Petrol tank breather valve is a crucial device for ensuring pressure balance inside the petrol storage tank and preventing medium leaking or impurities intruding. Therefore, petrol tank breather valve testing is essential to ensure the safe operation of petrol storage tanks. Let me introduce breather valve test procedure.
1. Petrol Tank Breather Valve Working Principle
Petrol tank breather valve, officially known as Pressure vacuum relief valve, abbreviated as PVRV. It balances the pressure difference between the inside and outside of the petrol storage tank by controlling the exhalation and inhalation of gas inside the tank. When the tank’s internal pressure is higher than the set value, the exhalation valve disc of the breather valve opens to release excess pressure. And when the internal pressure of the tank is lower than the set value, the inhalation valve disc of the breathing valve opens to inhale external air to supplement pressure. This dynamic process can effectively prevent petrol storage tank deforming or rupturing due to overpressure or excessive negative pressure, while reducing medium evaporation loss.
Breather valve test bench is an essential equipment for testing and calibrating breather valves. Before testing, place your breather valve on the test station and clamp it tightly to ensure that there is no pressure leakage during the test.
2.Breather Valve Pressure Test
This test typically uses compressed air as the test medium. It aims to verify whether a breather valve opening pressure meets its set value under positive pressure conditions.The operating steps are as follows: select Pressure Test Mode on computer of PVRV test bench. Then gently rotate the Pressure Regulator to slowly inject compressed air into the breather valve. When you hear a click sound from the breather valve or see a sharp drop in the pressure curve on the computer, immediately stop adjusting the pressure regulator. At this point, the exhalation valve disc of the breather valve has been successfully opened, and the computer will automatically record the breather valve’s opening pressure value. The machine will automatically compare the measured value with the setting value to determine whether the positive pressure opening of the breather valve is qualified. Generally, if the deviation between the two values is within ±10%, the machine will determine the test result as qualified; otherwise, it is unqualified.
3.Breather Valve Vacuum Test
It is also known as breather valve negative pressure test. And Iits aims to verify whether a breather valve opening pressure meets the set value under negative pressure conditions. First of all, switch to Vacuum Test Mode on the machine’s computer, and the vacuum pump inside the machine will create a negative pressure environment by vacuuming breather valve. Then slowly rotate the Vacuum Regulator. When you hear a click sound from the breather valve or see a sharp rise in the pressure curve on the computer, stop adjusting the vacuum regulator immediately. At this moment, the inhalation valve disc of the breather valve has been successfully opened, and the computer will automatically record the breather valve’s opening pressure value. The machine will automatically compare the measured value with the setting value to determine whether the negative pressure opening of the breather valve is qualified. Normally, if the deviation between the two values is within ±10%, the machine will determine the test result as qualified; otherwise, it is unqualified.
4.Breather Valve Sealing Test
It is designed to verify the sealing performance of a breather valve under conditions when the opening pressure is not reached. Input the test pressure (usually 70% to 90% of breather valve’s set pressure) and pressure holding duration (usually not less than 5 minutes) on the computer. Then start the machine, it will detect the breather valve’s leakage rate through pressure drop method, and automatically determine test results. Generally speaking, if the leakage rate is less than 5%, it indicates that the sealing performance of the breather valve is qualified.
5.Breather Valve Flow Test
This is an additional test. It aims to assess the breather valve ‘s ventilation capacity whether meets the petrol storage tank pressure release requirements under extreme conditions. Test method: Establish a stable pressure difference at the breather valve’s inlet. Then PVRV test bench will measure the air flow rate through the breather valve per unit time under the set pressure conditions. If the measured flow rate is greater than the design flow rate, it is qualified.
To help you further understand the breather valve test procedure, we have recorded a breather valve testing video tutorial for you to watch.
Frequently Asked Questions
Why does your breather valve test bench test the breather valve from three different angles?
To reduce testing deviation, our PVRV test bench will test the same breather valve at three different angles: 0°, 90° and 180°. Furthermore, the machine will test each angle three times and averages all the measured values to further eliminate testing deviation.
How to test hydraulic safety valve and flame arrester on petrol storage tank?
Hydraulic safety valve, flame arrester and breather valve together form a complete set of petrol storage tank safety devices. Our PVRV test bench is also suitable to test hydraulic safety valve and test flame arrester.
