Application scope and technical requirements of power station valves for repairing gear damage in valve Transmission Devices (I)

Application scope and technical requirements of power station valves for repairing gear damage in valve Transmission Devices (I)

Adhesive insert teeth method. First need to remove broken tooth, and processed into dovetail groove on the tooth root, using the same material processing new tooth piece into dovetailed, cooperate with the dovetail groove of the gear on, keep the 0.1 ~ 0.2 mm clearance, and make new machining tooth, have certain allowance for finish, after being firm bonding of new teeth and slots, make template of gear teeth, and then finishing new teeth, Until the sample is in uniform contact with the teeth. This method is suitable for gear with poor welding performance.
Figure 7-9 shows how to repair the damaged teeth of a gear.
Figure 7-9 shows how to repair the damaged teeth of a gear
1. Repair method of individual tooth damage of gear
(1) Adhesive insert tooth method. First need to remove broken tooth, and processed into dovetail groove on the tooth root, using the same material processing new tooth piece into dovetailed, cooperate with the dovetail groove of the gear on, keep the 0.1 ~ 0.2 mm clearance, and make new machining tooth, have certain allowance for finish, after being firm bonding of new teeth and slots, make template of gear teeth, and then finishing new teeth, Until the sample is in uniform contact with the teeth. This method is suitable for gear with poor welding performance.
(2) Welding insert tooth method. This method is suitable for gear with good welding performance, and its repair process is the same as the method of bonding insert teeth.
(3) Embedded pile surfacing method. In the broken tooth drilling tapping, embedded on one or more bolt piles, with the surfacing method in the broken tooth surfacing new tooth, ***, processed into the same tooth tooth as the original tooth.
2. Gear fracture repair
In the valve transmission device, if the gear breaks, it should be replaced with a new spare part. If there is no new spare part temporarily, it can be repaired according to the method shown in Figure 7-10.
Gear fracture repair (1) The fracture of the broken gear is processed into a groove, and then the broken gear is inserted into the gear for recovery, and spot welding fixed.
(2) the clamping groove of the strengthening plate is made on the two end faces of the gear edge. The outer diameter of the groove should be 5mm smaller than the diameter of the root circle, and the inner diameter is slightly smaller than the inner diameter of the rim. The depth of the groove depends on the thickness of the gear, generally between 3 and 6mm.
(3) The size of the clamping groove shall prevail, and the car shall make two strengthening rings. The two strengthening rings shall be riveted and fixed in the clamping groove of the two end faces.
Application scope and technical requirements of power station valves (1) This standard specifies the pressure and temperature grade of power station valves and the general requirements of materials, design, inspection, marking, packaging, storage, transportation, delivery documents, etc., and gives a guide for ordering requirements. Valve materials should be selected according to the use conditions and manufacturing requirements; Bolts, nuts and other fastener materials should be selected according to the use of pressure and temperature. When selecting materials for bearing parts of the shell, the maximum operating temperature shall be specified in Appendix C. This standard presents low or minimum requirements for valve design, but is not the complete design requirement.
1 scope
This standard specifies the pressure and temperature grade of power station valves and the general requirements of materials, design, inspection, marking, packaging, storage, transportation, delivery documents, etc., and gives a guide for ordering requirements.
This standard applies to all types of valves used in power station soda water system under the following parameters:
– Nominal pressure is not more than 42MPa, maximum operating temperature is not more than 450℃;
– Working pressure is not more than 26MPa, maximum working temperature is not more than 540℃;
– Working pressure is not more than 6MPa, maximum working temperature is not more than 570℃
2 Normative reference documents
The provisions of the following documents are incorporated into this international standard by reference. All subsequent amendments (excluding errata) or revisions to dated references do not apply to this international Standard. However, parties to an agreement under this International Standard are encouraged to investigate the availability of *** versions of these documents. *** versions of undated references apply to this international Standard.
Radiography and quality classification for fusion welded butt joints of steel
GB/T 3985 Asbestos rubber sheet
GB/T 4213-1992 Pneumatic control valve
GB/T 4622.1~3 Wound gasket
Steel castings — Classification of radiographs and film grades
Casting dimensional tolerance and machining allowance (eqvISO 8062:1994)
GB/T 9112-1988 Steel pipe methods, general types and parameters
Monolithic steel pipe flanges
Butt welded steel pipe flanges
GB/T 9433-1988 Grade method for penetration detection and defect display marks of steel castings
GB/T 9444-1988 Method of magnetic particle inspection and quality rating for steel castings
Technical specifications of temperature and pressure reducing valves for power stations
Specification for power station control valves
Metal valves for flanged connection — Length of construction (NEQ ISO 5752:1982)
Connections for multi-turn valve drives
Connections for partial rotary valve drives
Steel valves — General requirements (NEQ ANSI B16.34:1981)
Specification for copper alloy castings for general purpose valves
Specification for austenitic steel castings for general purpose valves
General purpose flanged and butt-welded steel gate valves
Universal valves for flanged steel globe valves and lift check valves
General purpose valves — Steel swing check valves
Valves for general purpose with flanged and butt-welded steel ball valves
General requirements for safety valves (EQV ISO 4126:1984)
Safety valve Performance Test Method (NEQ ANSI/ASTM PTC 25.3:1976)
Spring-loaded safety valves (NEQ JIS B8210:1978)
Pressure reducing valves — General requirements
Pressure reducing valves — Performance test method
Pilot type pressure reducing valves
Structural length of valves
Technical requirements for pipe flanges (NEQ DIN 2535~2547, DIN 2573~2637)
JB/T106 valve logo and identification paint
JB/T 1613-1993 Boiler pressure elements welding specification
JB/T 2203-1999 Spring safety valve construction length
JB/T 2205-2000 Pressure reducing valve construction length
JB/T 4018 power station valve model formulation method
JB/T 5263-1991 Technical specification for steel castings for power station valves (NEQ ANSF/ASTM A 217M)
JB/T 6900-1993 drain valve
JB/T 7370 flexible graphite braided packing
JB/T 7927-1999 Appearance quality requirements for steel castings of valves
JB/T 8219-1999 Electric actuators for industrial process measurement and control systems
Specification for electric devices for common valves
Specification for electric devices for flameproof valves
JB/T 9624-1999 Specification for safety valve of power station
JB/T 9625-1999 Technical specification for pressure steel castings for boiler piping accessories
JB/T 9626-1999 Specification for boiler forgings
JC/T 67 rubber asbestos packing
JC/T 68 oil impregnated asbestos packing
Sdgj6-1990 Technical provisions for stress calculation of steam water pipelines in thermal power plants
3 Terms and definitions
The following terms and definitions apply to this international Standard.
Pressure-temperature rating
A relatively high permissible operating pressure of the selected material as indicated by gauge pressure at a specified operating temperature.
4 Order Requirements
In order to facilitate the buyer’s ordering, table A.1 in Appendix A provides the basic ordering requirements guide for reference, and Table A.2 provides further special ordering requirements guide for different types of valves.
Pressure – temperature class
Pressure – temperature classes for various materials are specified in Appendix B.
6 Technical Requirements
6.1 general requirements
6.1.1 The design of valves shall meet the requirements of safety and reliability.
6.1.2 In addition to meeting the requirements of this standard, power station valves shall also meet the requirements of the following standards:
A) Steel valves shall conform to the requirements of GB/T 12224-1989;
B) Gate valves shall comply with the provisions of GB/T 12234-1989;
C) Globe valves and check valves shall comply with the provisions of GB/T 12235-1989 and GB/T 12236-1989;
D) Ball valves shall comply with the provisions of GB/T 12237-1989;
E) Safety valves shall conform to the requirements of GB/T 12241-1989, GB/T 12242-1989, GB/T 12243-1989 and JB/T 9624-1999;
F) Pressure reducing valves shall conform to the requirements of GB/T 12244-1989, GB/F 12245-1989 or GB/T 12246-1989;
G) The temperature and pressure reducing valve shall conform to the provisions of GB/T 10868-1989;
H) The regulating valve shall conform to the provisions of GB/T 10869-1989;
I) Blowdown valves shall comply with JB/T 6900-1993;
J) Valve electric device shall conform to JB/ T8528-1997AK JB/T8529-1997;
K) The valve electric actuator shall conform to the provisions of JB/T 8219-1999;
L) Valve pneumatic actuators shall comply with the provisions of GB/T 4213-1992.
6.1.3 When a new technology (such as new structure, new material, new process, etc.) is adopted and the technical requirements of this standard are not covered, it shall be adopted after necessary test or qualified appraisal and approved by the buyer.
6.2 material
6.2.1 Valve materials shall be selected according to the use conditions and manufacturing requirements; Bolts, nuts and other fastener materials should be selected according to the use of pressure and temperature. When selecting materials for bearing parts of the shell, the maximum operating temperature shall be specified in Appendix C. Please refer to Appendix D for surfacing material and hardness selection guide
6.2.2 The materials and welding materials used for the bearing parts of the valve shall comply with relevant national standards, industrial standards or the material standards stipulated in the order contract. The material manufacturing unit must guarantee the quality of the materials and provide quality certificates. Metal materials and weld metal chips should have specified strength, toughness, secondary length and good fatigue resistance and corrosion resistance under service conditions.
6.2.3 Steel castings shall comply with JB/T 9625-1999 or JB/T 5263-1991.
6.2.4 Forgings shall conform to JB/T 9626-1999.
6.2.5 Austenitic steel castings shall conform to the provisions of GB/T 12230-1989.
6.2.6 Copper alloy castings shall comply with the provisions of GB/T 12225-1989.