People's Republic of China Power Industry Standard DL / T 531-94 power station high temperature and high pressure stop valve gate valve Technical Specification of High Temperature High Pressure Globe Stop Valves and Gate Valves for Power Station People's Republic of China Ministry of Electric Power 1994-03-18 approved 1994 - 10-01 Implementation 1 Subject Matter and Scope This standard specifies the classification of high temperature and high pressure stop valves and gate valves for power plants and product quality requirements. This standard applies to the nominal pressure pN is 20,25,32 MPa, the working temperature is equal to or lower than 425 ℃; working pressure p is 10,14,17 MPa, the working temperature is 510,540,570 ℃; working medium is water, steam Shut-off valve, gate valve. 2 reference standard JB 2765 valve terminology JB 4018 power station valve preparation method ZBJ 98015 pressure-bearing steel casting technical conditions GB 12231 valve castings appearance quality requirements JB 2633 boiler forgings GB 1176 casting copper alloy technical conditions GB 699 high-quality carbon Technical conditions of structural steel GB 3077 alloy structural steel technical conditions Classification and technical conditions of GB 979 carbon steel castings GB 4981 pressure test of industrial valves GB 6414 casting dimensional tolerances GB 1804 tolerances and tolerances with tolerance limits of non-dimensional deviation GB 3595 power station Valve manufacturing technology GB 5677 casting radiographs and film classification methods GB 7233 steel castings ultrasonic flaw detection and quality rating method GB 9443 steel castings penetrant detection and quality rating method GB 9444 castings magnetic particle inspection and quality rating method SDB DZ Series valve electric device SDZ packaging general technical conditions 3 Terms Shut-off valve - Opening and closing pieces (valve flap) by the stem along the valve seat (sealing surface) axis for lifting movements of the valve; gate valve - opening and closing (Gate) by the valve stem to move along the sealing surface of the valve lift movements of the valve; Manual shut-off valve, gate valve - by handwheel, impact handwheel or gear rotary drive stop valve, gate valve; Electric stop valve, gate valve - Shut-off valve driven by electric device, gate valve. 5.7.1 The depth of stuffing box is 2 times of the stem diameter. When the stem diameter is 64mm and above, the deepest depth is 110mm. 5.7.2 Pressure self-sealing valve structure, the filler should be flexible graphite spiral wound gasket without joint filler. 5.8 Handwheel The handwheel used to operate the valve is to be turned clockwise, but the handwheel must be marked. 5.9 Electric device Electric valve configured electric device should be consistent with "DZ series valve electric device" requirement. 5.10 Assembly basic requirements 5.10.1 Where the assembly of zero, parts (including purchased parts, outsourcing) must hold proof of inspection and logo. 5.10.2 The main parts with the size and roughness should be re-examination, and optimize the combination. 5.10.3 parts of the assembly surface and the friction surface shall not affect the performance of the abrasion. 5.10.4 Where the assembly of zero, parts (including purchased parts, outer parts) shall not have burrs, corrosion and machining surface bumps, visual inspection after passing the spectral examination before assembly. 5.10.5 Fasteners should be fastened after assembly, not loose. Fastener assembly, the screws should be coated with heat-resistant Sikou fat. 5.10.6 manual valve, stem lift process may not have jam ashamed, feel evenly. 5.10.7 After the electric valve is equipped, the electric device should be adjusted to the travel switch with the valve fully open, closed position synchronization. Shut-off valve to torque protection device action based. Electric change manual, hand wheel rotation should be uniform. 5.10.8 After assembly, when the gate valve is closed, the center of the gate should be higher than the center of the valve seat, the value of single gate is 2/3 of the valve seat sealing surface width; the double gate is the valve seat sealing surface width of 1 /2. 5.11 rust, paint 5.11.1 derusting, painting should be carried out after the water pressure test, and the cavity of the water stains removed. 5.11.2 valve surface coating anti-grease, non-processing the outer surface of paint. 5.11.3 Before painting, it is necessary to clean the non-processed surface, apply a layer of red lead primer, and then apply a layer of paint. 6 Test Methods 6.1 Materials Test Valve material testing shall comply with the provisions of Article 5.2.2. 6.2 Water pressure test The entire hydraulic pressure test according to the provisions of Article 8.4, the shell strength test and seal, inverted seal test. 6.3 type test 6.3.1 is one of the following circumstances, the need for type testing: a trial of new products; b old products when the structure, materials, processes have major changes; c higher quality supervision agencies proposed type test Request. 6.3.2 Type test includes the following: a. The contents of the test included in Chapter V of this standard and 6.1 and 6.2; b. The new material or material composition, the process has major changes, you must do metallographic analysis; c Shell hydrostatic test, stress analysis test; d. Static pressure life test; e. Resistance characteristics test. g. The location of the signs and their parameters according to the provisions of 9.1.1 are correct; Body signs according to the provisions of Article 9.1.2 is correct; h. Factory valves, users do not disassembly inspection before installation, within six months after installation due to product quality There is a problem, by the manufacturer responsible for repair or replacement. After the inspection of qualified products, and check the inspection information is correct, the preparation of the factory number, quality inspection department issued a product certification, the certificate with the product to the user. 9 signs, packaging, transportation and storage 9.1 signs 9.1.1 signs should have the following: a manufacturer name; b product name and model; c main product parameters: nominal pressure, working pressure, temperature limit, the working medium Type, maximum torque; d. Manufacturing date and production lot number; e. Quality grade mark. 9.1.2 Valve body must be cast the following: a. Material code; b. Nominal pressure (or working pressure at the working temperature); c. Nominal diameter; d. Medium flow direction; 9.2 Packaging, Transport and Storage 9.2.1 The valve shall be closed during packaging, transport and storage. After the anti-rust treatment and painting, both ends of the channel to the cover closed to prevent dust, sewage intrusion. 9.2.2 When the product is packed in the factory, it should be fixed in the box, and the weight of the valve itself should not be supported by the hand wheel or the electric device to ensure that the product will not be damaged during transportation. 9.2.3 Each valve should be shipped with the following technical documents, and sealed in a moisture-proof, waterproof bag: a. Product Quality Certificate; b. The main parts of the physical and chemical test reports; c. Total assembly drawing, fragile parts map); d packing list. 9.2.4 The product should be stored in a dry place, do not allow open storage or product stacking.
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