Product features and uses:
This valve adopts double eccentricity soft seal structure, which absorbs the structure and characteristics of similar products from abroad, overcomes the defects existing in the use of the original product, makes its life more durable, and the sealing is more reliable. This valve is suitable for all kinds of pipelines, especially installed at the outlet of the circulating water pump, used for cutting off or regulating the flow of the medium, and can suppress the impact of the pump when it is started or stopped, and is not affected by the flow of the medium. Its structural features are: small size, light weight, compact structure, rapid opening, reliable sealing performance, light and labor-saving, long life and easy maintenance. The sealing ring is natural rubber. The valve body adopts carbon steel surfacing stainless steel, which has the advantages of reliable sealing.
Structure description:
The butterfly valve is a double eccentric soft seal structure, that is, the eccentric distance a from the rotary center of the butterfly plate to the sealing cross section of the valve body, and the distance b from the center of the butterfly plate to the center line of the valve body (see the following figure). The valve is decelerated by the worm gear (electric valve is decelerated by the motor through the worm gear), and the butterfly plate 2 is driven by the valve shaft 3 to rotate in the range of 90° C. so that the butterfly plate is opened or closed, and the purpose of connecting or cutting off the medium is achieved. . It is known from the drawings that when the valve is closed, the seal ring 4 is pressed by the valve body sealing surface 1 and the disc 2 to generate a deformation, so that the sealing force between the valve sealing surfaces gradually reaches a maximum value. Its features are:
With two-way sealing performance, it is especially suitable for working conditions where the medium has both forward flow requirements and reverse flow requirements.
The double-eccentric seal structure has a more closed and tight function when closed, and the sealing performance is reliable.
The valve stem adopts a half-axis structure, and the butterfly plate adopts a truss structure, which has high strength, large flow area and small flow resistance;
Replace the valve body material, seal ring is located on the butterfly board, replace the seal ring material, applicable to different media;
The worm gear is fully enclosed and can be used in long-term soaking water and is flexible in operation.
The electric device adopts the imported integrated product, which can be controlled locally or remotely and controlled safely and reliably.
Second, valve standards and performance test specifications
1, the standard specification (see sample)
2, performance test specifications (see sample)
Main part material (see sample picture)
Shipping and storage
1, preparation before transport
The valve end pasغير مجاز مي باشدes and the exposed surfaces of the valve stems are the key locations and the following measures should be taken:
The internal scale of the valve should be cleared to keep the valve cavity clean and dry.
The exposed surface of the valve should be coated with anti-rust oil.
The valve end should be protected against mechanical damage such as flanges.
Valve opening and closing parts should be closed.
2, handling
Care should be taken when handling the valve. The valve must not be thrown or dropped. In particular, the handwheel and valve stem should not be used as lifting or suspension points for large valves.
3, storage
The issues that should be noted for storage and transportation are usually the same as for transport preparation. However, the time factor is very important. Generally, the storage period of the butterfly valve is determined according to the shelf life of the sealing ring material. If the valve is to be extended for several weeks or months, the original storage conditions need to be improved. Valves are generally stored indoors so that the actual valve temperature is always above the dew point temperature. If the valve must be stored outdoors, it should be supported without contact with the ground and protected by a waterproof cover.
Sixth, install
1. The installation of the valve is the key to the service life of the valve. Improper installation may degrade valve performance. Therefore, the following points should be confirmed before installing the valve:
(a) Carefully dismantle the packaging of the valve, check the list of materials, specifications, schedules, etc., check the label or label to ensure that it meets the order requirements;
(b) must pay attention to the special warning label or sign attached to the valve or along with the valve and take appropriate measures;
(c) Check the sign indicating the flow direction of the valve. If the flow direction is marked, install the valve in accordance with the specified flow direction;
(d) Check the interior of the valve for cleanliness, presence of foreign material, and hazardous corrosion through the two ends of the valve. Removal of special packaging materials, such as preventing movement of the valve flaps during transport and handling;
(e) Before installing the valve, check that the pipe connected to the valve is clean and free from foreign matter.
Seven, test and adjustment
When the valve is strictly checked, however, the valve is at the last moment of danger. Only through the test to verify its operating performance.
At this time, the stem seal should be inspected to determine if the packing is properly installed and the packing gland bolt is in its initial position. When checking the operating performance of the valve and introducing the system's media pressure, additional adjustments should be made as needed. Observe by on-off or off-on cycle operation. If no obvious problem is found, the actual test can be performed with pressure while checking the sealing performance and operating performance. After installation, it should be in good working condition and ready for operation.
Eight, operation and maintenance
The valve is a special product that has both moving and wearing parts. In order to obtain satisfactory performance of the valve, it is necessary to protect the finished surface of certain parts for a long time.
Under normal operating conditions and pressure, medium, and temperature conditions, the continuous service life of the valve is not less than three years.
Power operated valve operation
Functionally speaking, the performance of the closure and the setting of the upper seal are mainly related to the valve type itself. Regardless of the operating mode, the power operated valve must be stored in the drive controller in order to obtain satisfactory results. In this way, the drive should be adjusted to deliver the proper opening, turning and closing forces to suit the intended operating conditions and the type of valve. Valves with relatively strict closing position requirements should be closed with position control, eg with external limit switches.
maintain
The valve is a hybrid structure of the pressure vessel and the operating machinery. The maintenance requirements for it must not only consider the accidental opening and closing of the valve, but also take into account that the valve is in a pressureless state for most of the time.
Valves that remain in place for a long period of time may experience some degree of operability, which is due to ageing of the packing, corrosion of the surface of the moving parts, or a harmful build-up. In some applications, it is finally necessary to formulate a cyclical partial or total cycle plan for such valves.
The integrity of the pressure boundary is mainly the requirement that the pressure-receiving parts be intact, the pressure-resistant seals at the fixed-assembly joints, and the effective working seal between the valve stem and the valve cover that guarantees movement in most cases. The pressure boundary and fixed assembly connection should be checked and confirmed to be good. Ventilation butterfly valve stem seal leakage is usually caused by packing wear and can be compensated by tightening packing glands. Excessive pressure may increase the friction of the stem, making the stem difficult to operate and accelerating the wear of the packing. Valves with better internal seals affect their sealing performance due to damage or normal wear. Due to the poor working conditions, the estimation and repair of seal effectiveness is beyond the scope of this manual, because various structural forms vary greatly. If it is necessary to know in advance that it is necessary to cooperate with the manufacturer to find a suitable method.
The external structure of the valve is generally easy to check and maintain. Reasonable measures should be taken to prevent mechanical damage to the valve and to prevent erosion of the valve by deposits, chemicals, or moist gases in the atmosphere, thereby deteriorating its quality. Working interfaces such as threads, bearings or gears should be regularly lubricated.
Nine, possible failures, causes and maintenance methods
Possible failures Causes of failure Elimination Method Packing Leakage Packing gland Uncompressed packing Less than sufficient number of packing Failure due to excessive use or improper storage Tighten the nuts evenly.
2. Increase the number of packing rings.
3. Replace the new packing (the joints of each ring should be staggered).
Leakage between seals 4. The sealing surface has dirt attached or the sealing ring is damaged. 4. Remove dirt or rework trim or replace seals.
The drive is inflexible or the closure cannot be opened or closed. Packing pressure too tight.
6. Packing glands are skewed.
7. The drive mechanism or connectors are damaged.
8. Stem bent. 5. Loosen the nut on the packing gland properly.
6. Correct the packing gland.
7. Disconnect the repair drive mechanism or connector.
8. Correct the stem.
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