GB/T 15382-2021General specification for gas cylinder valves (English PDF)

5.1 Material requirements...

5.1.2 Valve body material

5.1.2.1 The valve body material shall be made of materials that will not change from plasticity to brittleness (such as copper alloy, austenitic stainless steel, aluminum alloy, nickel alloy, etc.), meanwhile it shall meet the design strength requirements of the valve body. The performance of the material shall comply with corresponding national standards.

5.1.2.2 When selecting brass material for the valve body, its copper content shall be in the range of 57.0% ~ 65.0%, lead content shall be in the range of 0.8% ~ 1.9%, iron content shall be <= 0.5%. The mechanical properties of the material shall not be lower than those specified in GB/T 4423.

5.1.3 Operating mechanism and operating device materials

5.1.3.1 The valve operating device shall have sufficient strength and fire resistance, which should be made of aluminum alloy material.

5.1.3.2 The materials of the valve stem, valve, connecting plate shall have sufficient strength and corrosion resistance. The valve stem used for liquid chlorine medium shall be made of stainless steel material, that is resistant to hydrochloric acid corrosion, or materials with higher resistance to hydrochloric acid corrosion.

5.1.3.3 The spring placed inside the valve should be made of corrosion-resistant stainless steel.

5.1.3.4 The diaphragm piece of the diaphragm valve shall be made of elastic stainless steel material, or a combination of media corrosion-resistant material and elastic stainless steel material.

5.1.4 Rubber seal materials

5.1.4.1 Oxygen aging resistance The rubber seal shall be kept in oxygen at a pressure of (2.3 ± 0.2) MPa and a temperature of (70 ± 5) °C for 96 hours; there shall be no visible cracks or aging.

5.1.4.2 Low temperature resistance The rubber seal shall be kept in air at a temperature of (-40 ± 2) °C for 24 hours; there shall have no cracks or other damage.

5.1.5 Non-metallic materials in contact with oxygen or strongly oxidizing gases

5.1.5.1 Non-metallic seals, lubricants, sealants and other materials that come into contact with oxygen or strongly oxidizing gases shall be flame retardant.

5.1.5.2 Non-metallic seals, lubricants, sealants and other materials that come into contact with oxygen or strongly oxidizing gases should be subjected to self-ignition tests, according to the test methods specified in

GB/T 31481. Their self-ignition temperature shall be at least 100 °C higher than the maximum operating temperature.

Note: The maximum operating temperature refers to the highest temperature the valve may be at during use (such as when inflated).

5.1.5.3 Non-metallic seals, lubricants, sealants and other materials that come into contact with oxygen or strongly oxidizing gases shall be subjected to pressure impact tests under pvt pressure, according to the test methods specified in

GB/T 31481; it shall not react with oxygen.

5.1.6 Materials of safety pressure relief devices The material of the safety pressure relief device shall comply with the requirements of GB/T 8337 or GB/T 16918.

5.2 Design and process requirements

5.2.1 The valve shall be able to operate normally within the ambient temperature range of -40 °C ~ +60 °C. This temperature range can be appropriately expanded for a short period of time (such as inflating). When the cylinder is used for a long time at a lower or higher temperature, the supplier and the buyer shall sign an agreement and make it clear in the supplier's instructions.

5.2.2 The manufacturer shall specify the design service life of the valve, which is at least one periodic inspection cycle of the gas cylinder.

5.2.3 The valve's inlet and outlet should adopt connection types and sizes that comply with the provisions of GB/T 8335 and

GB/T 15383. The accuracy of the valve's inlet and outlet connection threads shall meet the requirements of GB/T 8335, GB/T 197,

GB/T 7307. The accuracy of metric threads shall at least meet the requirements of 6 g and 6 H; the accuracy of cylindrical pipe threads shall at least meet the requirements of Class B.

5.2.4 The closing direction of the valve shall be designed to be clockwise, so that the valve can be opened or closed flexibly regardless of whether there is pressure in the cylinder. For valves used for oxygen or strongly oxidizing gases, they shall be rotated more than circle when fully opened.

5.2.5 For valves that use a handle to open and close, the maximum length of the handle shall ensure that the valve stem and the sealing surface of the valve are not damaged, meanwhile an adjustable wrench should not be used.

5.3.10 Valve tightness Use a non-metallic sealed dissolved acetylene cylinder valve. Burn the valve seal with a flame. Install the valve parts into the valve without any cleaning. Close the valve with a torque of not more than 12 Nm. The leak rate under the pressure of pvt shall not be greater than 50 cm3/h.

5.3.11 Hydrochloric acid corrosion resistance The valve stem of the liquid chlorine cylinder valve shall undergo a hydrochloric acid corrosion resistance test. After the test, close the valve using a torque of To. The valve shall have no leakage at room temperature and pvt pressure; the valve stem shall not break.

5.3 Performance requirements...

5.3.12 Operation performance of safety pressure relief device

5.3.12.1 The design of the safety pressure relief device of the valve shall comply with the requirements of

GB/T 33215. A bursting disc device, a fusible alloy plug device, a bursting disc-fusible alloy plug composite device or a spring-type pressure relief device can be installed as needed.

5.3.12.2 The operating pressure of the bursting disc device, the setting pressure and the reseating pressure of the spring-type pressure relief device shall comply with the provisions of GB/T 33215.

5.3.12.3 The operating temperature of the fusible alloy plug device should be as follows:

a) , used for valves with nominal working pressure not greater than

b) (100 ± 5) °C, used to dissolve acetylene cylinder valve;

c) (110 ± 5) °C, used for valves with nominal working pressure greater than

3.45 MPa and not greater than 35 MPa.

5.3.12.4 The operating pressure and operating temperature of the bursting disc-fusible alloy plug composite device shall comply with the provisions of

5.3.12.2 and 5.3.12.3.

6.1 General principles for testing

6.1.1 Test environment Unless there are other special requirements, the test shall be conducted at room temperature of 15 °C to 30 °C; the lab shall be kept shockproof, moisture-proof, anticorrosive, well ventilated.

6.1.2 Test medium In the absence of other special requirements, except for the pressure resistance test medium which is clean water, the other test media are pure dry air or nitrogen.

6.1.3 Pressure gauge for testing The accuracy of the pressure gauge used for testing shall be no less than level 1.6; the range of the pressure gauge shall be 1.5 ~ 2 times the test pressure.

6.2 Inspection of material mechanical properties and chemical composition The mechanical properties of the valve body material shall be tested in accordance with the provisions of GB/T 228.1; the chemical composition should be tested using spectroscopic methods, to check whether the mechanical properties and chemical composition of the material comply with the provisions of

5.1.2.1 and 5.1.2.2. Where dispute arbitration occurs, the inspection methods specified in the corresponding material standards shall be used.

6.3 Oxygen aging resistance test Place 5 rubber seals in the aging test device. Remove the air in the device. Fill it with oxygen at a purity of >= 99.5%. Bring the pressure to (2.3 ± 0.2) MPa. Raise the temperature to (70 ± 5) °C. Take it out after keeping it for 96 hours. Visually check whether the result meets the requirements of 5.1.4.1.

6.4 Low temperature resistance test Place the 5 rubber seals in a test chamber at a temperature of (-40 ± 2) °C. After keeping it for 24 hours, take it out and put it on a steel mandrel which has a diameter

1.2 times the inner diameter of the rubber seal. Visually inspect, to see whether the results comply with the provisions of 5.1.4.2.

6.5 Inspection of connection dimensions

6.5.1 The connection size of the valve's air inlet and outlet shall be tested using measuring tools that meet the corresponding thread and dimensional accuracy requirements; check whether the results comply with the provisions of 5.2.3. Install the valve on the test device. Slowly increase the closing torque, until the valve mechanically fails. Then disassemble the valve. Check whether each part meets the requirements of 5.3.3.3. Install the valve on the test device. Slowly increase the opening torque, until the valve mechanically fails. Disassemble the valve. Check whether each part meets the requirements of 5.3.3.3.

6.8.3.2 Failure torque test of handle valve Install the valve on the test device. Slowly increase the closing torque, until the valve mechanically fails. Record the torque. Then install the other valve on the test device. Slowly increase the opening torque, until the valve mechanically fails. Record the torque. Take the smaller of the two as the Tf value of the valve. This value is used to calculate the To and Te values in Table 1.

6.9.1 Air tightness test for type test

6.9.1.1 Overview The air tightness test during type test shall be carried out according to the following requirements:

a) The valve shall undergo external air tightness test, internal air tightness test, vacuum air tightness test (if required);

b) The valve shall be tested, item by item at the temperatures (room temperature, - 40 °C, -20 °C, +65 °C) and test sequence specified in Table 4, at the pressure specified in Table 2;

c) When the valve is tested for low-temperature and high-temperature air tightness, it shall be kept at this temperature for at least 30 minutes, to ensure that the valve has reached the corresponding temperature before leak testing;

d) When the valve is undergoing a -20 °C air tightness test, it can be directly raised from -40 °C to -20 °C. There is no need to first raise to room temperature and then cool down;

e) After the valve has passed the -20 °C air tightness test, it shall be raised to room temperature through natural conditions, then raised to +65 °C;

f) When conducting the internal air tightness test at -40 °C, the valve shall be closed first at room temperature and then cooled down.

6.9.1.2 External air tightness test Install the valve on the test device. Block the air outlet of the valve. Open the valve to any open state at the torque of Te, start (use Te, end after the endurance test) in Table 1. Apply the pressure specified in Table 2 from the air inlet of the valve. Maintain the specified pressure for at least 1 minute. Check whether the result meets the requirements of 5.3.4.

Note: The air tightness test during exit-factory inspection is only conducted at room temperature; the test pressures are pvt,

0.05 MPa, vacuum degree (if required), respectively.

6.9.1.3 Internal air tightness test Install the valve on the test device. Close the valve using the torque of Te, start in Table 1 (use Te, end after the endurance test). Remove the valve outlet seal. Fill the valve inlet with the pressure specified in Table 2. Maintain the pressure for at least 1 minute. Check whether the result meets the requirements of 5.3.4.

Note: The air tightness test during exit-factory inspection is only conducted at room temperature; the test pressures are pvt,

0.05 MPa, vacuum degree (if required), respectively.

6.9.1.4 Vacuum air tightness test Install the valve on the test device. Connect the valve outlet to the vacuum pump. Connect the valve inlet to the vacuum gauge. Keep the valve in the open state. Turn on the vacuum pump. Wait until the pressure in the valve reaches the set value. Close the valve using the torque of Te, start (use Te, end after the endurance test) in Table 1. Hold it for 5 minutes. The pressure in the valve shall not rise.

6.17 Action test of safety pressure relief device

6.17.1 Operation test of bursting disc device Install the valve on the test device. Keep the valve at a temperature of (60 ± 2) °C. Fill it with clean air or nitrogen to 90% of the minimum burst pressure. Set the pressure increase rate to the point where the minimum indication value can be accurately read on the pressure gauge. Hold the pressure for not less than 5 seconds. Then pressurize steadily and continuously. When increasing the pressure, the minimum indication of the pressure gauge shall be accurately read; the pressure increasing rate per second shall not be less than 0.1% of the bursting pressure, until the bursting disc ruptures. This process shall not exceed 2 minutes. Check whether the results comply with the provisions of 5.3.12.2.

6.17.2 Action test of fusible alloy plug device The action temperature test, flow temperature test, extrusion resistance test of fusible alloy plug device shall be carried out in accordance with the methods required by GB/T 8337. Check whether the results comply with the provisions of 5.3.12.3.

6.17.3 Action test of bursting disc-fusible alloy plug composite device The flow temperature of fusible alloy plugs is tested according to the method required by GB/T 8337. Check the results to see if they comply with the provisions of 5.3.12.4. materials, corresponding tests shall be added;

c) When changing the valve body material, all tests that cause changes in test conclusions due to changes in chemical composition and mechanical properties need to be added;

d) When changing the material of the handwheel, an additional sample needs to be added for endurance test (no need for subsequent air tightness test), integrity inspection of the handwheel and the contact surface between the handwheel and the valve stem, opening and closing test, fire test;

e) When changing the diameter of the handwheel, it is necessary to add endurance test, internal air tightness test, parts integrity check, opening and closing torque test;

f) When changing the basic design dimensions of the valve parts (such as the diameter of the valve stem, the pitch of the valve stem or valve thread, the valve diameter, the size of the O-ring, the thickness of the diaphragm, etc.), it is necessary to add all tests caused by the change;

g) When changing the metal materials of the valve operating mechanism parts (such as pressure cap, valve stem, diaphragm, spring), all tests caused by the change need to be supplemented;

h) When changing the gas channel structure of the valve body (such as diameter and flow channel angle), all tests caused by the changes need to be supplemented.

7.2.4 When providing samples, the manufacturer shall at least provide the following information to the type testing agency:

a) Technical documents, including design drawings (which shall indicate the valve structure, grease usage, applicable gas medium for the valve, working pressure, design service life, whether it is used for gas cylinders with or without fixed protection devices, etc.), operating instructions (which shall include various torque values, etc.), parts list, material technical requirements, etc.;

b) Valve identification information;

c) Media compatibility statement that meets the requirements of ISO 11114-1 and ISO 11114-2. If the material selected for the valve does not fall within the scope of application of ISO 11114-1 and ISO 11114-2, a compatibility certificate of the selected material shall also be provided;

d) The opening pressure and closing pressure range of the residual pressure device.