Reusing breather valves
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This post was last edited by henjuese on 2018-5-29 at 14:36. Dear colleagues: Our company has 3 small tanks that require the installation of vent valves. The set pressure for pressure relief is +100 mmH2O, and the set pressure for vacuum relief is -25 mmH2O. The required exhaust volume is 495 Nm3/h, while the required intake volume is 230 Nm3/h; calculations show that a 6” vent valve will suffice to meet these requirements. At present, in order to make use of existing assets, our company plans to reuse the vent valves from previous renovation projects. These valves are 10” in size, with a set pressure of +100 mmH2O for pressure relief and -25 mmH2O for vacuum relief – there’s no problem with that. However, the actual exhaust volume of a 10” vent valve is 2482 Nm3/h, and its actual intake volume is 1458 Nm3/h, which is quite different from those of a 6” vent valve. I would like to ask my colleagues: could there be any risks if we use 10” vent valves instead of 6” ones?
With the pressure set the same, there should be no problem with a larger breathing volume
I was wondering if the exhaust volume of this breathing valve is specified by the manufacturer. . .
The discharge volume is calculated in accordance with the API-2000 standard, based on the feed rate to the tank and the impact of ambient temperature on the tank’s discharge volume. The manufacturer uses this calculated discharge volume to select a breathing valve with the appropriate diameter and overpressure rating. I’m not sure if my explanation is clear... :)
Take a look at this magazine, and by combining it with API-2000, you’ll be able to learn how to do the calculations; it’s actually quite simple.
Oh, I calculated it based on sh3007. Thank you. . .
It has no impact; as long as you set the pressure to meet the requirements of your storage tanks. But this is rather wasteful and extravagant.