Valve positioners for use in industrial-process system.Part 2:Methods of evaluating the performance of intelligent valve positioners with pneumatic outputs

2Scope / Description

The design review and testing specified in GB/T 22137.2 is to measure and determine the static and dynamic performance, intelligence degree and communication capability of single-acting or double-acting intelligent valve positioners. These tests can be used for positioners that receive standard analog circuit input signals (specified in GB/T 3369.1 and GB/T 3369.2) and/or positioners that transmit digital signals via a data communication link and have a pneumatic output. A smart valve positioner, as defined in Chapter 3, is an instrument that realizes its function through digital techniques of data processing, decision generation, and two-way communication, and can be equipped with additional sensors and additional functions to complement its main function. The performance test of the intelligent valve positioner needs to install the positioner and connect it with one or more actuators/valve components. In the formed combination, some specific characteristic parameters need to be carefully selected and reported, such as: size, stroke , friction (hysteresis), filling type, spring assembly and air supply pressure of the pneumatic part. It should be noted that the performance of the positioner in the combination is related to the actuator, especially when determining the operating range (dynamic response and stability) of the positioner, it needs to be tested on actuators of different sizes. The evaluation methods provided in this section are intended for manufacturers to determine the performance of their products, and for users or testing laboratories to verify equipment performance. It is recommended that manufacturers of smart locators use this section in the early development stages. In order to provide guidance for the evaluation of the design of intelligent valve positioners, this part provides: - a checklist for reviewing the hardware and software design of intelligent valve positioners according to a structured method; - measurement and qualification of intelligent valve positioners under different environmental and operating conditions The test method of device performance; - The method of obtaining data for the report. This section also applies to non-intelligent valve positioners with microprocessors but not capable of bidirectional communication. In this case, the assessment should be reduced to a limited performance test procedure and a brief structural review.