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GB/T 12242-2021: Pressure relief devices - Performance test code
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Basic data | Standard ID | GB/T 12242-2021 (GB/T12242-2021) | | Description (Translated English) | Pressure relief devices - Performance test code | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | J16 | | Word Count Estimation | 66,660 | | Issuing agency(ies) | State Administration for Market Regulation, China National Standardization Administration | GB/T 12242-2021: Pressure relief devices - Performance test code---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Pressure relief devices - Performance test code
ICS 13.240
CCSJ16
National Standards of People's Republic of China
Replace GB/T 12242-2005
Pressure relief device performance test method
Released on 2021-03-09
2021-10-01 implementation
State Administration of Market Supervision and Administration
Issued by the National Standardization Management Committee
Table of contents
Foreword Ⅰ
1 Scope 1
2 Normative references 1
3 Terms and definitions 1
4 General 6
5 Pressure release device action performance and displacement test 6
5.1 Test equipment and instruments 6
5.2 Measurement method 11
5.3 Test installation requirements 13
5.4 Test procedure 14
5.5 Calculation of results 28
5.6 Test summary report 29
6 In-use test and constant pressure test on workbench 31
6.1 Measuring instruments and measuring methods 31
6.2 Test procedures in use 32
6.3 Constant pressure test procedure on the workbench 33
6.4 Seal test 34
6.5 Calculation of results 34
6.6 Test summary report 35
Appendix A (Informative) Test Report Form 37
Appendix B (Informative) Test Summary Report Form 54
Appendix C (informative) Example of determining flow error 58
Pressure relief device performance test method
1 Scope
This document specifies the test methods for the operating performance test (including mechanical characteristics), displacement and resistance coefficient of the pressure release device.
This document is applicable to test procedures with various import and export conditions, and the test medium is steam and gas whose physical properties are known.
(Air) or liquid (water); including reclosing and non reclosing pressure relief devices, as follows.
a) safety valve,
b) Bursting disc device,
c) Break/shear pin device,
d) Fusible plug device.
When the parties involved in the test agree to accept the terms of this document, this document can also be applied to other pressure relief devices.
2 Normative references
The contents of the following documents constitute the indispensable clauses of this document through normative references in the text. Among them, dated quotations
Only the version corresponding to that date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to
This document.
GB/T 2624.1 Use a differential pressure device installed in a circular cross-section pipe to measure the flow of fluid in a full pipe. Part 1.General principles and
Claim
GB/T 2624.2 Use a differential pressure device installed in a circular cross-section pipe to measure the flow of fluid in a full pipe. Part 2.Orifice plate
GB/T 12241 General requirements for safety valves
GB/T 12243 spring direct load safety valve
3 Terms and definitions
The following terms and definitions defined in GB/T 12241 apply to this document.
3.1 General terms
3.1.1
Pressure relief device
A device used to prevent the pressure of the internal medium from rising to exceed the predetermined maximum pressure when the pressure vessel is in an emergency or abnormal situation.
3.1.2
Pressure relief valve pressure relief valve; PRV
A valve used to prevent the pressure of the internal medium from rising to exceed the predetermined maximum pressure when the pressure vessel is in an emergency or abnormal situation.
3.1.3
Field test fleldtesting
In order to determine some or all of the working characteristics of the pressure relief device, the test of the pressure relief device installed on the system.
3.1.4
In-service testing
In order to determine some or all of the working characteristics of the pressure relief device, use system pressure or use an external pressure source (with or without auxiliary
Lifting device) A test of a pressure relief device installed on the system that is protecting the system.
3.1.5
Displacement test flowcapacitytesting
Determining the operating characteristics of the pressure relief device includes a test to measure the displacement.
3.1.6
Benchtesting
A test on a pressurized system to determine the set pressure of the pressure relief device and the tightness of the closure.
3.2 Types of pressure relief devices
3.2.1
Reclosing pressure-Relieving devices
Designed as a pressure release device that is driven by the inlet static pressure and re-closes after returning to normal working conditions.
Note. The structure types are spring direct load type, pilot type, power operation type.
3.2.2
Non-reclosing pressure relief device
A pressure release device that remains open after an action can provide a means of manual reset.
Note. Non-reclosing pressure release devices include rupture discs, breaking pins, bending pins, shear pins, and fusible plugs.
3.2.2.1
Rupture disk device
The function of a non-reclosing pressure release device driven by the static pressure difference between the inlet and outlet of the device is realized by the blasting of the pressure-bearing piece.
3.3 Characteristic dimensions of pressure relief device
3.3.1
Dischargearea
The minimum cross-sectional area of the fluid passage when the valve is discharged.
3.3.2
Nozzlearea
The minimum cross-sectional area of the flow path from the inlet end of the valve to the sealing surface of the closing member.
3.3.3
Nozzlediameter
Corresponds to the diameter of the flow channel area.
3.3.4
Curtainarea
When the valve flap rises above the valve seat, the cylindrical or conical discharge channel area is formed between the sealing surfaces.
Note. The area of the curtain is shown in Figure 1.
3.3.7
Seatangle
The angle between the valve axis and the sealing surface.
Note. The bevel angle of the sealing surface of the flat sealing valve is 90°.
3.4 Characteristic dimensions of non-reclosing pressure relief devices
3.4.1
Net flow area netflowarea
The area of the flow rate is determined after the non-reclosing pressure release device operates.
Note. The (minimum) net flow area of a rupture disc is the calculated net area after it is completely ruptured, and it has an appropriate tolerance, because some structural parts of the rupture disc
May reduce its net circulation area.
3.5 Action and displacement characteristics of the pressure release device
3.5.1
Set pressure
The inlet static pressure raised by the pressure release device, under which the device exhibits the definition of opening pressure, sudden jump pressure, and starting leakage pressure
One of the action characteristics of force, burst pressure, and breaking pressure (for a specific device design, the applicable action characteristics are determined by the device manufacturer.
set).
3.5.2
Overpressure
The pressure increase exceeding the set pressure of the pressure release valve, at which the safety valve reaches the opening height specified by the manufacturer.
Note. The excess pressure is usually expressed as a percentage of the set pressure.
3.5.3
Re-seating pressure
After the pressure release valve is discharged, the disc contacts the valve seat again, that is, the pressure when the opening height becomes zero.
3.5.4
Blowdown
The difference between the set pressure and the return pressure.
Note. The opening and closing pressure difference is expressed as a percentage of the set pressure or in pressure units.
3.5.5
Discharge pressure
Set pressure plus over pressure.
3.5.6
Rated discharge pressure flow-ratingpressure
The inlet static pressure when measuring the displacement of the pressure release device.
3.5.7
Backpressure
The static pressure generated at the outlet of the pressure relief device due to the presence of pressure in the exhaust system.
3.5.8
Built-upbackpressure
The pressure generated at the outlet of the device as the medium flows through the pressure relief device into the discharge system.
3.5.9
Superimposedbackpressure
The pressure that exists at the outlet of the pressure relief device immediately before it operates.
Note. The additional back pressure is caused by other pressure sources in the exhaust system.
3.5.10
Burst pressure
When the bursting disc device operates, its inlet static pressure.
3.5.11
Specified burst pressure of bursting disc device specified burst pressure of a rupture disk device
The inlet static pressure of the bursting disc device is increased, and the bursting disc is designed to burst at this pressure at a specified temperature.
3.5.12
Breaking pressure
When the broken pin device, bend pin device or shear pin device operates, its inlet static pressure.
3.5.13
Secondary pressure
The pressure existing in the passage between the actual discharge section of the pressure relief valve and the outlet.
3.5.14
Simmerpressure
An inlet static pressure lower than the set pressure of the pressure release valve. Under this pressure, the sealing surface of the safety valve closing part can be audible or
The visually perceived medium is leaking, but there is no measurable displacement.
Note. The front discharge pressure is only applicable to safety valves for compressible media.
3.5.15
Theoretical displacement theoreticalrelieving(discharge)capacity
An ideal nozzle whose minimum cross-sectional area of the flow channel is equal to the flow channel area of the pressure relief valve or equal to the net flow area of the non-reclosing pressure relief device
The calculated displacement.
Note. The theoretical displacement is expressed in units of weight or volume.
3.5.16
Measuredrelieving(discharge)capacity
The displacement of the pressure relief device measured at the rated discharge pressure.
Note. The measured displacement is expressed in units of weight or volume.
3.5.17
Rated displacement ratedrelievingcapacity; certifieddischargecapacity
The measured displacement is allowed to be used as the reference part of the pressure relief device by the applicable regulations or standards.
3.5.18
Equivalentcalculatedcapacity
The calculated displacement of the pressure release device when the use conditions such as pressure, temperature or medium are different from the applicable conditions of the rated displacement.
3.5.19
Rated displacement coefficient ratedcoefficientofdischarge
The ratio of rated displacement to theoretical displacement.
3.5.20
Frequency hopping chatter
The disc of the pressure release valve moves back and forth quickly and abnormally, and the disc contacts the valve seat during the movement.
3.5.21
Flutter
The disc of the pressure release valve moves back and forth quickly and abnormally, and the disc does not touch the valve seat during the movement.
3.5.22
Reference conditions
The conditions of the test medium specified by the applicable standards or by the agreement between the test parties can be used to unify the results of the displacement test.
4 General
4.1 The measurement deviation of the test in this document is specified as follows. For the displacement test, the deviation of the final displacement measurement should not exceed the measured value.
±2.0%; for the action performance test, the deviation of the pressure measurement should not exceed ±0.5% of the measured value; for the test in use and the setting on the workbench
For pressure test, the deviation of pressure measurement should not exceed ±1.0% of the measured value.
4.2 For the tests specified in this document, the test device should have the pressure and sufficient capacity required by the tested pressure release device, and should meet
The pressure release device or pressure release valve discharge pressure test needs, and the test duration should meet the required action under stable conditions
The need for performance and displacement data. The test operating conditions shall be maintained in accordance with the requirements of the test procedure.
4.3 On-site installation or abnormal operating conditions may adversely affect the function of the pressure relief device. Evaluate the pressure relief device in
The applicability and reliability under such conditions are outside the scope of this document.
4.4 If there is a big difference between the temperature of the medium used in the pressure release device test and the temperature the device is subjected to in actual use, the
The functional characteristics in actual use, such as opening pressure, opening and closing pressure difference, and burst pressure, will be different from those obtained from the test. Consider these differences
The content of making appropriate amendments to the pressure relief device under test conditions does not belong to the scope of this document.
4.5 This document provides recommended test procedures and test instruments. As long as other test procedures and test instruments can be proved to have at least the
If the document requires equivalent accuracy and reliability, it can be used. If other procedures and instruments are to be used, the test should be obtained before the test
Written consent of the parties concerned.
4.6 The test results shall be reported according to measurement and calculation. Only when the test fully complies with the mandatory requirements of this document can it be designated
It is a test conducted in accordance with this document.
4.7 The parties involved in the test shall deal with the design and overpressure protection of the piping system and components, the safe discharge of the pressure release device during the test, and the general
Special consideration is given to the high noise that accompanies the emission to ensure that the test device meets the minimum mandatory requirements.
4.8 The parties to the test shall reach an agreement on the following matters before conducting the test.
a) Test purpose;
b) Test site, test parties, test and test supervisors;
c) The benchmark condition of the test fluid under the rated discharge pressure;
d) Test methods, instruments and equipment used in the test (the calibration of the instrument should be in accordance with 5.1.2);
e) The number, diameter, type, condition, source, set pressure and expected displacement of the tested device;
f) Written test procedures, the procedures should include the observations and readings that should be recorded in order to meet the purpose of the test.
4.9 Qualifications and responsibilities of test supervision test personnel.
a) The test supervisor should have received education in thermodynamics and fluid mechanics, and have practical experience in fluid flow measurement.
Experience in supervising trials.
b) During the test, the test supervisor should observe the test conditions throughout the process and the operating personnel should fully understand the correctness of these operations.
Definite method.
c) The test supervisor shall be responsible for ensuring that the written test procedures are followed, and shall sign the test report or verification report.
5 Pressure release device action performance and displacement test
5.1 Test equipment and instruments
5.1.1 Test device
The layout of the test device is shown in Figure 2~Figure 7 and Figure 9.
To ensure its accuracy within the expected use range.
5.1.2.6 Steam calorimeter
The steam calorimeter should be calibrated at the time of its installation and within the specified period. When the measurement result shows that the reading is obviously wrong
At time or after reinstallation, calibration should be performed again.
5.1.2.7 Flowmeter combination
The calibration of the flowmeter should include the actual pipes and all accessories on the upstream and downstream sides of the flowmeter.
The connection between the container and the valve. The calibration should be completed before the execution of the formal test by the method of comparison, that is, the flow measurement value should be calibrated in advance.
The value measured by the accurate flowmeter device is compared, and the latter's calibration is done with the aid of the original device or mechanism. About pre-calibration
The agreement of the flow meter device should make the deviation of the final overall test result within ±2.0%. The calibration should be at the smallest,
Performed at middle and maximum flow. For valves with different inlet connection forms, the connections should be made by laboratory personnel during manufacture or purchase.
Calibration by the operator. In addition, the flow meter device should be recalibrated at least once every 5 years as described above. This recalibration should include the use of at least two
Various sizes of connectors. Calibration records should be kept and audited by relevant parties. If a change is made to the equipment, it should be assessed that the change may affect the system.
For the impact of system calibration, a new calibration should be performed when deemed necessary.
5.1.3 Adjustments in the test
When collecting data, no adjustments should be made to the pressure release device. After any change or deviation of the test conditions, adequate
Time allows the flow, temperature and pressure to stabilize before collecting data.
5.1.4 Test records and test results
The test record should include all observations, measurements, meter readings and meter calibration records (when needed) of the test object. Original test record
The records should be kept by the institution conducting the test. Copies of all test records should be submitted to all parties to the test. The correction and correction value should be loaded into the test record separately
record. The test summary report shall be made in accordance with the provisions of 5.6.
5.1.5 Measurement error
Preliminary tests should be carried out to determine that the specified instruments and procedures can meet the error limits specified in 4.1 for the final displacement measurement.
limit. An error analysis after the test should also be performed, unless all parties to the test agree and verify that the specified instruments and procedures including the discreteness of the data are based on
The test specifications are used and executed to confirm that the error determined by the preliminary test is still valid after the test. The error determination should be determined by the shape of the test chamber
Documented for review.
5.2 Measurement method
5.2.1 Atmospheric pressure measurement
Atmospheric pressure should be measured with a barometer. When calculating including displacement, if the rated discharge pressure of the pressure relief device is equal to or higher than
At 0.15MPa (gauge pressure), the average atmospheric pressure of the test area can meet the accuracy requirements of this document. On this occasion, the recorded
The pressure can be average atmospheric pressure.
5.2.2 Temperature measurement
The requirements for temperature measurement are as follows.
a) According to the operating conditions, temperature measurement can use glass tube liquid thermometer, bimetal thermometer, resistance thermometer or thermoelectric
I. The glass tube liquid thermometer should be inserted into the sleeve, and the bimetal thermometer, resistance thermometer or thermocouple can be directly inserted into the tube
In the channel, it can also be inserted into the casing. When the temperature is lower than 150℃, the temperature measuring device should be directly inserted into the pipeline without additional casing.
b) When taking any temperature measurement, the following measures should be taken.
1) Except for the measured medium, there should be no large heat transfer between the temperature measuring device and the outside world due to radiation or conduction.
2) The immediate vicinity of the insertion point and the exposed part of the temperature measuring device should be insulated.
3) The insertion depth of the small diameter pipe temperature measuring device should pass through the center line of the pipe; when the pipe diameter exceeds 300mm, the temperature measuring device
The device should be inserted into the media stream at least 150mm deep.
4) On pipelines that transport compressible fluids, the temperature measuring device should be installed when the maximum medium flow rate does not exceed when performing flow measurement.
30m/s. If this is not possible, the temperature reading may need to be corrected to the appropriate static or full temperature.
5) The insertion position of the temperature measuring device should be such that the measured temperature represents the temperature of the flowing medium.
c) When using a glass tube mercury thermometer to measure temperature, the thermometer should have a graduated rod. When the measured temperature is the same as the ambient temperature
When the difference is greater than 5℃ and the mercury is partially exposed, the exposed rod should be corrected, or an exposed rod thermometer should be used.
d) When using a thermometer casing, the casing should be thin-walled and its diameter should be as small as possible. There should be no corrosion or debris on the outside of the casing. casing
The inside should be filled with appropriate fluid, but mercury should not be used. If mercury is used, appropriate precautions should be taken.
e) If a thermocouple is used, it should have a soldered hot end, and it should be calibrated in the expected range of use together with its external wires.
The thermocouple should be made of materials suitable for the measured temperature and medium. The electromotive force should be measured with a potentiometer or millivoltmeter.
The cold junction of the thermocouple should be formed by using an ice bath (reference standard) or by installing a compensation circuit on the potentiometer.
5.2.3 Pressure measurement
The requirements for pressure measurement are as follows.
a) The pressure measuring point should be arranged in the area where the flow is basically parallel to the pipe wall or container wall. When measuring a static pressure difference of less than 0.1MPa,
A liquid pressure gauge can be used.
b) The pressure of the test vessel should be the static pressure measured through the pressure tap shown in Figure 2.
c) The back pressure should be the static pressure measured through the pressure tap shown in Figure 3, Figure 5 and Figure 6.
d) If there is a water level difference or other level difference between the pressure measurement point and the pressure gauge, the pressure reading should be appropriately corrected.
5.2.4 Flow measurement
5.2.4.1 The methods for measuring the displacement of the pressure release device are.
a) Subsonic inferred flowmeter, including orifice plate, flow nozzle and venturi tube;
b) Sound velocity inferred flowmeter, including plug flow nozzle;
c) Volume method or gravimetric method for directly collecting the discharge medium or its condensate.
5.2.4.2 The following methods shall be used to measure the displacement of the pressure release device as appropriate.
a) The steam flow rate when the back pressure is atmospheric pressure, using the method 5.2.4.1a) or 5.2.4.1c);
b) The steam flow rate when the back pressure is higher than the atmospheric pressure, use the method 5.2.4.1a);
c) The flow of air or gas when the back pressure is atmospheric pressure, using the method 5.2.4.1a) or 5.2.4.1b);
d) The flow of air or gas when the back pressure is higher than atmospheric pressure, using the method 5.2.4.1a);
e) The liquid flow rate when the back pressure is atmospheric pressure, using the method 5.2.4.1a) or 5.2.4.1c);
f) The liquid flow rate when the back pressure is higher than the atmospheric pressure, use the method 5.2.4.1a).
Note. During the test, the back pressure may be higher than the atmospheric pressure. Pay attention to the use of the sound velocity inferred flowmeter.
5.2.4.3 One-time measuring element.
a) The primary measuring element should be placed on the upstream side of the inlet of the pressure relief device under test. Installation requirements and meter location are shown in Figure 2.hole
The ratio of the plate hole diameter to the pipe inner diameter should be between 0.2 and 0.7.A measuring element should be checked before the test to confirm its
Clean and undamaged.
b) The pressure difference and fluid temperature before and after the primary measurement element should be measured with a meter connected to the position shown in Figure 2.
c) There should be a long enough straight pipe section in front of the primary measurement element to ensure a uniform flow velocity distribution in the flow channel close to the element.
cloth. In order to ensure reliable pressure measurement, the outlet side of the primary measurement element should also have the same nominal size as the inlet pipe.
Long straight pipe section.
d) The flow should remain stable during the displacement measurement, and the total pulsation value (double amplitude) displayed on the differential pressure gauge should not be greater than the measured differential pressure
Of 2%. When the pulsation value is large, the cause of the pulsation should be eliminated. Trying to reduce the pulsation by the meter itself is not allowed.
e) Measures should be taken to avoid the use of excessively humid steam that can cause unstable conditions. When testing with steam, throttling heat can be used
The meter measures the steam dryness (see 5.2.5).
f) The installation and flow measurement of the orifice plate should meet the requirements of GB/T 2624.1 and GB/T 2624.2.
5.2.5 Steam dryness measurement
The dryness of flowing steam can be measured with a throttling calorimeter. The installation of the calorimeter is shown in Figure 2 and Figure 3.Its steam sampling tube
It can also be directly installed on the container, as long as the sampling tube extends into the flow channel directly below the center line of the inlet nozzle of the pressure release device, and it is not lower than
The horizontal centerline of the test vessel. When the calorimeter measurement conditions are not available, it should be ensured that the flowing steam has a superheat below 10°C.
5.2.6 Turn on height measurement
Open height measurement requirements.
a) Open or perforated bonnet structure, if the upper end of the valve stem can be exposed during the test, you can set a scale with an appropriate range
The disc indicator is set on the top of the valve to indicate the displacement of the valve stem. The end of the stem of the closed valve should not be exposed, and appropriate
Measures to indicate, read or record the valve stem displacement on the outside of the valve cover or cap. In any case, the measuring device should not be
Place additional load on the valve stem or hinder the movement of the valve.
b) When using steam to test a valve with additional back pressure, the open high indicator may show erroneous readings. When asked to try
When the test results have high accuracy, the opening height indication caused by thermal expansion in the measurement should be distinguished from the actual opening height of the valve.
5.2.7 Conditions under which correction can be carried out
5.2.7.1 Steam. The reference condition is dry saturated steam. In the test, the steam condition at the inlet of the pressure release device should be that the steam dryness is not small
At 98% or overheating is not more than 10℃.
5.2.7.2 Water. The reference condition is 18℃~24℃. The temperature range of the water at the inlet of the pressure release device in the test should be 5℃~50℃.
5.2.7.3 Air and other gases. the reference condition is 13℃~24℃. Air or other gas at the inlet of the pressure release device during the test
The temperature range should be -18℃~93℃.
5.2.7.4 If the test condition is not within the range of 5.2.7.1~5.2.7.3, the correction from the actual test condition to the reference condition cannot be carried out.
The actual test pressure should not be corrected.
5.2.8 Medium composition
A medium with well-defined physical properties should be used as the test medium. If there is any doubt about the physical properties of the fluid, physical experiments or chemical
Learn to analyze to determine.
5.3 Test installation requirements
5.3.1 The pressure release device under test shall use connecting accessories (flange type, thread type or welding type, etc.). The acceptable internal cross-sectional shape is shown in
Figure 8) Install directly on the test vessel. As long as it does not affect the accuracy of the test results, other connection accessories can also be used; no matter which one is used
To connect in any way, it should be ensured that the inner diameter of the connection accessory test vessel interface is greater than the inner diameter of the pressure release device under test.
5.3.2 For the test where the back pressure before discharge is atmospheric pressure, the test arrangement should be such that the medium is directly discharged from the pressure release device to the atmosphere or the condenser (see
Figure 2, Figure 3 and Figure 4). When using a discharge pipe, the pipe size should be at least equal to the outlet size of the pressure relief device. Support for discharge pipe
Should be independent of the pressure relief device, its support method should not affect the action of the pressure relief device. Measures should be taken to ensure the pressure relief device
And the discharge pipeline is strong enough to withstand the combined force generated by the discharge.
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