GB/T 18299-2024Automotive LPG steel cylinder multivalve (English PDF)

2.5 MPa ±

0.2 MPa.

5.1.4 The filling unit shall have at least one non-return valve and one stop valve. The non-return valve shall be of built-in type.

5.1.5 The level indicator shall adopt an indirect liquid level display structure.

5.1.6 The level indicator shall have a dial to indicate the liquid level of liquefied petroleum gas in the cylinder. There shall be a limit filling scale on the dial, marked as "F", and the area exceeding the limit filling scale shall be indicated in red. The pointer on the dial shall swing flexibly.

5.1.7 The multivalve body shall be forged, and the surface of the valve body and all parts of the functional devices shall not have cracks, wrinkles, inclusions, looseness, shrinkage holes, incomplete filling and other defects that may damage the performance of the multivalve and hinder the identification of the marking.

5.1.8 The manufacturer shall specify the design service life of the multivalve, which shall be at least one regular inspection cycle of the cylinder.

5.1.9 The manufacturer shall install an electronically readable mark on the multivalve body.

5.1 Design and process requirements

5.1.1 The multivalve shall be connected by concave and convex flanges, which shall be evenly distributed, and the number of fastening points shall be no less than

6.When the diameter of the pipe opening of the cylinder end of the flange is greater than or equal to phi40 mm, the screw specification shall be no less than M5; when the diameter of the pipe opening of the cylinder end of the flange is less than phi40 mm, the screw specification shall be no less than M

4.The mechanical properties and materials of the screws shall comply with the relevant provisions of GB/T 3098.1, and the performance level shall not be lower than level 8.8.

5.1.2 The inlet and outlet connections of the multivalve shall be in the form of compression fittings.

5.1.3 The safety valve shall be installed in the gas phase interval of the cylinder, and the opening pressure shall be

5.2 Material requirements

5.2.1 Metallic materials The multivalve body material shall be HPb59-1 lead brass, and its mechanical properties and chemical composition shall comply with the requirements of GB/T 4423 and GB/T 5231.Other metal materials, if used, shall be compatible with the liquefied petroleum gas medium, and their mechanical properties shall not be lower than the requirements of HPb59-1.

5.2.2 Non-metallic materials

5.2.2.1 Oxygen aging resistance Rubber seals shall be kept in oxygen with a purity of >=99.5% and a temperature of 70 °C ± 5 °C for 96 hours without visible cracks or damage.

5.2.2.2 Ozone aging resistance When the rubber seal is placed in air at a temperature of 40 °C ± 2 °C and an ozone concentration of 50 mg/L for 72 h at an elongation of 20%, there shall be no cracks.

5.2.2.3 Dry heat resistance After the rubber seal is placed in air at a temperature of 60 °C for 168 hours, the change in tensile strength shall not be greater than 25%, and the elongation change range shall be -30% ~ +10%.

5.2.2.4 Media compatibility Immerse the rubber seals and float in n-pentane at a temperature of 23 °C ± 2 °C for 72 hours. The volume change rate of the rubber seal shall be 0% ~ 20%, and the volume change rate of the float shall be 0% ~ 10%. Then place it in air at 40 °C for 48 h, and the mass loss rate shall not exceed 5%.

5.2.2.5 Low temperature resistance Rubber seals and floats shall be placed in air at a temperature of -40 °C ± 1 °C for 24 hours and shall not show any cracks or other damage.

5.3.1 Multivalve performance

5.3.1.1 Air tightness Carry out air tightness test by immersion method; fill with compressed air or nitrogen; let it stand for 3 minutes at

0.05 MPa and

2.2 MPa, respectively. There shall be no Under the nominal working pressure, when the filling unit is tested for 6 000 cycles, there shall be no abnormal phenomenon and it shall meet the airtightness requirements of 5.3.1.1.

5.3.5 Filling limiter performance

5.3.5.1 Filling limit action and liquid level display Fill compressed air in the gas source pressure range of

0.5 MPa ~

0.8 MPa into the filling limiter. When the float reaches 75% ~ 80% of the volume of the medium in the cylinder, the filling limiter shall automatically close and the pointer of the level indicator shall point to "F".

5.3.5.2 Filling limit performance and liquid level display Control the pressure difference between the inlet pressure of the liquid inlet non-return valve and the pressure inside the cylinder within the range of

0.07 MPa ~ 1 MPa. When the volume of the medium filled into the cylinder reaches 75% ~ 80% of the cylinder, the device shall have an action to limit the fulling, and the pointer of the level indicator shall point to "F". In the filling-limited state, when the pressure difference at both ends is

0.7 MPa, the filling speed shall be less than 500 mL/min.

5.3.5.3 Durability Under the nominal working pressure, when the filling limiter is tested for 6 000 cycles, there shall be no abnormal phenomenon and it shall meet the airtightness requirements of 5.3.1.1.

5.3.6.1 Excess-flow valve action test When

0.6 MPa compressed air is connected to the air inlet of the excess-flow valve, the excess-flow valve shall be able to close automatically.

5.3.6.2 Excess-flow valve performance test When the pressure difference at both ends of the excess-flow valve exceeds

0.1 MPa, the excess-flow valve shall be able to close automatically. When the cause causing the excess-flow valve to close is eliminated, the excess-flow valve shall open automatically. In the flow limiting state, under the pressure difference of

0.1 MPa, the flow rate after flow limiting shall not exceed 1 000 mL/min.

5.3.6.3 Durability Under the nominal working pressure, when the excess-flow valve is tested for 6 000 cycles, there shall be no abnormal phenomenon and it shall meet the airtightness requirements of 5.3.1.1.

5.3.7 Level indicator performance Test the level indicator for 100 000 cycles, and the stroke of each cycle shall not be less than 80% of the actual working stroke. There shall be no abnormal phenomenon and the requirements for filling limit action and liquid level display shall be met.

5.3.8 Stop valve performance Under the nominal working pressure, when the stop valve is tested for 6 000 cycles, there shall be no abnormal phenomenon and it shall meet the air tightness requirements of 5.3.1.1.

6.1 Test conditions

6.1.1 Test environment Carry out the tests specified in this document at an ambient temperature of 15 °C ~ 30 °C, and the laboratory shall be kept shock-proof, moisture-proof, corrosion-proof and well ventilated.

6.1.2 Test medium The medium for static pressure strength test shall be clean water, and the medium for other tests shall be pure dry air or nitrogen, etc.

6.2 Mechanical properties test and chemical composition analysis of metal parts materials The material mechanical properties test method of the multivalve body shall comply with the provisions of GB/T 228.1, and the chemical composition analysis method shall comply with the provisions of GB/T 5121.1, GB/T 5121.3 and GB/T 5121.9.

6.3 Non-metallic material performance test

6.3.1 Oxygen aging resistance test Place the test piece in an aging test device; exhaust the air in the device; fill it with oxygen with a purity of >=99.5%; make the pressure reach

2.1 MPa; raise the temperature to 70 °C ± 5 °C; keep it for 96 h; take it out; visually inspect its changes.