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 diameter of the wing ring (D5). Moreover, the casing must be poured at the inner wall at one time. Germany tested to obtain valves from these plants in World War II because the valve supply was blocked, but later changed to produce artificial valves.
At first, valve trees were good at growing in South America, but now there are many valve trees planted in Southeast Asia through artificial transplantation.
In fact, Asia has become the origin of important valves. The valve made of inulin can cut sensitivity. Although more than half of the other valve materials are artificial, natural valves are still very important in some fields, such as automobile and other industries. Pneumatic ball valve can also be called flexible pneumatic ball valve, pneumatic ball valve, pneumatic ball valve, flexible pneumatic ball valve, valve expansion joint, pneumatic ball valve, shock absorber, etc. It is a pipe connector with high elasticity, high air tightness, medium resistance and weather resistance.
The pneumatic ball valve is generally composed of inner rubber layer, fabric reinforcement layer (reinforcement layer has multi-layer rubber scraped nylon cord fabric), middle rubber layer, outer rubber layer, end reinforced 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 the valve, such as high elasticity, high air permeability, medium resistance, weather resistance and radiation resistance, which can reduce the vibration and noise of the pipeline and compensate for the expansion and contraction caused by temperature changes. The valve materials used vary according to the media, including natural rubber, styrene butadiene rubber, butyl rubber, butyl rubber, EPDM, neoprene rubber, silicon valve, fluorine valve, etc.
It has the functions of heat resistance, acid resistance, alkali resistance, corrosion resistance, abrasion resistance, oil resistance, etc. Valve fabric pneumatic valves are mainly fiber fabrics, valves, and other high-temperature resistant materials. It can compensate the vibration of fan and air duct operation and pipeline deformation. The fiber fabric expansion joint can compensate axial, transverse, angular and other products. It has the characteristics of no thrust, simplified support design, corrosion resistance, high temperature resistance, noise elimination and vibration reduction, and is especially suitable for hot air pipes and soot pipes in power plants. Fiber fabrics and insulation cotton in non-metallic pneumatic valves have sound absorption and vibration isolation functions, which can effectively reduce the noise and vibration of boiler, fan and other systems. Simple structure, light weight and convenient maintenance. Technical standards: products shall be marked in the following order: product code, type code, structure code, performance code, working pressure, nominal diameter. The product and structure codes are specified as follows: flexible pneumatic ball valve RFJ, single ball valve D, double ball valve S, elbow W, concentric reducer Yt, eccentric reducer Yp, fan coil connector F. Mark example: RFJD-1.6 × 200,. It refers to a single spherical flexible pneumatic ball valve with a nominal diameter of 200mm, and the working pressure is 1.6Mpa. Working pressure: the test pressure of the pneumatic ball valve is 5 times of the working pressure, and the pressure is 3 times of the working pressure.