Sulfur Dioxide Cylinder Specifications
Sulfur dioxide cylinders are used items. Details must be available, similar to chlorine, with some senior members. I was thinking of extrapolating information.
I understand the issue about the storage tank. The installation where I saw this had a storage tank pressure of about 4 kg/cm². So far, the information I have been able to gather is as follows:
- 21.1 degrees centigrade: 237 kPa (2.37 kg/cm²)
- Liquefaction: 388 kPa (3.88 kg/cm²) at 32.2 degrees centigrade (56.3 psig)
Design Temperature and Pressure
The design temperature must consider typical ambient temperatures since this affects the vapor pressure of liquid SO₂. A typical maximum operating temperature is 50°C. The mechanical design temperature can be conservatively set at 100°C.
The design pressure must be set higher than the vapor pressure at the maximum operating temperature. A typical design pressure for a storage vessel is 1448 kPa(g) (210 psig). Relief valves should be set at 1379 kPa(g) (200 psig), which is 5% lower than the design pressure.
Materials of Construction
All materials should conform to ASME/ASTM standards. Typically, ASTM A516 Gr. 70 carbon steel will be used for all pressure-containing parts. When cold product or ambient temperatures are involved, all materials must be impact tested using Charpy 'V' notch specimens at -46°C (-50°F). No specimen must be less than 15 ft. lbs.
In addition to impact testing, all material shall be normalized.
Corrosion Allowance
Even though anhydrous liquid SO₂ is not corrosive to carbon steel, any moisture entering the tank when in contact with liquid SO₂ will be corrosive. A typical corrosion allowance will be 3 mm (1/8").
Based on this, I would like to know the shell thickness and dish end thickness.
Regards,
S.K. Deshpande
Kandivali East, Mumbai.