Open top, rectangular tanks are used for processing in the metal finishing industry. MJCronin is right re cylindrical being cheaper for storage, but sometimes limited floor space matters.
I don’t see the need for expensive references. I have used
Design of Welded Structures, section 6.5 (cited by arto) for tanks up to 6.5 ft deep containing hot electropolishing acidic solution of SG 1.68. Made a tank like Figure 4, p. 6.5-5, except used a 2nd horizontal stiffener and threw in some verticals to handle about 2600 pounds of workload on the top flange.
To reinforce an old anodizing tank with a corroded steel frame inside fiberglass, I fabbed a girth rib of steel angle, bolted at the corners, with flats against the outer fiberglass wall, calculated similar to Figure 4.
For seismic considerations, just factor the maximum lateral acceleration into the SG of the liquid, e.g., if 0.2 G, multiply the liquid’s SG by 1.20 in your design.
[Note: presuming flat bottomed tanks, not up on legs]
Of course, all inside welds must be continuous, there are proper designs for inlets & outlets, etc. I suggest you read
Electroplating Engineering Handbook, 4th Edn., or the article “Chemical-Resistant Tanks and Linings” at
for more design considerations.
One additional comment: If working with stainless steel, it is usually cheaper to bend shapes from sheet rather than buying angle or channel. You can also buy oversized sheet and do some bending to minimize welding. On the 6.5 ft deep tank mentioned above, the top flange and lip were were from same sheet as the wall and a portion of the floor.
