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GB 25974.3-2010 PDF English

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GB 25974.3-2010: [GB/T 25974.3-2010] Powered support for coal mine -- Part 3: The hydraulic control system and valves
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GB 25974.3-2010: [GB/T 25974.3-2010] Powered support for coal mine -- Part 3: The hydraulic control system and valves


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NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 73.100 D 97 Powered support for coal mine - Part 3: The hydraulic control system and valves ISSUED ON: JANUARY 10, 2011 IMPLEMENTED ON: JUNE 01, 2011 Issued by: General Administration of Quality Supervision, Inspection and Quarantine of PRC; Standardization Administration of PRC.

Table of Contents

Foreword ... 3 Introduction ... 4 1 Scope ... 5 2 Normative references ... 5 3 Terms and definitions... 7 4 Categories ... 10 4.1 Product categories ... 10 4.2 Product model ... 10 5 Requirements ... 13 5.1 General requirements ... 13 5.2 Requirements for hydraulic control system ... 13 5.3 Valve requirements ... 15 6 Test methods ... 21 6.1 Test conditions ... 21 6.2 Test method for hydraulic control system ... 22 6.3 Part manufacturing quality ... 23 6.4 Test method for yield valve ... 23 6.5 Test method for pilot check valve ... 27 6.6 Test method for directional valve ... 31 6.7 Test method for shut-off valve ... 36 6.8 Test methods for other valves ... 38 7 Inspection rules ... 38 7.1 Inspection classification ... 38 7.2 Inspection items ... 39 7.3 Group-batching rules and sampling scheme ... 40 7.4 Sampling method ... 44 7.5 Judgment rules ... 45 8 Marking, packaging, storage ... 45 Appendix A (Normative) Technical requirements for coating of valve parts ... 46 Powered support for coal mine - Part 3: The hydraulic control system and valves

1 Scope

This Part of GB 25974 specifies the terms and definitions, classification, requirements, test methods, inspection rules, marking, packaging and storage of hydraulic control systems and valves for powered supports for coal mines (hereinafter referred to as supports). This Part is applicable to the hydraulic control systems and valves of various coal mine supports and other equipment with supporting functions, including various hydraulic control systems, yield valves, pilot check valves, directional valves, shut-off valves, etc. This Part does not apply to the valves inside the superchargers, columns, jacks (such as column bottom valves).

2 Normative references

The provisions in following documents become the provisions of this Part through reference in this Part of GB 25974. For the dated references, the subsequent amendments (excluding corrections) or revisions do not apply to this Part; however, parties who reach an agreement based on this Part are encouraged to study if the latest versions of these documents are applicable. For undated references, the latest edition of the referenced document applies. GB/T 197-2003 General purpose metric screw threads - Tolerances (ISO 965-1:1998, MOD) GB/T 321-2005 Preferred numbers - Series of preferred numbers (ISO 3:1973, IDT) GB/T 699 Quality carbon structural steels GB/T 1184-1996 Geometrical tolerancing - Geometrical tolerance for features without individual tolerance indications (eqv ISO 2768-2:1989) GB/T 1220 Stainless steel bars GB/T 1239.1 Cold coiled helical springs technical specifications - Part 1: Extension spring GB/T 1239.2 Cold coiled helical springs technical specifications - Part 2: Compressions spring GB/T 1239.3 Cold coiled helical springs technical specifications - Part 3: Torsion spring GB/T 1239.4 Cold coiled helical springs technical specifications - Part 3: Torsion spring GB/T 1800.1-2009 Geometrical product specifications (GPS) - Limits and fits - Part 1: Bases of tolerances deviations and fits (ISO 286-1:1988, MOD) GB/T 1804-2000 General tolerances - Tolerances for linear and angular dimensions without individual tolerance indications (eqv ISO 2768-1:1989) GB/T 2828.1-2003 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection (ISO 2859-1:1999, IDT) GB/T 2829-2002 Sampling procedures and tables for periodic inspection by attributes (Apply to inspection of process stability) GB/T 3452.1 Fluid power systems - O-rings - Part 1: Inside diameters, cross- sections, tolerances and size identification code (GB/T 3452.1-2005, ISO 3601- 1:2002, MOD) GB/T 3452.2 Fluid power systems - O-rings - Part 2: Quality acceptance criteria (GB/T 3452.2-2007, ISO 3601-3: 2005, IDT) GB/T 3452.3 Housing dimensions for O-ring elastomer seals in hydraulic and pneumatic applications GB/T 9439 Grey iron castings GB/T 9799 Metallic coatings - Electroplated coatings of zinc on iron or steel (GB/T 9799-1997, eqv ISO 2081:1986) GB/T 11352 Carbon steel castings for general engineering purpose (GB/T 11352- 2009, ISO 3755:1991; ISO 4990:2003, MOD) GB/T 13306 Plate GB/T 13319 Geometrical Product Specifications (GPS) - Geometrical tolerancing - Positional tolerancing (GB/T 13319-2003, ISO5458:1998, IDT) JB/T 3338.1 Cylindrical helical compression springs for hydraulic parts - Technical conditions MT 76 Emulsifying oil concentrate and high-water content hydraulic fluid used for powered support and prop MT/T 98 Inspection specifications of hose and hose kit for powered support MT/T 986 Quick adapter with U pin and accessories for mine

3 Terms and definitions

The following terms and definitions apply to this Part of GB 25974. 3.1 Nominal pressure The nominal pressure of the valve, which is determined by the basic parameters. 3.2 Nominal flow-rate The nominal flow-rate of the valve, which is is determined by the basic parameters. 3.3 Open pressure of yield valve The opening pressure, which is determined when the yield valve is in use. 3.4 Close pressure of yield valve The stable pressure, which is maintained after the yield valve stops overflowing. 3.5 Close pressure of check valve The stable pressure, which can be maintained after the system is decompressed AND the check valve is closed, when the system supplies liquid to other components through the check valve. 3.6 Open pressure The pressure, at which the liquid starts passing through the valve, after the system

5 Requirements

5.1 General requirements 5.1.1 The nominal flowrate parameters shall meet the requirements of 4.2.7 and 4.2.8. The nominal pressure parameters shall meet the requirements of 4.2.9 and 4.2.10. 5.1.2 The working fluid shall meet the requirements of MT 76. 5.1.3 The temperature of the working fluid shall be in the range of (10 ~ 50) °C. 5.2 Requirements for hydraulic control system 5.2.1 Integrity The hydraulic control system shall be installed, according to the requirements of the design drawings. There shall be neither missing parts nor wrong-installed parts. 5.2.2 Tightness performance The hydraulic control system shall not have abnormal seepage, during normal operation. 5.2.3 Action control The control of the support action by the master control system or neighbor control system, as well as the lowering speed, moving speed, lifting speed of the controlled system shall meet the design requirements; it shall not have any error actions. 5.2.4 Setting pressure and assurance system for setting force The setting pressure of the support shall be greater than 90% of the pressure of the pump station. When the pressure of the column piston cavity is greater than 8 MPa, the assurance system for setting force starts to perform the setting force assurance function; this function shall be terminated at any time. 5.2.5 Liquid supply cut-off The hydraulic control system shall be able to operate on the support, to stop the liquid supply. 5.2.6 Pressure display A device, that can display the pressure in the piston chamber of the column, shall be installed on the support. 5.2.7 System filtration The liquid supply system of the working face shall be equipped with a filter device; a filter shall be installed at the liquid supply inlet of the hydraulic control system of each support. The filtration precision shall meet the design requirements. 5.2.8 Protection from spray liquids When there is a device for spraying liquid in the hydraulic control system, the sprayed liquid shall be protected AND shall not cause harm. 5.2.9 Overload protection When the support is subjected to a large external load, a yield valve shall be installed in the closed liquid chamber or liquid circuit, in the hydraulic control system, to provide overload protection. 5.2.10 On-off of liquid supply The hydraulic control system shall not cause error action of support and abnormal seepage, when the liquid supply is cut off and restored. 5.2.11 Movement speed When the support is working normally, within the reach of the operator's body, the movement speed of any part of the support shall be less than 300 mm/s. 5.2.12 Operating force The operating force of the manual operating device shall be greater than 10 N and less than 130 N. 5.2.13 Back pressure The pressure, in the main return line of the hydraulic control system, shall not exceed 4 MPa; the hydraulic control system shall work normally, under normal back pressure conditions. 5.2.14 Adjustable device The adjustment mechanism of the adjustable device of the hydraulic control system shall have protective measures. 5.2.15 Component removal When the hydraulic control system's components are disassembled, there shall not be a large amount of liquid loss; the tank shall not be required to be drained of liquid. 5.3.1.11 The 6H/6g of GB/T 197-2003 shall be adopted, for the ordinary thread matching; the plated thread matching shall comply with the provisions of GB/T 197- 2003. 5.3.1.12 The ordinary spring shall comply with the provisions of GB/T 1239.1 ~ 1239.4; the pressure regulating spring in the pressure valve shall comply with the provisions of JB/T 3338.1. 5.3.1.13 The position tolerance in the drawing shall comply with the provisions of GB/T 13319. 5.3.1.14 Machining dimensions, without tolerances indicated in the drawings, shall comply with the requirements of grade m in GB/T 1804-2000. 5.3.1.15 The machining shape and position tolerances, for which the tolerances are not indicated in the drawings, shall comply with the requirements of grade K in GB/T 1184- 1996. 5.3.1.16 All castings of the valve shall meet the requirements of GB/T 9439 and GB/T 11352, respectively. 5.3.1.17 See Appendix A, for the technical requirements for the coating of valve parts. 5.3.1.18 The non-metallic parts in the valve shall meet the design requirements of the valve. 5.3.1.19 Standard parts and purchased parts shall meet the design requirements of the valve AND shall have a certificate of conformity. 5.3.1.20 The surface of valve parts shall be smooth, free of burrs, clean, free from bumps and rust spots. 5.3.1.21 In a clean environment, first use kerosene to clean the exterior of the finished valve; then disassemble a set of valves (the directional valve has two sets of valve cores and one valve body), to clean all parts; use a mesh, which has a 40 μm precision, to filter the cleaned kerosene. Dry and weigh the impurities on the mesh. The mass shall be less than 10 mg. 5.3.1.22 The hardness of valve parts shall meet the design requirements. 5.3.2 Performance requirements for yield valves 5.3.2.1 Tightness performance In the range of 2 MPa to 90% of the set pressure, the yield valves shall not have seepage. 5.3.2.2 Actual set pressure The actual set pressure value of yield valves is allowed to have errors. When the open pressure is greater than or equal to 40 MPa, the difference shall be within ±2.5% of the open pressure; when the open pressure is less than 40 MPa, the difference shall be within ±1 MPa. 5.3.2.3 Pressure fluctuations When the flow rate of yield valve is 0.04 L/min, the fluctuation range of pressure to open the yield valve shall not exceed 10% of the open pressure; the maximum pressure fluctuation shall not exceed 110% of the open pressure; the minimum value shall not be less than 90% of the open pressure. 5.3.2.4 Close pressure The close pressure of yield valves shall not be less than 90% of the open pressure. 5.3.2.5 Impact pressure safety When the hydraulic control system generates impact pressure, the yield valve shall not fail, if the impact pressure is not greater than 150% of the open pressure of the yield valve. 5.3.2.6 Strength When the spring is fully adjusted and tightened, the yield valves can withstand 1.5 times the nominal pressure for 3 minutes; there shall be no liquid leakage or damage to parts. 5.3.2.7 Pressure flowrate characteristics When the yield valve flows through the nominal flow, the pressure flowrate characteristics shall meet the following requirements: a) For yield valves, which have a nominal flowrate less than or equal to 16 L/min, the maximum value of the relief pressure shall not be greater than 115% of the open pressure; the minimum value shall not be less than 90% of the open pressure; b) For yield valves, which have a nominal flowrate greater than 16 L/min but less than or equal to 100 L/min, the maximum value of the relief pressure shall not be greater than 120% of the open pressure; the minimum value shall not be less than 90% of the open pressure; c) For yield valves, which have a nominal flow rate greater than 100 L/min, the maximum value of the relief pressure shall not be greater than 125% of the open pressure; the minimum value shall not be less than 90% of the open pressure. 5.3.2.8 Temperature The influence of temperature, on the functions of the inflatable yield valve, shall be 5.3.3.5 Opening pressure The opening pressure of pilot check valves shall not be greater than 1 MPa. 5.3.3.6 Closing pressure The closing pressure of pilot check valves shall not be less than 95% of the liquid incoming pressure. 5.3.3.7 Back pressure safety Pilot check valves shall not malfunction, under normal back pressure conditions. 5.3.3.8 Control pressure The control pressure of the pilot check valve shall be (30 ~ 65)% of the nominal pressure of the pumping station. Pilot check valves shall be able to be unloaded, in the event of a failure of the liquid supply. 5.3.3.9 Durability After 15000 action cycles, pilot check valves shall meet the requirements of 5.3.3.1 ~ 5.3.3.8. After 30000 action cycles, the pilot check valves, which belong to class A valves, shall meet the requirements of 5.3.3.1 ~ 5.3.3.8. 5.3.4 Performance requirements for directional valves 5.3.4.1 directional performance During directional operation, the action shall be flexible; the reversing shall be accurate; there shall be no jamming. 5.3.4.2 Operating force (control pressure, control voltage) The operating force of the manual directional valve shall be greater than 10 N and less than 130 N; the control pressure of the hydraulic directional valve shall meet the design requirements, under the nominal pressure; the control voltage or current of the electronically controlled directional valve shall meet the design requirements. 5.3.4.3 Tightness performance When the directional valve is in the intermediate position, AND the pressure value is within the range of 6 MPa to its nominal pressure, there shall be no leakage. When the directional valve is in the working position, AND the pressure value is within the range of 10 MPa to its nominal pressure, there shall be no leakage. 5.3.4.4 Strength When the directional valve is subjected to a load pressure of 1.5 times the open pressure, in the intermediate position and the working position, there shall be no leakage and damage. 5.3.4.5 Pressure flowrate characteristics When the directional valve flows through the nominal flow, the pressure flowrate characteristics shall meet the following requirements: a) For directional valves, which have a nominal flow rate less than or equal to 125 L/min, the pressure loss of incoming and outgoing liquids shall not be greater than 5 MPa; b) For directional valves, which have a nominal flow rate greater than 125 L/min but less than or equal to 250 L/min, the pressure loss of the incoming and outgoing fluids shall not be greater than 6 MPa; c) For directional valves, which have a nominal flow rate greater than 250 L/min, the pressure loss of the incoming and outgoing fluids shall not be greater than 7 MPa. 5.3.4.6 Back pressure safety Directional valves shall not malfunction, under normal back pressure conditions. 5.3.4.7 Durability The directional valve shall meet the requirements of 5.3.4.1, 5.3.4.2, 5.3.4.4 ~ 5.3.4.6, after 15000 action cycles. Directional valves, belonging to class A valves, shall meet the requirements of 5.3.4.1, 5.3.4.2, 5.3.4.4 ~ 5.3.4.6, after 30000 action cycles. 5.3.5 Performance requirements for shut-off valves 5.3.5.1 Switches When operating the switch, the action shall be flexible AND there shall be no jamming. 5.3.5.2 Operating torque The operating torque of shut-off valves, which have a diameter less than or equal to 25 mm, shall not be greater than 30 N·m. The operating torque of shut-off valves, which have a diameter greater than 25 mm, shall not be greater than 45 N·m. 5.3.5.3 Tightness performance When the shut-off valve is in the cut-off state and the open state, AND the pressure is within the range of 2 MPa to its nominal pressure, there shall be no seepage. 5.3.5.4 Strength The shut-off valve shall not seep or be damaged, when it is subjected to a load pressure of 1.5 times the open pressure, in the cut-off state and the open state. 5.3.5.5 Pressure flowrate characteristics When the shut-off valve flows through the nominal flow, the pressure flow characteristics shall meet the following requirements: a) For shut-off valves, which have a nominal flow rate less than or equal to 125 L/min, the pressure loss of the incoming and outgoing fluids shall not be greater than 1 MPa; b) For shut-off valves, which have a nominal flow rate greater than 125 L/min and less than or equal to 320 L/min, the pressure loss of the incoming and outgoing fluids shall not be greater than 2 MPa; c) For shut-off valves, which have a nominal flow rate greater than 320 L/min, the pressure loss of the incoming and outgoing fluids shall not be greater than 3 MPa. 5.3.5.6 Durability The shut-off valve shall meet the requirements of 5.3.5.1 ~ 5.3.5.5, after 1500 on-off action cycles. 5.3.6 Other valves If other valves contain components, which have similar functions in yield valves, pilot check valves, directional valves or shut-off valves, they shall meet the requirements of 5.3.2, 5.3.3, 5.3.4, 5.3.5, respectively. Others shall meet the design requirements.

6 Test methods

6.1 Test conditions 6.1.1 The working fluid, which is used in the test, shall meet the requirements of 5.1.2. 6.1.2 During the whole process of the test, the temperature of the working fluid shall be kept within the range of (10 ~ 50) °C. 6.1.3 The working fluid used in the test shall be filtered through a filter, which has a precision higher than 25 μm and a magnetic filter device. ......
Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al.


      

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