What kind of valve is good for releasing acid from a sulfuric acid storage tank?
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How should the acid discharge port of a sulfuric acid storage tank be designed? What kind of valve is good?
Our company currently uses ball valves with an F4 lining; in the past we used 316L stainless steel ball valves, and both worked well. (Two-valve)
Local reinforcement near the acid discharge port; acid is discharged from the bottom; dual Mo2Ti stop valves, the first one is normally open (opens and closes once after some time), while the second one is used regularly.
It’s better to use stainless steel, with two valves – one normally open and one normally closed.
Enameled diaphragm valves are the first choice, fluorinated-plugged valves are the second choice, and ball valves are the last choice. Of course, dual valves are needed, with the first one acting as a safety valve that remains open at all times. Stainless steel is the preferred material for pipes in front of the valve, with thick-walled seamless pipes as a secondary option. The flange should be custom-made, made of stainless steel or thick carbon steel. There’s only a little material in this area, so it’s difficult to fix problems once they occur. Try to get it done right the first time, and don’t think about it for over a decade.
It is best to use stainless steel, one normally open and one normally closed
I don’t think it’s necessary to use stainless steel; a cast-iron stop valve will do just fine. It’s cheaper, and it won’t break even after 10 or 20 years. It can be used for both constant opening and constant closing purposes.
There is a significant difference in material between carbon steel storage tanks and stainless steel valves, which can easily lead to electrochemical corrosion. Polytetrafluoroethylene-lined valves are expensive, so cast iron valves are chosen instead.
We used stainless steel ball valves before, and they were quite good
We are also using stainless steel double valves now. The performance is quite good; it’s hardly ever broken (in four years). The estimate for cast iron is a bit uncertain.
When the economy permits, stainless steel is a better choice; it should have two valves, one normally open and one normally closed； Otherwise, use cast steel valves; it’s best to avoid cast iron ones
Enameled diaphragm valves, plug valves, and stainless steel ball valves are all suitable
Since the valve is normally open, it’s best not to use ball valves, as they don’t operate frequently and are prone to getting stuck; instead, use gate valves or check valves for isolation
We started with the PTFE ball valve, and found that it was difficult to move as it would get stuck; the gears were damaged as well. Of course, quality issues cannot be ruled out. The valve body of cast iron has previously broken. Later, it was replaced with three-eccentric butterfly valves, one domestic and one from Lewis; that works fine.