Some standard content:
National Standard of the People's Republic of China
Pneumatic Control Valve
Pneumatic industrial process control valves1 Subject content and scope of application
GB/T 4213-92
Replaces GB421384
This standard specifies the product classification, technical requirements, test methods, and inspection rules of pneumatic control valves (also known as control valves) for industrial process control systems.
This standard applies to various types of pneumatic control valves (hereinafter referred to as control valves) composed of pneumatic actuators and valves. The relevant contents of this standard are also applicable to independent pneumatic actuators and valve assemblies. This standard does not apply to control valves that are subject to radioactive working conditions and other hazardous working conditions. 2 Reference standards
GB9223 Actuator terminology
General technical conditions for instrument packaging
ZB Y0 03
3 Terminology
This standard adopts the terminology specified in GB9223. 4 Product classification
4.1 Classification by the action mode of the regulating valve
Linear stroke regulating valve;
Angular stroke regulating valve.
4.2 Classification by the regulating mode of the regulating valve
Regulating type;
Several type.
4.3 Classification by the action mode of the regulating valve
Air-to-close type;
Air-to-open type.
4.4 Classification by the type of regulating actuator
Pneumatic diaphragm regulating valve;
b. Pneumatic piston regulating valve.
Note: (D) Pneumatic actuators are divided into: a. Pneumatic diaphragm actuators;
b, pneumatic piston actuators.
② Pneumatic actuators are divided into: linear stroke pneumatic actuators;
angular stroke pneumatic actuators according to the output mode.
Approved by the State Bureau of Technical Supervision on August 29, 1992, implemented on April 1, 1993
4.5 Nominal diameter
GB/T 4213- 92
The nominal diameter of the regulating valve should be selected from the following numerical series: 6.10, 15.20, 25, (32), 40, 50, (65), 80, 100, (125), 150, 200, 250, 300, 350, 400, 450, 500, 600.700, 800, 900. 1 000, 1 200, 1 400, 1 600, 1 800, 2 000 mm. Note: The values in brackets are not recommended.
4.6 Nominal pressure
The nominal pressure of the regulating valve should be selected from the following numerical series: 0.1.0. 4.0.6, 1, 1.6, 2.5, 4.6.4.10, 16, 25, 32, 40, 160, 250 MPa.4.7 Input signal range
Standard input pressure signal range of control valve: 20~100kPa; for cut-off control valve, the input signal range can be arbitrarily selected within the rated value of the air source pressure; h.
For control valves with electro-pneumatic valve positioners, the standard input electrical signal range is DC 0~10mA or 4~20mA4.8 Air source
4.8.1 Maximum value of air source pressure
Pneumatic diaphragm control valve: 500kPa;
Pneumatic Piston control valve: 700kPa.
Humidity of air source
The dew point of the air source under the operating pressure should be at least 10C lower than the working environment temperature of the control valve. 4.8.3 Quality of air source
a. The air source should be free of obvious oil vapor, oil and other liquids; b. The air source should be free of obvious corrosive gases, steam and solvents; the number of solid particles contained in the air source of the control valve with a positioner should be less than 0.1g/m, and the particle diameter should be less than 60um, and the oil content should be less than 10 mg/m.
4.9 Normal working conditions
Temperature: -25～+55℃ or -40～+70℃; b. Relative humidity: 5%～100%.
Note: Special temperature grades are allowed, but the temperature value should be a multiple of 10C. 4.10 Signal connection thread
The thread size of the pneumatic actuator and the signal transmission pipeline is M10×1 or M16×1.5, and other sizes can also be used according to user requirements.
4.11 Connection end type and size
a. The connection end type of the control valve is flange, welding or thread; b. The type and size of the connection end of the control valve should comply with the provisions of the relevant national standards. Note: Other standard or specific connection end types and sizes can be used according to user needs. 5 Technical requirements
5.1 Basic error
The basic error of the control valve should not exceed the basic error limit specified in Table 1. The basic error is expressed as the white fraction of the rated stroke of the control valve. 160
Basic error limit
Starting and ending point deviation
Rated stroke deviation
Adjusting type
(Metal seal)
Adjusting type
(Elastic seal)
Cut-off type
GB/T4213—92
Without positioner
With positioner
±2.5±2.5
Measured stroke is greater than rated stroke
Note:) In Table 1, Class A is suitable for regulating valves with special sealing packing and special sealing types; Class E is suitable for general single-seat and double-seat regulating valves; Class B and CD are suitable for regulating valves with various special structures and special purposes. ② For control valves with spring pressure ranges other than 20~100kPa, 40~200kPa and 60300kPa, only the start and end point deviation and rated stroke deviation shall be assessed, and for cut-off control valves, only the rated stroke deviation shall be assessed. 5.2 Hysteresis
The hysteresis of the control valve shall not exceed the provisions of Table 1. The hysteresis is expressed as a percentage of the rated stroke of the control valve. 5.3 Dead zone
The dead zone of the control valve shall not exceed the provisions of Table 1. The dead zone is expressed as a percentage of the input range of the control valve. 5.4 Start and end point deviation
When the input signal in the pneumatic actuator is the upper and lower limit values, the start point deviation of the air-open control valve and the end point deviation of the air-close control valve shall not exceed the provisions of Table 1. The start and end point deviation is expressed as a percentage of the rated stroke of the control valve. 5.5 Rated stroke deviation
The rated stroke deviation of the air-close control valve shall not exceed the provisions of Table 1. The rated stroke deviation of the control valve is expressed as a percentage of the rated stroke.
5.6 Leakage
5.6.1 The leakage of the regulating valve under the specified test conditions shall comply with the provisions of Table 2. 5.6.2 The leakage level of the regulating valve, except for Level I, shall be selected by the manufacturer. However, the leakage level of the regulating valve with a single-seat valve structure shall not be lower than Grade IW, and the leakage level of the regulating valve with a double-seat valve structure shall not be lower than Grade II. 5.6.3 When the leakage is greater than 5×10-3 of the rated capacity of the valve, it shall be guaranteed by the structural design and the product may be exempted from testing. 5.6.4 Leakage shall be specified by the following codes: X1
X1—-~Leakage levels are shown in Table 2 1~VI; X2-
Test medium. G: air or nitrogen, I: water; X3—Test procedure 1 or 2 (see 6.10.2). X2
Leakage level
Test medium
[or G
Note: In kPa.
2)0 is the valve seat diameter. In mm
GB/T 4213-92
Test procedure
Agreed by user and manufacturer
Maximum valve seat leakage
5×10\3×valve rated capacity, 1/h
10\×valve rated capacity, 1/h
J04×valve rated wear, 1/h
5×101×valve rated capacity, 1/h
2X10XApXD.1/h
1.8X10 7xApXD,1/h
3X104XAx (leakage specified in Table 3)
3) For the volume flow of compressible fluid, the absolute pressure is 101.325kPa and the absolute temperature is 273K under standard conditions. Table 3
Seat diameter
Number of bubbles per minute
Note: D The number of bubbles per minute is measured by vertically immersing a tube with an outer diameter of 6mm and a wall thickness of 1mm in water for 5~10 mm depth, the pipe end surface should be smooth, without chamfers and burrs.
(2) If the valve seat diameter differs from the value listed in the table by more than 2mm, the leakage coefficient can be obtained by interpolation under the assumption that the leakage is proportional to the square of the valve seat diameter.
5.6.5 When calculating the allowable value of leakage, the rated capacity of the valve should be calculated according to the formula listed in Table 4. 162
In the table: Q
Q= 4.73K,
Liquid flow rate, m2/h,
GB/T 4213—92
Q, — 0. 1K,1
VG(273 + t)
Gas flow rate under standard conditions, m\/h; rated flow coefficient;
p+pa,kPa;
-absolute pressure before the valve.kPa;
-absolute pressure after the valve, kPa;
Pressure difference before and after the valve, kPa;
Test medium temperature, 20℃;
Gas specific gravity, air=1;
Relative density (water/o=1 within the specified temperature range). 5.7 Sealing of stuffing box and other joints Q = 2.9pK/ VG (273 1)
The stuffing box and other joints of the control valve should ensure no leakage under 1.1 times the nominal pressure. 5.8 Sealing of air chamber
The air chamber of the pneumatic actuator should ensure airtightness. Under the rated air source pressure, the pressure drop in the diaphragm air chamber within 5 minutes shall not exceed 2.5kPa; the pressure drop in each air chamber of the cylinder shall not exceed 5kPa 5.9 Pressure resistance
The control valve shall be subjected to a pressure resistance test of not less than 3 minutes at a test pressure of 1.5 times the nominal pressure. There should be no visible leakage during the test.
5.10 Rated flow coefficient
The value of the rated flow coefficient of the control valve is specified by the manufacturer. The deviation between the measured value and the specified value of the rated flow coefficient of the control valve shall not exceed the specified value ± 10%. When the rated flow coefficient K, ≤ 5, it shall not exceed the specified value ± 20%. 5.11 Inherent flow characteristics
The manufacturer shall specify the inherent flow characteristics of regulating control valves of various specifications, types and throttling component structures with K, ≥ 1 in the form of a diagram or table. When the table is expressed, it should be stated that the specific flow coefficient K, with a stroke h of 0.05, 0.1, 0.2, and then increasing by 0.1 until 1.0, and the manufacturer may also propose flow coefficients other than the above strokes. 5.11.1 The slope deviation of the linear flow characteristic is between the relative stroke h of 0.1 and 0.9. The ratio of the difference between any two adjacent flow coefficient measurements and the measured rated flow coefficient shall comply with the provisions of Table 5.
Relative stroke
In the table: Kw flow coefficient at point n;
flow coefficient at point n-1;
Relative stroke:
GB/T 4213—92
h -- 0. 1~~0. 8
7%～13%
The measured flow coefficient at maximum opening.
5.11.2 The slope deviation of equal percentage flow characteristic h>0.8
When the relative stroke is between 0.1 and 0.9, the decimal logarithm (1g) difference of any two adjacent flow coefficient measurement values shall comply with the provisions of Table 6.
IgKlgK
Adjustable ratio R
h -- 0. 2~0. 8
Slope deviation is +30%
0.13~~0. 07
0.18~0.10
0.19~0.10
0. 22~~0. 12
0.26~~0.14
5.11.3 Deviation of other flow characteristics
Slope deviation is +80%
0. 18~0. 07
0. 25~~0. 10
0.26~0. 10
0. 30~~0. 12
0.36~0.14
Slope deviation is +30%
0.13--0.02
0. 18-~0. 03
0. 190. 03
0. 22~0. 03
0. 26~-0. 04
When the inherent flow characteristics of various control valves are non-linear or equal percentage characteristics, the flow characteristics can be specified according to the following slope deviation or flow coefficient deviation.
a. Slope deviation
The allowable deviation of the slope of the flow characteristics of two adjacent points measured between the relative stroke h0.1~0.9 is 0.5~~~2 times the corresponding inherent flow characteristic slope.
h. Flow coefficient deviation
Between relative stroke h=0.1～0.9, the deviation between the measured flow coefficient of each relative stroke h and the value specified by the manufacturer in the flow characteristics shall not exceed +10 (1/@) 0.2%.
Note: Φ is the relative flow coefficient.
5.12 Working vibration resistance performance
The control valve shall be subjected to a sine sweep vibration test with a vibration frequency of 10~55Hz, an amplitude of 0.15mm, a vibration frequency of 55~150Hz, and an acceleration of 20m/s, and a 30min vibration resistance test at the resonant frequency. After the test, the basic error, hysteresis, air chamber sealing, stuffing box and other joints of the control valve shall still meet the requirements of this standard. 5.13 Action life
The control valve shall be subjected to a life test with accelerated action under specified conditions. After the test, its basic error, hysteresis, air chamber sealing, stuffing box and other joints shall still meet the requirements of this standard; b. The number of actions of various control valves can be selected from the following number series: 2500.4000.10000, 20000, 40000.100000, 160000 times; C.
For P≤6.4MPa, D≤300mm, equipped with pneumatic film actuators, polytetrafluoroethylene molded packing, non-elastic seals GB/T 4213-92
, the number of action life of various types of regulating control valves shall not be less than 100,000 times; d. The action life of special-purpose control valves can be agreed upon by the manufacturer and the user. 5.14 Appearance
The pneumatic actuator and valve of the control valve should be painted or other coatings. Stainless steel and copper valves may not be painted. The arrows and text on the valve body should be painted red. The surface coating should be smooth and intact, without defects such as peeling, bruises and scars, and the fasteners should not be loose or damaged. The valve should have a scale travel pointer or other valve position mark. 5.15 Others
Other corresponding technical requirements may be specified for various types of regulating valves used in dangerous occasions such as fire protection, corrosion protection, high pressure, etc. 6 Test method
6.1 Test conditions and instructions
6.1.1 Reference working conditions
Except for the appearance inspection and other provisions in the clauses, the test should be carried out under the following reference conditions. a.
Temperature: 20±2℃;
Relative humidity: 60%~~70%;
Atmospheric pressure: 86~106kPa;
d. Air source pressure: rated value, with a tolerance of ±1%. 6.1.2 Recommended atmospheric conditions
For tests that are not necessary or impossible to be conducted under reference working conditions, it is recommended to conduct the tests under the following atmospheric conditions: temperature: 15~35C;
relative humidity: 45%~~75%;
atmospheric pressure: 86~106kPa.
During the test, the change in ambient temperature should not exceed 1°C every 10 minutes, and the actual test conditions must be noted in the test report. 6.2 Appearance inspection
Visual inspection is used for inspection.
6.3 Tightness test of stuffing box and other joints Use room temperature water with 1.1 times the nominal pressure, which may contain water-soluble oil or rust inhibitor, to enter the valve body of the regulating valve according to the specified inlet direction, and close the other end. At the same time, make the valve stem reciprocate 1 to 3 times per minute, and the duration is not less than 3 minutes. Observe that there should be no leakage in the stuffing box and other joints of the regulating valve. After the test, the air should be exhausted, and it should be cleaned and dried if necessary. 6.4 Air chamber sealing test
Introduce the air source of the rated pressure specified in the design into the sealed air chamber, cut off the air source, and within 5 minutes, the pressure drop in the membrane air chamber should not exceed 2.5kPa, and the pressure drop in each air chamber of the cylinder should not exceed 5kPa. For the actuator air chamber without the possibility of internal leakage, soapy water can be applied to each seal of the air chamber to check for leakage. For small-sized actuators, they can also be directly immersed in water to check for leakage. 6.5 Basic error test
Steady input the specified input signal into the actuator air chamber (or positioner) in the increasing or decreasing direction, measure the stroke value corresponding to each point, and calculate the error of each point between the actual "signal-stroke" relationship and the theoretical relationship according to formula (1). The maximum value is the basic error. t, l
× 100%
Where: , — error of the i-th point;
l actual stroke of the i-th point,mm;
I:——theoretical stroke of point i, mm; L"—rated stroke of the control valve.
Unless otherwise specified, the test points shall include at least five points: 0, 25%, 50%, 75% and 100% of the signal range. (1)
GB/T 4213--92
The basic error limit of the measuring instrument should not be greater than the basic error limit of the tested control valve. 6.6 Hysteresis test
The test procedure is opposite to that of 6.5. The absolute value of the maximum difference between the positive and negative strokes measured on the same input signal is the hysteresis. 6.7 Dead zone test
a, slowly change (increase or decrease) the input signal until a noticeable stroke change is observed, and record the input signal value at this time;
b, slowly change (decrease or increase) the input signal in the opposite direction until a noticeable stroke change is observed, and record the input signal value at this time:
The absolute value of the difference between the two input signal values a and b is: The dead zone should be tested at 25%, 50% and 75% of the input signal range, and its maximum value shall not exceed the provisions of Article 5.3. 6.8 Start and end point deviation test
Add the upper and lower limit values of the input signal to the pneumatic actuator chamber (or positioner) respectively, measure the corresponding stroke value, and calculate the start and end point deviation according to formula (1).
6.9 Rated stroke deviation test
Input the input signal into the pneumatic actuator chamber (or positioner) to make the valve stem move the full stroke, and calculate the rated stroke deviation according to formula (1). 6.10 Leakage test
6.10.1 The test medium should be a clean gas (air or nitrogen) with a temperature of 5 to 40°C. ) or water. 6.10.2 Test medium pressure:
a. During test procedure 1, it should be 0.35MPa. When the allowable pressure difference of the valve is less than 0.35MPa, use the allowable pressure difference specified in the design: b. During test procedure 2, it should be the maximum working pressure difference of the valve. 6.10.3 Test signal pressure:
The pneumatic actuator should be adjusted to a working state that meets the requirements. During test procedure 1, the signal pressure of the air-to-open control valve actuator should be zero; the signal pressure of the air-to-close control valve actuator should be the upper limit of the input signal plus 20kPa; the signal pressure of the cut-off control valve actuator should be the design specified value. During test procedure 2, the actuator signal pressure should be the set value. The specified value is calculated. When testing a valve without a pneumatic actuator, a test thrust device should be attached, and the force applied should not exceed the maximum valve seat sealing force specified by the manufacturer.
6.10.4 Test medium flow direction:
The test medium should flow into the valve according to the specified direction. The valve outlet can be directly connected to the atmosphere or connected to a low-pressure head loss measuring device for outlet ventilation. The leakage can be measured only after confirming that the valve and the downstream connecting pipes are completely filled with the medium and the leakage is stable. 6.10.5 Measurement error:
The measurement error of leakage and pressure should be less than ±10% of the reading value. 6.10.6 The leakage level, test medium, test procedure and maximum leakage should comply with the provisions of Table 2. 6.11 Pressure resistance test
Use room temperature water with 1.5 times the nominal pressure, which may contain water-soluble oil or rust inhibitor, and input it into the valve body of the regulating valve in the direction of the valve body, and close the other end, so that all valve cavities under pressure during operation can withstand the test pressure for not less than 3 minutes at the same time. There should be no visible leakage in the pressure-bearing part of the regulating valve.
During the test, the linear regulating valve should be in the fully open position, and the angular stroke regulating valve can be partially opened. The test equipment should not subject the regulating valve to external stress that will affect the test results. If necessary, the components that may be damaged and are not related to the test, such as bellows, diaphragms, packings and other parts, can be removed for testing. The accuracy of the pressure instrument used for the test shall not be lower than Class 2.5, and the upper limit of the measurement range shall not be greater than 4 times the test pressure.
6.72 Flow test
6.12.1 Test assembly
Standard test section
GB/T 4213--92
The standard test section shall consist of two straight pipe sections as shown in Table 7. The nominal diameter of the connecting pipe shall be the same as the nominal diameter ID of the test regulating valve. b. Pressure tapping hole
The pressure tapping hole shall be arranged according to the requirements of Table 7 and the structure of the figure. Its hole diameter d shall be one tenth of the nominal diameter, with a minimum of 3mm and a maximum of 12mm, and a length L of 2.5~5d. The pressure tapping hole diameters before and after the valve shall be the same. The pressure tapping hole shall be located in a horizontal position to avoid air and dust accumulation. Its center line shall intersect vertically with the center line of the pipeline. The edge of the hole shall not protrude from the inner wall of the pipe and shall be sharp and free of burrs. c. Installation of regulating valve
The regulating valve to be tested shall be connected to the test pipeline according to the specified installation position. The center line of the pipeline shall be coaxial with the center line of the outlet and inlet of the test valve. The inner diameter of the sealing seal shall be accurate and its position shall not cause protrusion on the inner wall of the pipeline. Table 7
Straight pipe section
Standard test section layout
Diagram of medical hole
6.12.2 Test medium
The test medium shall be water at 5～40℃.
6.12.3 Test pressure difference
Pressure hole distance before valve
Pressure hole distance after valve
Straight pipe section
The pressure difference before and after the regulating valve shall be greater than or equal to 35kPa. When the rated flow coefficient of the valve is very small and very low, as long as the turbulent flow can be maintained, that is, the valve Reynolds number R is greater than 4×10°, other suitable pressure differential values can be selected, but the pressure differential value used in the actual test should be recorded. 6.12.4 Measurement error
GB/T 4213-92
The method for measuring the following parameters should make the error no greater than the following specified values: flow rate: actual flow rate ±2%, repeatability should be within 0.5%; a.
b, pressure difference: actual pressure difference ±2%;
c, temperature: test medium temperature ±1C, during the test, the fluid inlet temperature change should be guaranteed to be within ±3C d.
Valve stroke: rated stroke + 0.5%.
6.12.5 Flow coefficient calculation formula
Wherein; Q—liquid flow, m/h;
△p—pressure difference before and after the valve, kPa;
Vap/p/pn
p/p. Relative density (water within the specified temperature range/1). 6.12.6 Measurement of flow coefficient
(2)
Adjust the stroke of the regulating valve to the corresponding test point, measure the flow value under three pressure differences greater than or equal to 35kPa (the increment is not less than 15kPa), and calculate the flow coefficient respectively. The maximum value of the three values obtained in each flow test should not be greater than 4% of the minimum value. The flow coefficient of each stroke should be the arithmetic mean of the three values and rounded to three significant figures. 6.12.7 Rated flow coefficient measurement
Measure and calculate the rated flow coefficient at the rated stroke value of the control valve according to the method in Article 6.12.6. When the control valve D% ≥ 300mm, the test can be temporarily exempted.
6.12.8 Measurement of inherent flow characteristics
Measure the flow coefficient when the relative stroke = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 according to the method in Article 6.12.6 and the ratio of the measured rated flow coefficient is the relative flow coefficient. From this, the flow characteristic curve of the control valve "relative stroke-relative flow coefficient\" can be drawn. When the control valve D300 min, the test is temporarily exempted. 6.13 Vibration resistance test
The regulating valve is installed on the vibration test bench according to the working position, and 50% signal pressure is input. According to the frequency and amplitude or acceleration specified in Article 5.12, the frequency sweep vibration test is carried out in the X, Y and Z directions. The frequency sweep should be continuous and logarithmic, and the sweep speed is about 0.5 times the range per minute.
The regulating valve should also be subjected to a vibration resistance test at the resonant frequency for 30±1min. If there is no resonance point, it should be vibrated at 150Hz for 30±1min. After the test, each item should be measured according to Articles 6.3, 6.4, 6.5 and 6.6. Performance, the control valve with a weight of more than 50kg can be exempted from the test. 6.14 Action life test
The control valve is placed in an ambient temperature of 5 to 40°C. The specified air source pressure is passed into the air chamber of the pneumatic actuator at a frequency of not less than once per minute. The regulating control valve performs 80% of the rated stroke excluding the closed position. After the acceleration test, the various performances are measured according to 6.3, 6.4, 6.5.6.6; the cut-off control valve performs the rated stroke reciprocating action. After the acceleration test, the various performances are measured according to 6.3 and 6.4.
7 Inspection rules
7.1 The factory inspection and type inspection of various types of control valves shall be carried out in accordance with the technical requirements and corresponding test methods specified in Table 9. When the pneumatic actuator and valve are shipped separately, they shall be inspected in accordance with the corresponding provisions in Table 9. 168
Basic errorwwW.bzxz.Net
Deviation of starting and ending points
Rated travel deviation
Leakage
Sealing of stuffing box and other joints
Sealing of air chamber
Pressure resistance
Rated flow coefficient
Inherent flow characteristics
Working vibration resistance
Action life
Note: "△" is the inspection item.
GB/T4213—92
Regulating type
Cut-off type
Actuator
② During the validity period of the type inspection of the control valve, the pneumatic actuator or valve can be exempted from type inspection when it is shipped separately! \ 7.2
Type inspection of control valves shall be carried out in the following cases: a.
Trial production and identification of new products and old products transferred to the factory for production; when there are major changes in structure, materials and processes after formal production, which may affect product performance; during normal production, regular inspection or periodic inspection after accumulating a certain amount of output; when the product is resumed after long-term suspension; when there is a significant difference between the final inspection result and the last type inspection; when the national quality supervision agency proposes the requirement for type inspection. 8 Marking, packaging and storage
8.1 Marking
8.1.1 Nameplate marking
A nameplate should be clearly fixed at the appropriate position of the pneumatic actuator and marked with the following: a.
Manufacturer name or Guangdong standard;
Product model:
Nominal diameter;
Nominal pressure;
Working temperature;
Spring pressure range (signal pressure range for cut-off type); rated stroke;
Rated flow coefficient;
D300mm free of test
Free of test when weight ≥50kg
Flow characteristics (none for cut-off type);
Valve body material;
GB/T 4213--92
Design position number (can also be marked on a separate nameplate); product manufacturing number;
Year and month of product manufacturing.
Note: For small-sized control valves, if the size of the nameplate is limited and all the marks cannot be accommodated, some marks can be omitted, but items a, b, h, k, l, and m must be marked.
8.1.2 Valve body marking
The arrow indicating the flow direction of the medium and the value of *Dr\ should be cast or punched on the valve body of the control valve. The "P" and the value can also be marked on the nameplate firmly fixed to the valve body. 8.2 Packaging
Before packaging, all uncoated external machined surfaces of the control valve should be coated with anti-rust oil or other anti-rust measures should be taken. The valve outlet and inlet doors and the threaded holes of the signal transmission pipe should be sealed and properly packaged according to ZBYO03 to ensure that they are not damaged during transportation. The technical documents packed with the control valve are: a. Product factory certificate;
|b, product manual;
c. Packing list.
8.3 Storage
The regulating valve should be stored in a room with an air temperature of 5-40℃ and a relative humidity not exceeding 90%. The air should not contain harmful impurities that may corrode the regulating valve.
Additional instructions:
This standard is proposed by the National Technical Committee for Standardization of Industrial Process Measurement and Control. This standard is under the jurisdiction of the 1st Technical Committee of the National Technical Committee for Standardization of Industrial Process Measurement and Control. This standard was drafted by the Shanghai Industrial Automation Instrumentation Research Institute. The main drafter of this standard is Wang Kecheng.
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