Vault tank Design pressure Test pressure
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I’m currently working on a project to renovate a 5,000 cubic meter dome tank, and I’ve noticed that the design pressure for many of these dome tanks is set at 1960 Pa for positive pressure and 490 Pa for negative pressure. What is the basis for these values? Additionally, how should the positive and negative test pressures be selected?
The design pressure for atmospheric-pressure storage tanks is specified in GB50341, the Design Code for Vertical Cylindrical Welded Steel Oil Tanks; under normal design conditions, it is taken as -50 to 200 mm of water column, with 1 mm of water column equivalent to 9.8 Pa – thus 50 mm corresponds to -490 Pa, and 20 mm corresponds to 1960 Pa:$
Okay, thank you. I haven’t been able to find the specific terms. I would also like to ask how to determine the test pressure – should it be 1 times 1960, or 1.1 times 1960? :D
Just fill it with water to test for leaks, not using multiples of the design pressure. Take a look at GB50341, clause 3.01
The positive and negative design pressures are determined by the operating pressure of the breather valve installed on the tank. The test pressure and methods shall be carried out in accordance with A.5.1, B.6.1, and B.6.2 of GB/T50341-2014; the water filling test shall be conducted in accordance with the requirements of 7.4 of GB50128-2014.
-50–200 mm of water column; in our storage and transportation field, this pressure is generally used to determine the appropriate pressure for the safety manholes on floating roof tanks. I didn’t find this clause in the vault standards either. But we used to design according to this pressure. Why ask?
You can refer to the explanatory notes of GB50341-2003, Section 3 General Provisions, Table 1, Article 5