GB 26787-2011Safety specifications of line regulator used in welding, cutting and allied processes (English PDF)

4.1 Metal Materials

4.1.1 Acetylene or metallic material having similar chemical properties of the gas contact

With acetylene or a metallic material having similar chemical properties of the gas contact, the copper content of the material may not exceed 70%.

Retardant material metal pieces (including sintered metal parts) application does not contain copper processing.

When using silver brazing copper alloy, silver content not exceeding 46% of the copper content shall not exceed 37%.

4.1.2 Contact with oxygen in the metal material

Various elements can not be in contact with oxygen-containing oil. Springs and other moving parts should be in contact with oxygen oxidation-resistant material and may not be to be coated.

4.2 Non-metallic materials

4.2.1 Solvent resistance

Non-metallic materials in contact with acetylene (e.g., as a sealing member and lubricant material) should be resistant to acetone and dimethylformamide (DMF) solvent properties. Solvent resistance requirements in Appendix A.

4.2.2 N-pentane-resistant performance

Propane, butane and methyl acetylene - propadiene mixture of non-metallic material of the contact (e.g., as a sealing member and lubricant material) should be a Adequate resistance properties of n-pentane. Pentane-resistant performance requirements in Appendix A.

4.2.3 Oxygen-resistant performance

All components in contact with oxygen should not contain may react violently with oxygen substances such as hydrocarbon solvents and oils.

Can be used in maximum working pressure and temperature, the lubricant can be used in oxygen.

5.1 Mechanical strength

5.1.1 Structural Strength

Design and manufacture of pressure reducer should be applied to ensure that the pressure specified in Table 2 in the high and low pressure chamber after not lead to permanent deformation.

Table 2 Test pressure

Regulator type high-pressure chamber pressure chamber Oxygen and other compressed gases, p2 1MPa 1.2 × 1.5 × p1 3MPa 6MPa

5.1.2 Security

Design and manufacture of pressure reducer shall ensure that the intermediate chamber pressure chamber or two-stage pressure reducer with full gas bottle in direct communication, the pressure reducer valve Paul Held in the open position and the closed outlet connection (such as with additional shut-off valve or blind plug closing), high-pressure gas can be safely cut-off or discharge.

5.2 Safety valve

5.2.1 General

In addition to all of those pressure regulator for acetylene, it should provide a safety valve for discharging pressure over the outlet pressure.

When the outlet pressure is less than or equal to 1.5 times the rated outlet pressure, safety valve should be sealed; when the amount is greater than the outlet pressure of 1.5 to 2 times when the set outlet pressure, exhaust valve should open. Traffic safety valve should QRV>=0.5Q1 acetylene gas pressure reducer in any case are pRV shall be equal to 0.3MPa.

After the safety valve opening, the outlet pressure drops greater than p2 should be closed. For users, the safety valve is not adjustable.

5.2.2 Valve installation position

General safety valve and pressure reducer directly connected to a low pressure chamber.

5.3 Pressure regulating means

The design of this device should ensure that the regulator can be used safely, it is recommended in Appendix B of the structure.

When using the regulator set pressure relief valve should always be kept sealed.

5.4 Oxygen Regulator

Oxygen Regulator design, fabrication and assembly should be done inside the blasting does not occur. All parts and accessories should be thoroughly cleaned before assembly Degreasing. After the assembly should be able to withstand 20 times the inlet pressure of oxygen continuous impact shock, fire and may not appear charred internal damage.

5.5 Gauge

5.5.1 Flag

Measuring oxygen gauge dial shall be marked in red the word "oil" or, as no oil flags shown.

1 oil ban flag

5.5.2 Energy release

When the spring tube rupture, leakage of gas pressure gauge should enable positive direction away from the discharge pressure gauge, pressure gauge glass should be no damage.

6.1 Test conditions

6.1.1 Total properties testing equipment

All piping and flow test equipment connected to the control valve diameter should be greater than the test pressure reducer caliber.

6.1.2 Type of gas

The test shall be at an ambient temperature of 23 °C ± 2 °C, relative humidity of 50% ± 5%, ambient pressure of 0.086MPa ~ 0.106MPa Under conditions, with oil-free air or nitrogen.

Explosion test oxygen regulator should be used oxygen.

In all cases, the test should apply the maximum moisture content of not more than 0.005% of the gas, the corresponding dew point -48 °C.

6.2 Mechanical strength test

Warning. The test should take protective measures.

6.2.1 The structural strength test During the test, replace the plug with a hole safety valve and pressure gauge, pressure reducer diaphragm instead of sheet metal. Table 2 applying regulations on the high-pressure chamber and a low pressure chamber Given water pressure test 5min. After the test check the dimensions and shape without permanent deformation (for example, the use of contrast measurement).

6.2.2 Safety Test

The test pressure reducer valve should remain open persistent or dismounted. Pressure gauge and replace the safety valve when the test hole plug, close the outlet. through Manually open the valve too quickly, applying a pneumatic pressure p1 to pressure reducer imports.

Regulator should be no cracks. Such as cracks, debris shall not be discharged. The mounting pressure safety device allows gas through this apparatus.

6.3 Safety valve

During the test, open or remove the pressure reducer valve, closing the outlet reducer. <=1.5p2 pressure exerted by imports, at this pressure, Safety valve should be sealed. Then the pressure relief valve to open, the pressure at <=2p2, recording the pressure relief valve opens. Then Pressure increased pRV = 2p2, and the measured flow QRV at this pressure safety valve.

6.4 Explosion test (Oxygen Regulator)

Each of the three prototype testing, so that the oxygen pressure reducer valve inlet subjected to a pressure shock wave generated by the shock of industrial oxygen (pure oxygen at least 99.5% of; hydrocarbons <=0.0001%). Test systems should be installed preheated oxygen equipment, oxygen bottles and a quick opening valve. Figure 2 shows the test rig an example.

1 --- oxygen source;

2 --- inlet valve;

3 --- then oxygen cylinder pressure sensor;

4 --- Ti thermocouple;

5 --- oxygen cylinder with a preheating device (such as a water bath, electric heating apparatus);

6 --- fast opening valve;

7 --- outlet valve;

8 --- takeover;

Pressure sensor 9 --- then the outlet valve;

10 --- measuring point;

11- reducer experimental prototype.

Figure 2 test bench blasting

Before the test, the test pressure measured at point 10, increased from atmospheric pressure to the test time required shall be 20 0-5ms (see Figure 2).

Test pressure may be measured at point 9 from the sample at a secret cover 30mm ~ 40mm (see Figure 2). Every time you want to record at least two pressure shock wave. Quick opening between the valve and the regulator took the test length of 750mm, an inner diameter of 14mm. Before testing, the prototype should be placed in the room temperature. The test gas is preheated to 60 °C ± 3 °C during the test, the test pressure for this temperature should be 1.2 × p1.

20 by the pressure of each test interval of 30s shock (see Figure 3).

Each pressure shock wave continued 10s. After each exert a pressure shock wave through the inlet end of the valve should be restored to the atmospheric pressure reducer.

Between each shock pressure, atmospheric for at least 3s.

In one set of experiments, the inlet pressure drop shall not exceed 3% p1 values.

Figure 3 test interval

Shall be tested under the following conditions.

a) pressure reducer valve in the fully open position, the outlet closed;

b) pressure reducer valve in the fully closed position.

Regulator in the test may not fire. After the test is completed, three prototype should disassemble and inspect all internal parts and surfaces. Internal There are not damaged and burned reception.

6.5 Test pressure regulating means

If necessary, check the pressure adjustment screw is not removable. For acetylene regulator, closing the gas outlet, it does not set pressure it may be greater than 0.15MPa.