The new GB regulating valve pneumatic control valve door national standard GB4213-84 "pneumatic regulating valve door general technical conditions" was released on March 21, 1984, to be implemented on January 1, 1985. The standards were modified in 1992 modified the standard code for GB/T4213-92, in October 1993. The standard according to IEC international standards, and combined with the specific situation of China enacted. The original execution date of the department standard implementation of the new GB void.
Comparison of old and new standards, there are the following differences:
(1) new GB "life" indicators, a total of 14 personality indicators:
A basic error; 2 hysteresis; 3 dead; 4 always point deviation; rated travel deviation; 6 leakage; 7 stuffing and other connections at the tightness: tightness of the gas chamber; 9 Compressive strength; 10 rated flow coefficient; inherent flow characteristics; 12 anti-vibration; 13 action life; 14 appearance.
(2) new GB select the performance cost ratio requirements for basic error, hysteresis, deadband, always point deviation, rated stroke the deviations divided into A, B, ...... H 8 levels in order to meet different functions depending on valve best indicator level. The old standard for each valve corresponds to a unique indicator of a lack of flexibility.
(3) new GB leak amount specified as A, B ...... F, 6 level, the highest class F, the number of bubbles per minute. Only one level of the old standard, high-pressure valve provisions of the leakage is not realistic. copyright dedecms
(4) The flow characteristics of error checking methods, the new national standard test slope method.
(5) new GB the old standard flow capacity renamed flow coefficient. Its value is the old standard uniform provisions, the new national standard determined by the manufacturer itself, more convenient new product designs have been finalized.
(6) of the basic error, hysteresis test points divided by the old standard of 10 test points changed to five test points.
(7) new GB regulating valve gas source and ambient temperature. The air source should be clean, dry air, does not contain corrosive gases, solvents, or other liquids. A regulating valve with a positioner, the gas source contained in the number of solid particles should be less than 0.1 g / m, and the particle diameter should be greater than 3μm, and the oil content should be less than 1 ppm.
Regulating valve Ambient temperature -25 ~ +55 ℃ or -40 to +70 ° C.
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