This standard specifies the terms and definitions, product classification and basic parameters, technical requirements, test methods, inspection rules, marking and packaging and storage of valve positioners for industry-process control systems (hereafter referred to as "positioners").
This standard is applicable to various conventional pneumatic positioners used matching with pneumatic actuator, being capable of accepting standard analog input signal or digital signal and having pneumatic output, the electric-pneumatic positioners and the electric-pneumatic positioners with microprocessors.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 3836 (all parts) Explosive Atmospheres
GB 4208-2008 Degrees of Protection Provided by Enclosure (IP Code)
GB/T 13384-2008 General Specifications for Packing of Mechanical and Electrical Product
GB/T 17213.6 Industrial-process Control Valves - Part 6-1: Mounting Details for Attachment of Positioners to Control Valves - Positioner Mounting on Linear Actuators
GB/T 17213.13 Industrial-process Control Valves - Part 6-2: Mounting Details for Attachment of Positioners to Valves - Positioner Mounting on Rotary Actuators
GB/T 17626.2 Electromagnetic Compatibility - Testing and Measurement Techniques - Electrostatic Discharge Immunity Test
GB/T 17626.3 Electromagnetic Compatibility - Testing and Measurement Techniques-Radiated Radio-frequency Electromagnetic Field Immunity Test
GB/T 17626.4 Electromagnetic Compatibility - Testing and Measurement Techniques - Electrical Fast Transient/Burst Immunity Test
GB/T 17626.8 Electromagnetic Compatibility - Testing and Measurement Techniques - Power Frequency Magnetic Field Immunity Test
GB/T 18271.1-2000 Process Measurement and Control Devices - General Methods and Procedures for Evaluating Performance - Part 1: General Considerations
GB/T 22137.1-2008 Valve Positioners for Use in Industrial-process Control System - Part 1: Methods of Evaluating the Performance of Valve Positioners with Pneumatic Outputs
GB/T 22137.2-2008 Valve Positioners for Use in Industrial-process Control System - Part 2: Methods of Evaluating the Performance of Intelligent Value Positioners with Pneumatic Outputs
GB/T 25480-2010 Basic Environmental Conditions and Testing Methods for Transportation and Storage of Instruments
GB/T 26815-2011 Terminologies for Industrial Process Measurement and Control Instruments - Terms of Final Controlling Elements
3 Terms and Definitions
For the purposes of this document, the following terms and definitions apply.
3.1
valve positioner
a kind of positioner which is mechanically associated with valve or actuator and automatically adjusts the pressure output to the actuator to ensure the specified accurate relation between valve position and input signal
[Definition in 2.7.3 of GB/T 26815-2011]
3.2
single acting positioner
positioner having only one output signal
[Definition in 2.7.4 of GB/T 26815-2011]
3.3
double-acting positioner
positioner having opposite output signals in two action directions
[Definition in 2.7.5 of GB/T 26815-2011]
4 Product Classification and Basic Parameters
4.1 Product Classification
4.1.1 Classification according to structure
According to composition structure, the positioners are classified into:
a) Conventional positioner;
b) Positioner with microprocessor.
4.1.2 Classification according to the actuators equipped
According to the actuators equipped, the positioners are classified into:
a) Positioner equipped with pneumatic diaphragm actuator;
b) Positioner equipped with pneumatic piston actuator;
c) Positioner equipped with other pneumatic actuators.
4.1.3 Classification according to the mode of output action
According to the mode of output action, the positioners are classified into:
a) Single acting positioner;
b) Double-acting positioner.
4.1.4 Classification according to working mode
According to working mode, single acting positioners are classified into:
a) Positive acting positioner;
b) Reverse acting positioner.
Note: Positive acting positioner - both input signal and output pressure are increased;
Reverse acting positioner - the input signal is increased while the output pressure is reduced.
4.1.5 Classification according to output travel
According to output travel, the positioners are classified into:
a) Linear positioner;
b) Rotary positioner.
4.1.6 Classification according to service environment
According to service environment, the positioners are classified into:
a) Ordinary type positioner;
b) Explosion-proof type positioner.
4.1.7 Classification according to input signal
According to input signal, the positioners are classified into:
a) Pneumatic valve positioner;
b) Electric-pneumatic valve positioner.
4.1.8 Classification according to input signal range
According to input signal range, the positioners are classified into:
a) Positioner with standard input signal range;
b) Positioner with split input signal range.
4.1.9 Classification according to output characteristics
According to output characteristics, the positioners are classified into:
a) Positioner with linear output characteristics;
b) Positioner with equal percentage output characteristics;
c) Positioner with quick-opening output characteristics;
