Summary of bidirectional hard-sealed butterfly valves:
Two-way hard-sealed butterfly valves can be installed at temperatures less than 425 C. The medium is gas, air, steam, water, sea water, oil and other industrial pipelines for regulating flow and cutting off media. The driving modes include manual, worm wheel drive, pneumatic, hydraulic, electric, electro-hydraulic linkage and other actuators, which can realize long-distance control and automatic operation. Metal hard seal butterfly valve series products, long life, energy-saving butterfly valve. Its structure is designed by three-dimensional braiding principle, and the valve seat adopts a multi-level structure compatible with hard and soft seals. It has exquisite processing and advanced technology. This product consists of valve body, butterfly plate, multi-level seat, valve stem, transmission mechanism and other main components. Therefore, it is widely used in pipelines with corrosive media such as metallurgy, power, petroleum, chemical industry, air, gas, combustible gas and water supply and drainage.
Because the butterfly valve of this product is designed by three-dimensional eccentricity principle, the space movement track of the sealing surface is idealized, and the sealing surfaces are free of friction, interference and proper selection of sealing materials, so that the sealing, corrosion resistance, high temperature resistance and wear resistance of the butterfly valve are guaranteed reliably. Its main characteristics are as follows:
1. The opening and closing speed of butterfly valve (DN 600) is controlled below 390, the service life of butterfly valve is long, and the switch can be more than 40000 times (more than 10 years).
2. Three-dimensional braiding structure makes the butterfly plate tighter and tighter. Its sealing performance is reliable and leak-free.
3. High pressure resistance, corrosion resistance, wear resistance, long service life, etc.
4. Surfacing cobalt-based cemented carbide is used on the sealing surface of disc plate. The sealing surface is wear-resistant and has long service life.
5. Large size butterfly plate should be double flat truss flow structure with high strength, large overflow area and small flow resistance.
6. The valve has two-way sealing function. It can be installed in any direction without restriction of medium flow direction or influence of space position.
7. In order to reduce the water resistance, the butterfly valve shaft should adopt two-stage structure, and the bearing of the valve shaft should adopt self-lubricating bearing, so the friction resistance in operation is small.
8. The connection between the butterfly plate and the valve shaft is designed with the pull-out pin structure. The pull-out pin does not pass through the center of the valve shaft, and will not weaken the strength of the shaft, and the joint surface with the valve shaft is greatly increased. By tightening the pull-out pin nut, the pre-tightening force between the pull-out pin and the joint surface of the valve shaft is generated, so that the butterfly plate valve shaft is tightly combined without clearance and is opened. When the valve is closed, no impact load will be generated, which makes the butterfly plate rotate smoothly and seal reliably.
9. The opening and closing force and the opening and closing moment of the butterfly valve are changed during the opening and closing process. The opening and closing moment of the butterfly valve under the working pressure should be controlled at about 230N * m, and the operating force applied on the handwheel should be about 20 kg. When the butterfly valve is closed and opened, the operating force applied to the handwheel shall not exceed 40 kg. The maximum value is to design and manufacture butterfly valves at the final moment of closure or the initial moment of opening in order to reduce the closing force and closing moment.
10. For DN > 300 butterfly valve, it should have butterfly plate axial adjustment and fixing device. Through precise adjustment and fixing of the butterfly plate's axial position, the position of the butterfly plate on the valve seat is in the best sealing state. For the sag of butterfly plate which may be caused during long-term use, it is also convenient to further adjust locking to achieve zero leakage in long-term use.
Adopt the standard:
Design and manufacture conform to GB/T12238-1989 standard of general valve flange and butterfly valve with clamp connection.
The structure length of metal valve meets GB/T 12221-2005 standard.
General valve flange and butterfly valve with clamp connection conform to GB/T 17241.6-2008 standard.
The technical conditions of ductile iron castings for general purpose valves meet the GB/T 12227-2005 standard.
The marking and painting of the valve conform to JB/T 106-2004 standard.
General valve marking conforms to GB12220-89;
The static pressure life test procedure of Butterfly Valve conforms to JB/T8863-2004 standard.
General valve test conforms to GB13927-92 standard.
Standard GB/T 17219-200 for safety evaluation of drinking water conveyance and distribution equipment and protective materials;
Stainless steel bars meet the requirements of GB/T 1220.
The packaging and storage of the valves shall conform to the standard JB/T7928.
Rubber Sealing Ring - Joint Sealing Ring for Water Supply and Drainage Pipeline: HG/T3091-2000;
The inner and outer surfaces of the valve body, butterfly plate and operating mechanism should be sandblasted to remove rust, moisture and oil impurities.
The inner and outer parts of butterfly valve shall be coated with non-toxic epoxy resin powder to prevent rusting and fluid corrosion, and the color shall be Turkish blue. Coatings should be smooth, uniform and defect-free. Coatings do not dissolve in water after drying, and do not affect water quality.