This part of GB 25974 specifies the terms and definitions, classification, requirements, test methods, inspection rules, marking, packaging and storage for hydraulic control system and valves of powered support for coal mine (hereinafter referred to as support).
This part is applicable to various supports for coal mine and other hydraulic control system and valves with supporting equipment, including various hydraulic control systems, yield valves, pilot check valves, directional valves and shut-off valves.
This part is not applicable to valves in pressurizer, power set legs and ram (i.e. foot valve of power set legs).
2 Normative References
The following standards contain provisions which, through reference in this standard, constitute provisions of this standard. For dated references, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, the parties entering into agreement according to this standard are encouraged to research whether the latest editions of these references apply. For undated references, their latest editions are applicable to this standard.
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 Tolerance of Shape and Position - Unnoted Tolerance (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 Hot Coiled Helical Springs - Technical Specifications
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 (Applicable to Inspection of Stability for Productive Process)
GB/T 3452.1 Liquid 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)
