Should a newly built tank with ventilation holes undergo a water filling test for its roof?
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Is it necessary to conduct a water filling test on the roof of a newly built tank with ventilation holes? Pressure tests, both positive and negative, should be carried out on the tank roof. Thank you.
Additional note: The ventilation holes are on the tank wall.
Fill the tank with water to a level 1 meter below the maximum designed liquid level, seal all openings, and then slowly fill it with water while increasing the pressure. When the pressure reaches 2 kPa, stop filling the tank. Apply soapy water to the outer surface of the welds on the top of the tank for inspection. After the test, immediately open the holes at the top of the tank to allow communication with the atmosphere, restore the pressure to normal levels, and then continue filling the tank to the maximum designed liquid level. Once the tank is at this level, seal all openings again and conduct a test by releasing water, gradually reducing the pressure. When the pressure reaches -1.5 kPa, inspect the top of the tank. After the test, immediately open the holes again to allow communication with the atmosphere and restore the pressure to normal levels
Please see the additional information on the 2nd floor; the tank walls have ventilation holes
New tank roofs with ventilation openings generally do not require a water filling test. If the structural design of the tank top includes ventilation holes, it is primarily intended to maintain gas balance during use, thereby preventing damage to the tank due to large pressure differences between the inside and outside. Generally, for this type of tank, pressure tests at positive and negative pressures are more suitable to evaluate its structural strength under pressure and its sealing performance, rather than water filling tests. The water filling test is primarily used on sealed or nearly sealed containers to check their sealing performance and structural strength. .
No, are your ventilation holes simply open openings without flanges? During pressure testing, it should be blocked with a blind flange
The ventilation holes are 700X300. Do you know what a ventilation window is?
Look at the end of the two diagrams, GB50128
The positive and negative pressure tests are also carried out through water filling tests; see 50128, 7.4.6 for details
1. It’s likely that the construction unit followed the wrong sequence of operations – the water filling test should have been carried out first before opening the air vents； 2. As required by 50128, it is possible to waive the tests for the strength, stability, and tightness of the tank top ； 3. The requirements for storage media are quite high; there is concern that the integrity of the tank roof may not be sufficient, leading to rainwater leaking into the tank. In my opinion, a vacuum chamber test should be conducted on the tank roof, and where such a test is not feasible, MT (or PT) testing should be used as a substitute to ensure the integrity of the tank roof.