discount 70% in 2018-09-20 to 2018-09-22
price: USD$ 714.00
freight :USD$7.00,(Postal parcel)
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Product Name: thin Italian high platform ball 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 realistic function of ball valve
The working principle of ball valve is to make the valve unblocked or blocked by rotary valve. Ball valve switch light, small size, can be made into a large caliber, reliable sealing, simple structure, easy maintenance, sealing surface and sphere often closed state, not easy to be medium erosion, widely used in various industries.
Ball valve and plug valve belong to the same type of valve, only its closing piece is a sphere, the ball revolves around the centerline of the valve body to open, close a valve.
Ball valve in the pipeline is mainly used to do cutting, distribution and change the direction of media flow. Ball valve is widely used in recent years, a new type of valve, it has the following advantages:
1., the fluid resistance is small, and the resistance coefficient is equal to the pipe length of the same length.
2. simple structure, small size, light weight.
3., close and reliable, the ball valve sealing surface materials widely used in plastic, good sealing, vacuum system has been widely used.
4. has the advantages of convenient operation, open and close rapidly, from fully open to fully closed as long as the rotation of 90 degrees and facilitate remote control.
5. convenient maintenance, ball valve structure is simple, the sealing ring is generally active, disassembly and replacement are more convenient.
6. in the full open or full closed, the ball and seat sealing surface and media isolation, the media through, will not cause the valve sealing surface erosion.
7., a wide range of applications, diameter from a few millimeters, large to several meters, from high vacuum, high pressure can be applied.
Ball valve has been widely used in petroleum, chemical, power generation, paper making, atomic energy, aviation, rocket and other departments, as well as people's daily life.
Ball valve can be divided according to the structure:
Floating ball valve
Ball valve ball is floating, under the action of medium pressure, the ball can produce a certain displacement and tight at the outlet end of the sealing surface, to ensure that the export end seal.
The floating ball valve has the advantages of simple structure and good sealing performance, but the load of the ball bearing the working medium is all passed to the export sealing ring, so it is necessary to consider whether the sealing ring material can withstand the working load of the sphere medium. This kind of structure is widely used in medium and low pressure ball valves.
Two, fixed ball valve
The ball of the ball valve is fixed, and it does not move after compression. Fixed ball valve with floating seat, pressure by the media, the seat movement, so that the sealing ring is pressed on the sphere, to ensure 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 of the ball valve is elastic. Ball and seat rings are made of metal materials, sealing than pressure, relying on the pressure of the media itself can not reach the sealing requirements, must be applied to external force. This valve is suitable for high temperature and high pressure medium.
Elastic sphere is an elastic slot that is opened at the lower end of the inner wall of the sphere to obtain elasticity. When the channel is closed, the ball head is opened with the wedge head of the valve stem to seal the valve seat tightly. Before the ball is rotated, the wedge head is loosened, and the ball returns to its original shape, so that a small gap between the ball and the valve seat can reduce the friction and operation torque of the sealing surface.
Ball valve according to its channel position can be divided into straight through, three general and right angle type. The latter two ball valves are used to distribute the medium and change the flow direction of the medium.
Ball valve manual
1, scope:This manual is applicable to the electric (or pneumatic) ball valve at the flange connecting end.
2, composition:It consists of an electric (pneumatic) actuator (20) and a ball valve body, which is connected to a support (18) and a connecting shaft (17).
3, the use of restrictions:Temperature and pressure limits
The A. nameplate shows the maximum allowable operating pressure of the ball valve at the maximum and minimum operating temperatures.
B. use PTFE or RTFE seat and seal materials, operating temperature should be between-290c to 2000C. The operating temperatures of other types of seats and seals shall be checked by the KI plant.
The nominal pressure level (PN) of C. valve can indicate the maximum working pressure of the valve under normal temperature. (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 actuator matters needing attention, refer to the corresponding instructions.
1) remove the protective cover on both sides of the flange, and clean the valve in full open state.
2) before installation, the whole test should be carried out according to the specified signal (electricity or gas) (to prevent the vibration from affecting the performance), and the installation can be installed on line (wiring according to the circuit diagram of the electric actuator).
3) the remaining impurities in the clean pipe (which may damage the valve seat and ball) must be flushed and removed before they are ready to be connected to the pipeline.
4) during the installation, please do not use the actuator part of the valve as the lifting point of the lifting, so as to avoid damage to the actuator and accessories. .
5) this type of valve shall be installed in the horizontal or vertical direction of the pipe.
6) the pipeline near the installation point should not be lowered or subjected to external force, and the pipeline support or support can be used to eliminate the deviation of the pipeline.
7) after the connection with the pipe, please use the specified torque to cross lock the flange connection bolts.
5, operation and use
1) before the operation, it is necessary to confirm that the pipeline and valve have been flushed.
2) the operation of the valve drives the valve stem to rotate according to the input signal size of the actuator: when the positive rotation 1/4 circle (900), the valve is turned off. When the reverse rotating 1/4 ring (900) is opened, the valve opens.
3) when the actuator direction arrow is parallel to the pipeline, the valve is in open state; when the indicator arrow is perpendicular to the pipeline, the valve is closed.
Longer service life and maintenance free period will depend on the following factors: normal working conditions, maintaining a harmonious temperature / pressure ratio, and reasonable corrosion data
Note: the ball valve is still in the closed state, there is still pressurized fluid
Before maintenance, relieve the pipeline pressure and make the valve in the open position
Before maintenance, disconnect the power supply or gas source
Before the maintenance, the actuator is separated from the bracket
1) the packing must be locked again
L if there is a slight leak in the packing culvert, the valve stem nut (13) must be locked again
L pay attention not to lock too tight, usually lock 1/4 circle to 1 circles, leak will stop.
2) replace seat and seal
L make the valve in the semi open position, flush and remove the dangerous substances inside and outside the valve body
L closes the ball valve, removes the connecting bolts and nuts on both sides of the flange, and then removes the valve completely 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 connection bolts (5) and nuts, separate the valve cover from the valve body, and remove the valve cover gasket (16).
L confirm the valve ball (3) in the "turn off" position, which can be easier to take out from the valve body, and then take out 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)
Caution: be careful to avoid scratching the sealing surface of the stem surface and the stuffing box of the valve body
B) and reassembly
L cleaning and inspection of parts removed, it is strongly recommended to use spare parts package replacement valve seat and valve cover gasket and other seals
The L is assembled in reverse order of disassembly.
L uses the specified torque to cross lock the flange connection bolts (5).
L with the specified torque, lock the stem nut (13)
After installing the actuator, l input the corresponding signal, through the rotating stem to drive spool rotation, so that the valve to open and close position.
L if possible, the pressure seal test and performance test shall be carried out according to the relevant standards before the return piping.
Classification and characteristics of ball valves
Ball valve has O type ball valve and V type ball valve. 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: carbon steel ball valve, stainless steel 304 ball valve, 316 ball valve and copper ball valve
With applications, can be divided into: high pressure ball valve and low pressure ball valve
High pressure ball valve: mainly used in petroleum, natural gas, hydraulic oil, construction machinery and other industries
Low pressure ball valve: mainly used in the medium for water and other non corrosive pipeline!