1. Test preparation
The fire-resistance breathing valve is correctly installed on the test bench. The device should not leak, and the inner wall of the test tube should be flat and smooth.
The detection medium for the fire-resistance breathing valve opening pressure, ventilation volume and leakage volume is air, its pressure is 0.1Mpa, temperature is 20 ° C, relative humidity is 50%, density is 1.2kg / m3, if the air is not in this state, it should be The gas converted into this state. The detection medium of the flame arrest breathing valve body pressure is 5-35 ℃ water.
First check its leakage, then check its sensitivity and ventilation one by one.
4.Water pressure detection
The pressure of the fire resistance breathing valve for hydraulic pressure test is 0.2Mpa, and the pressure holding time is 10min.
Install the fire resistance breathing valve on the flange of the gas storage tank, adjust the valve to gradually increase or decrease the pressure in the gas storage tank, adjust the valve disk to open, and read it from the connected micromanometer. Take out the pressure value, read the value once every minute, and then turn the valve disc 90 ° and 180 ° respectively, repeat the above test, repeat each working condition three times, and take the average value.
6, leak detection
The leakage detection pressure is 0.75 times the operating pressure, which is read from the micromanometer. The leakage value is read from the flow meter (the accuracy of the flow meter is 0.5-1.0 level). Each measurement value is read once per minute, and read a total of three times, and the average is taken.
7. Low-temperature detection fire-resistance breathing valve Install the fire-resistance breathing valve on the test stand and put it in the low-temperature box. The temperature in the low-temperature box is reduced to 4-15 ° C. At the same time, the relative temperature input to the low-temperature box is not less than 70% The normal temperature air, before the valve disc is opened, reaches the inside of the breathing valve to close the box, and then the temperature in the low temperature box is reduced to -30 ° C. After 24 hours of constant temperature, connect one side of the test rack to the micromanometer and the other side The surge tank with normal temperature air is connected with aerodynamics. When the valve disc of the breathing valve is open, read the pressure value. repeat three times.
The breathing valve is maintained and maintained once a month and twice a month in winter. The method: first open the valve cover gently, take out the vacuum valve disc and pressure valve disc, check the valve disc and valve disc seal, valve disc guide and guide rod sleeve for oil and dirt, such as oil and dirt The objects should be cleaned, and then put back in place. Move up and down a few times to check whether the opening is flexible and reliable. If everything is OK, close the valve cover tightly. In the course of maintenance and repair, if any abnormal phenomenon such as scratches or abrasion is found on the valve disc, it should be replaced immediately so as to be resolved in time.