What type of valve is used for hydrogen chloride gas?
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Slightly positive pressure boiler, used for isolation on acid production furnaces, DN100. Medium: hydrogen chloride gas; temperature: 200–400°; requires acid resistance as it is corrosive. The customer requested ceramic pneumatic ball valves, but found the price to be too high. Is there another valve that can be used as a replacement? For example: 304 hard-sealed ball valve, or 316L hard-sealed ball valve? Does anyone with experience in this area have any advice? Thank you!
The PTFE-lined version can withstand at most 180 degrees; the customer needs valves that can handle 200–400 degrees
Our special materials are more expensive, but they also have better performance
There’s no other choice; PTFE won’t work due to the high temperature, and 304, 316, and 316L grades also won’t suffice because of the chloride ions present. A ceramic valve is the best option.
Hastelloy & NCu28 – 2.5-1.5 (nickel-copper alloy); take a look and learn more about it
If money is no object, use Hastelloy; if cost is a concern, ordinary 316 series valves are sufficient for temperatures up to 400°C. Under normal conditions, when there is no water in the system and the temperature exceeds 200°C, chloride ions do not cause as severe corrosion of stainless steel as one might think. The main concern is corrosion that occurs when there are fluctuations in operation or when the temperature drops below 150°C during shutdowns. Recommendations: 1. Provide proper heat tracing. Use a softer, thinner tube as the steam pipeline, and wind it several times around the valve body (we also have hydrogen chloride in our system here; I used 12mm copper tubes). Electric heating can also be used. 2. It’s advisable to have spare valve bodies available, as once corrosion caused by hydrogen chloride occurs, there is no other solution except to replace the valve
Fluorinated plastic linings can only handle temperatures up to 180 degrees; it is not recommended to use them at such high temperatures.
Valves with HDPE linings can be used