Technical conditions of high temperature and high pressure stop valve for power station
The People’s Republic of China Electric Power Industry Standard DL/T 531—94 Power Station High Temperature and High Pressure Globe Valve Gate Valve Technical Conditions
Technical Specification of High Temperature High Pressure Globe Stop Valves and Gate Valves for Power Station
中华人民共和国电力工业部1994-03-18 批准1994-10-01 实施
1 Subject content and scope of application
本标准规定了电站用高温、高压截止阀、闸阀的分类及产品的质量要求。本标准适用于公称压力pN 为20、25、32MPa，工作温度等于或低于425℃；工作压力p为10、14、17MPa，工作温度为510、540、570℃；工作介质为水、蒸汽的截止阀、闸阀。
2 Reference standards
JB 2765 Valve Terminology
JB 4018 Power Station Valve Model Compilation Method
Technical requirements for ZBJ 98015 pressure-bearing steel castings
GB 12231 Appearance quality requirements of valve steel castings
JB 2633 Technical requirements for boiler forgings
GB 1176 Technical conditions for casting copper alloys
GB 699 Technical requirements for high-quality carbon structural steel
GB 3077 Technical conditions for alloy structural steel
GB 979 Classification and Technical Conditions of Carbon Steel Castings
GB 4981 Pressure test of industrial valves
GB 6414 Casting Dimension Tolerance
GB 1804 Tolerance and the limit deviation of the size of the fit without tolerance
GB 3595 Technical requirements for power station valve manufacturing
GB 5677 Radiographs and film classification methods for steel castings
GB 7233 Ultrasonic flaw detection and quality rating method for steel castings
GB 9443 Steel castings penetrating flaw detection and quality rating method
GB 9444 Magnetic particle inspection and quality rating method for steel castings
SDB DZ series valve electric device
SDZ packaging general technical conditions
3 term
Globe valve-a valve whose opening and closing parts (disc) are driven by the valve stem to move up and down along the axis of the valve seat (sealing surface);
Gate valve-a valve whose opening and closing parts (gate) are driven by the valve stem to move up and down along the sealing surface of the valve seat;
Manual cut-off valve, gate valve-cut-off valve, gate valve driven by handwheel, impact handwheel or gear rotation;
Electric cut-off valve, gate valve-cut-off valve, gate valve driven by an electric device.
5.7.1 The depth of the stuffing box is twice the diameter of the stem. When the stem diameter is 2mm and above, the deepest depth is 64mm.
5.7.2 For valves with internal pressure self-sealing structure, the packing shall be flexible graphite metal spiral wound gasket without joint packing.
5.8 Handwheel
The handwheel used to operate the valve is closed in a clockwise direction, but there must be a mark on the handwheel.
5.9 Electric device
The electric device of the electric valve should meet the requirements of "DZ Series Valve Electric Device".
5.10 Basic assembly requirements
5.10.1 All assembled parts and components (including purchased parts and outsourcing parts) must have inspection certificates and marks.
5.10.2 The main matching dimensions and roughness of parts should be re-inspected and optimized.
5.10.3 The assembly surface and friction surface of the parts shall not have scratches that affect the performance.
5.10.4 All assembled parts and components (including purchased parts and outsourcing parts) shall not have burrs, rust and scratches on the machined surface, and they shall be qualified by visual inspection
The assembly can only be carried out after passing the spectral inspection.
5.10.5 After assembly, the fasteners should be tightened and not loosened.When assembling the fasteners, the screws should be coated with heat-resistant threaded grease.
5.10.6 For manual valves, there must be no jamming during the lifting and lowering process of the valve stem, and the hand feel is even.
5.10.7 After the electric valve is assembled, the travel switch of the electric device should be adjusted to the state of synchronization with the fully open and closed positions of the valve.The closing of the shut-off valve is based on the action of the torque protection device.Electricity is changed to manual operation, and the hand feels even when the handwheel rotates.
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 the single gate is 2/3 of the width of the seat sealing surface; the double gate is 1 of the width of the seat sealing surface. /2.
5.11 Derusting and painting
5.11.1 Rust removal and painting should be carried out after the water pressure test is qualified, and the water stains in the cavity should be removed.
5.11.2 The processed surface of the valve is coated with anti-corrosion grease, and the non-processed outer surface is painted.
5.11.3 Before painting, the non-processed surface must be cleaned up, and then a layer of red lead primer, followed by a layer of paint.
6 Test method
6.1 Material test
The test of the materials used for the valve shall comply with the requirements in 5.2.2.
6.2 Hydraulic test
The entire hydraulic pressure test of the valve shall be carried out in accordance with the provisions in Article 8.4 for the shell strength test and the sealing and inverted sealing tests.
6.3 Type test
6.3.1 Type test must be carried out in one of the following situations:
a. Trial production of new products;
b. Old products when the structure, materials, and craftsmanship have undergone major changes;
c. The higher-level quality supervision agency puts forward the requirements for type testing.
6.3.2 The type test includes the following:
a. The test content included in Chapter 6.1 and Article 6.2 and XNUMX of this standard;
b. Metallographic analysis must be done when new materials or material components and processes have major changes;
c. Do stress analysis test during shell hydraulic test;
d. Static pressure life test;
e. Resistance characteristic test.
g. Whether the position of the label and its parameters are correct according to the provisions of 9.1.1; whether the valve body marking is correct according to the provisions of Article 9.1.2;
h. The factory valve is not required to be disassembled and inspected before installation. The manufacturer is responsible for repair or replacement due to product quality problems within half a year after installation.
After passing the inspection and checking that the inspection materials are correct and complete, prepare the factory number, and the quality inspection department will issue a product certificate, which will be handed over to the user along with the product.
9 Marking, packaging, transportation and storage
9.1 Logo
9.1.1 The sign shall have the following items:
a. The name of the manufacturer;
b. Product name and model;
c. The main parameters of the product: nominal pressure, working pressure, limit temperature, type of working medium, maximum torque;
d. Manufacturing date and production batch number;
e. Quality level mark.
9.1.2 The valve body must be cast with the following:
a. Material code;
b. Nominal pressure (or working pressure at working temperature);
c. Nominal diameter;
d. Medium flow direction;
e. Valve body furnace number.
9.2 Packaging, transportation and storage
9.2.1 During packaging, transportation and storage, the valve should be closed.After anti-rust treatment and painting, the channels at both ends are closed with cover plates to prevent the intrusion of dirt and sewage.
9.2.2 When the product is packed in the box, it should be fixed in the box, and it is not allowed to make the handwheel or electric device support the weight of the valve itself.
To ensure that it will not be damaged during transportation.
9.2.3 Each valve should be accompanied by the following technical documents when leaving the factory, and sealed in a moisture-proof and waterproof bag:
a. Product quality certificate;
b. Physical and chemical inspection report of main parts;
c. Product manual (general assembly drawing, drawing of vulnerable parts);
d. Packing list.
9.2.4 The product should be stored in a dry place, and it is not allowed to store or stack the product in the open air.