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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
GB 25974.3-2010
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 ??m 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...