1. Test preparation
Fit the fire-resistant breathing valve correctly on the test stand, the device shall not leak and the inner wall of the test tube shall be smooth and smooth.
2. Detection medium
The test medium for opening pressure, ventilation rate and leakage of fire-resistant breathing valve is air, with absolute pressure of 0.1Mpa, temperature of 20 C, relative humidity of 50% and density of 1.2kg/m3. If air is not in this state, it should be converted into gas in this state.The test medium for the pressure of the fire-resistant breathing valve body is 5-35 deg. C. clear water.
3. Air pressure detection
First check its leakage rate, then check its sensitivity and ventilation rate one by one.
4. Water pressure detection
The pressure of fire-resistant breathing valve for hydrostatic test is 0.2Mpa and the holding time is 10min.
5. Pressure detection
Fit the fire-resistant breathing valve on the connecting flange of the gas storage tank, adjust the valve so that the pressure in the gas storage tank gradually increases or decreases, adjust the valve disc to make it open, read out the pressure value on the connected micro-pressure gauge, read it once every minute, then turn the disc 90 times respectively.°、180°，Repeat the above tests three times for each operating condition and take the mean value.
6. Leakage detection
The pressure for leak detection is 0.75 times the operating pressure, which is read on the micromanometer.The leakage value is read once per minute by the flow meter (the accuracy of the flow meter is 0.5-1.0 grade), and read three times in total to take the average value.
7. The fire-resistant breathing valve for low temperature detection is installed on the test stand and placed in the low-temperature box. The temperature in the low-temperature box falls to 4-15 degrees Celsius. At the same time, the room temperature air with relative temperature not less than 70% is continuously input into the low-temperature box. The box is closed in
