Classification according to the medium used: general (ordinary) electric butterfly valve, high-temperature electric butterfly valve, acid and alkali resistant electric butterfly valve, wear-resistant electric butterfly valve, desulfurization special electric butterfly valve, etc. Classification according to working pressure: 0.25Mpa, 0.6Mpa, 1.0Mpa, 1.6Mpa, 2.5Mpa, 4.0Mpa.
Sealing requirements: 1. When the upstream surface is a corrosive medium, the gap can be sealed with sealing materials. See the waterproof casing atlas for the practice; Installation drawing of flexible waterproof sleeve (Type A). 2. Filler materials of flexible waterproof casing: asphalt hemp fiber, polystyrene board, PVC foam plastic board. 3. Sealing paste: polysulfide sealing paste, polyurethane sealing paste.
4. The dimensional tolerance and geometric tolerance of welding structure shall comply with JB/T5000.3-1998. Manual arc welding is adopted for welding, and the welding rod model is E4303, and the brand is J422. The basic shape and size of weld groove shall comply with GB985-88.
5. When flexible waterproof casing is rolled, the allowable deviation of perimeter is D2 ≤ 600, D2>600 ± 0.0035D2.
6. The thickness of the concrete wall where the wall passes through shall not be less than 300, otherwise the wall shall be thickened on one side or both sides, and the diameter of the thickened part shall be at least D5+200.
7. The weight of flexible waterproof casing shall be calculated with L=300. If the wall thickness is greater than 300, it shall be calculated separately.
8. If a non concrete wall is encountered at the place where the flexible waterproof casing penetrates the wall, the concrete wall shall be used locally, and the pouring range shall be 200 larger than the wing ring diameter (D5). Moreover, the casing must be poured at one time on the inner wall, and the screw thread connection electric butterfly valve is generally designed for connecting pipes with smaller diameter, which is convenient. Like other electric butterfly valves, different rubber materials are selected for different media, including natural rubber, styrene butadiene environment, nitrile butadiene, butyl, etc., which have excellent performance in heat resistance, acid resistance, corrosion resistance, etc. There are many other advantages of screw connection electric butterfly valve. The utility model has the advantages of convenient installation, easy replacement, high pressure resistance, light weight, etc.
Electric butterfly valve can also be called flexible electric butterfly valve, rubber soft connection, soft joint, flexible electric butterfly valve, rubber expansion joint, electric butterfly valve, shock absorber, etc. It is a pipe connector with high elasticity, high air tightness, medium resistance and weather resistance. The electric butterfly valve is generally composed of inner rubber layer, fabric reinforcement layer (reinforcement layer includes multi-layer rubber scraped nylon cord fabric), middle rubber layer, outer rubber layer, end reinforcement metal ring or steel wire ring, which is formed by high temperature and high pressure vulcanization and loosely combined with metal flange or parallel joint. This product makes use of the advantages of rubber such as high elasticity, high air permeability, medium resistance, weather resistance and radiation resistance, which can reduce the vibration and noise of pipes and compensate for the expansion and contraction caused by temperature changes. The rubber materials used vary according to the media, including natural rubber, styrene butadiene rubber, butyl rubber, butyl rubber, EPDM, chloroprene rubber, silicone rubber, fluororubber, etc.