure injection of a special lubricant in the sealing surface, to form a layer of film that enhances the sealing, and reduce operating torque, more suitable for large-diameter high-pressure valve.
Three, elastic ball valve
The ball valve is flexible. The ball and seat sealing ring are metal materials, sealing pressure than the large, rely on the pressure of the medium itself is not up to the requirements of sealing, external force must be. This valve is suitable for medium high temperature and high pressure.
Elastic sphere is a flexible open slot in the sphere of the bottom wall, and get flexible. When the closed channel, with the stem of the wedge-shaped head to open up the ball with the valve seat to seal compression. Release the ball before turning the ball shaped head, with restoration of the original prototype, make a small gap between the ball and the valve seat sealing surface can reduce friction and operating torque.
Ball according to their channels can be divided into straight through position three and right angle type. After two kinds of ball valves for distribution of media and change the flow of media.
Manual ball valve
1, the scope of:This statement applies to the flanged end of the electric (or pneumatic) valve.
2, composition:By the electric (or pneumatic) actuator (20) and ball valve components, which are connected by the connecting shaft bracket (18) and (17).
3, use restrictions:The temperature and pressure limits
A. plate showing the maximum operating pressure valve to allow the maximum and minimum operating temperature.
B. use PTFE or RTFE seat and seal materials, operating temperature should be between-290c to 2000C. Other types of seat and seal the operating temperature, the check should be nuclear plant KI.
C. valve nominal pressure rating (PN), may indicate that the maximum working pressure of the valve in the normal temperature conditions. (for example: PN4.0, that its operating temperature in 290C to the maximum working pressure of 380C for 40Bar (4.0MPa)).
D. electric or pneumatic actuators note see corresponding instructions.
1), take off the protection on both sides of the flange end cover, valve in the fully open state to wash clean.
2), should be required before installation of the signal (electric or gas) for the whole test (to prevent the vibration generated due to the use of the transport properties), after passing the on-line installation (wiring by electric actuator wiring diagram).
3) prepared with the pipe connection, it shall be washed and cleaned of residual impurities in the pipeline (these substances may damage the valve seat and ball).
4), during installation, please do not use the valve actuator as the lifting of the lifting part, to avoid damage to the actuator and accessories. .
5), the valve should be installed in the pipeline horizontal direction or vertical direction.
6), the installation of the pipeline near the external force should not be lowered or the phenomenon, you can use pipe support or supports to eliminate the deviation from the pipeline.
7), and pipeline connection, please use the provisions of cross locking torque flange bolts.
5, operation and use
1), to confirm the piping and valves have been washed off before operation.
2), the operation of the valve actuator according to the size of the input signal to drive the valve stem rotation complete: forward rotation 1/4 circle (900), the valve off. Counter rotating 1/4 ring (900) when the valve opens.
3), when the actuator line parallel with the directional arrow when the valve is open; arrow and vertical lines when the valve is closed.
Have a longer service life and maintenance free period will depend on several factors: the normal working conditions, to maintain the harmony of temperature / pressure ratio, and reasonable corrosion data
Note: the valve in the closed state, the body still exist within the fluid pressure
The maintenance, and to relieve line pressure valve in the open position
The maintenance, disconnect the power supply or source
The maintenance, the executive body and the support from
1), then lock packing at
L if the stuffing at the micro leakage occurred, to lock the stem nut (13).
L do not lock tight, usually lock 1/4 ring to 1 ring, leaking will stop.
2), replacement of the valve seat and seals.
L the valve in a semi open position, flushing, clear body of dangerous substances that may exist inside and outside.
L close the valve, remove the bolts and nuts on both sides of the flange, and then completely remove the valve from the pipeline.
L order demolition drive - actuator (20) and the connecting bracket (18), and lockwashers (14), stem nut (13), butterfly spring (12), (11), Glam wear plate (10), stem packing (9)
L remove the body cover bolts and nuts (5), the valve cover and the valve body separation, and remove the valve cover gasket (16).
L confirmed that the ball valve (3) in the "off" position, which can be more easily from the body out, then remove the seat.
L by the hole in the body downward nudge stem (6) until it is completely removed, and then remove the O ring (8) and the filler (7)
Note: please be careful, to avoid scratching the stem surface and valve stuffing sealing parts
B), re assembly
L cleaning and check the removed parts, strongly recommend using spare parts to replace the bag valve seat and the valve cover gasket seals
L in the opposite order of disassembly assembly.
L with the specified torque, cross locking flange bolts (5).
L with the specified torque, locking nut (13)
L actuator installation, the corresponding input signal by rotating the valve stem drive rotation of the valve to open and closed position.
L if possible, install pipes in the back before, according to the standards of the valve sealing pressure testing and performance testing.
The classification and features of the valve
O type ball valve and ball valve of V type. O type structure with floating ball ball core for precision casting, chrome plated surface seat materials with PTFE, runner and pipe diameter the same flow capacity greatly, small flow resistance, closed without leakage, generally do switch valve, especially suitable for high viscosity, containing fiber and granular medium; V type ball valve with a fixed structure, the ball core is provided with V type incision, the ratio can be adjusted to approximate the flow characteristics such as the percentage of.
According to the different choice of pneumatic or electric equipment, composed of pneumatic valve and electric valve, such as pneumatic ball valve to be regulated to achieve proportional valve positioner, such as the electric ball valve to be regulated to achieve proportional selection of electric actuator or servo amplifier.
From the material, can be divided into: 304 stainless steel carbon steel ball valve, ball valve, ball valve and ball valve 316 copper
With the application, can be divided into: high pressure ball valve and pressure valve
High pressure ball valve: mainly used in petroleum, natural gas, hydraulic oil, engineering machinery and other industries
Low pressure valve: mainly used in the medium of water and other non corrosive pipeline!