This document specifies the product classification and general requirements, technical requirements, test methods, inspection rules, marking, packaging and storage of pneumatic control valves for industrial process control systems.
This document is applicable to all kinds of pneumatic control valves composed of pneumatic actuators and valves (hereinafter referred to as "control valves"). This document is also applicable to independent pneumatic actuators and valve assemblies.
Control valves with specific working conditions required by the country for radioactive or other hazardous working environments shall be implemented in accordance with this document.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 12224 General requirements for industrial steel valves
GB/T 13384 General specifications for packing of mechanical and electrical product
GB/T 17213 (All parts) Industrial-process control valves
GB/T 17213.2-2017 Industrial-process control valves - Part 2-1: Flow capacity - Sizing equations for fluid flow under installed conditions
GB/T 26640 Specification for minimal thickness of the shell of valves
GB/T 26815 Terminologies for industrial-process measurement and control instruments - Terms of final controlling elements
3 Terms and definitions
For the purposes of this document, the terms and definitions defined in GB/T 17213 (all parts) and GB/T 26815 apply.
4 Product classification and general requirements
4.1 Classification according to the function of control valve
According to the function of the control valve, it can be classified into:
a) regulating type;
b) on-off type.
4.2 Classification according to the operation mode of control valve
According to the operation mode of the control valve, it can be classified into:
a) linear motion;
b) rotary motion.
4.3 Classification according to the mode of action of control valve
According to the mode of action of the control valve, it can be classified into:
a) air-to-close;
b) air-to-open.
4.4 Classification according to the type of control valve actuator
According to the type of control valve actuator, it can be classified into:
a) pneumatic diaphragm type;
b) pneumatic piston type.
Note 1: Pneumatic actuators are classified into:
a) pneumatic diaphragm actuator;
b) pneumatic piston actuator.
Note 2: Pneumatic actuators are classified into:
a) linear motion pneumatic actuator;
b) rotary motion pneumatic actuator.
4.5 Nominal size (DN or NPS)
The alphanumeric designation consists of the letters DN or NPS followed by a dimensionless number.
The value following the nominal diameter DN of the control valve shall be selected from the following preferred values:
Note 1: The dimensionless number of the nominal diameter is directly related to the characteristic dimensions such as the bore diameter or outer diameter of the end connector.
Note 2: The dimensionless number does not represent a measurable value and shall not be used for calculation purposes except where specified in the relevant standard.
Note 3: See Annex A for the correlation between DN and NPS.
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Product classification and general requirements 4.1 Classification according to the function of control valve 4.2 Classification according to the operation mode of control valve 4.3 Classification according to the mode of action of control valve 4.4 Classification according to the type of control valve actuator 4.5 Nominal size (DN or NPS) 4.6 Nominal pressure (PN series) or pressure class (Class series) 4.7 Input signals 4.8 Gas sources 4.9 Normal working conditions 4.10 Signal connecting pipe thread 4.11 Type and size of connecting end 5 Technical requirements 5.1 Compressive strength 5.2 Tightness of packing box and other connections 5.3 Leakage 5.4 Tightness of air chamber 5.5 Basic error 5.6 Hysteresis 5.7 Initial-final signal offset 5.8 Dead band 5.9 Rated travel offset 5.10 Rated flow coefficient 5.11 Inherent flow characteristic 5.12 Resistance to operating vibration 5.13 Action life 5.14 Wall thickness of valve body 5.15 Chemical composition of valve body and bonnet 5.16 Surface quality 5.17 Others 6 Test methods 6.1 Test condition and description 6.2 Compressive strength 6.3 Tightness of packing box and other connections 6.4 Leakage 6.5 Tightness of air chamber 6.6 Basic error 6.7 Hysteresis 6.8 Initial-final signal offset 6.9 Dead band 6.10 Rated travel offset 6.11 Rated flow coefficient and inherent flow characteristic 6.12 Test of resistance to operating vibration 6.13 Action life test 6.14 Wall thickness of valve body 6.15 Chemical composition of valve body and bonnet 6.16 Surface quality 7 Inspection rules 7.1 End-of-manufacturing test 7.2 Type test 8 Marking, packaging, and storage 8.1 Marking 8.2 Packaging 8.3 Storage Annex A (Informative) Correspondence of nominal diameters Annex B (Informative) Calculation examples of valve seat leakage
