Standard ASME (HLW) Hot Water Storage Tanks
NSF Certification for Drinking Water System Components
HLW HOT WATER TANKS
- HLW ASME code, Section IV applies to commercial- and industrial-sized hot water storage tanks.
- The minimum nominal water capacity in these industrial and commercial hot water tanks is 120 gallons (450 Liters).
- The maximum temperature is 210℉ (99℃) and maximum pressure is 160 psig (1100 kPa) for these potable hot water tanks.
Commercial Hot Water Tanks’ Usage
- Vessels built under the HLW ASME code may be used for storage of potable water in several different industries where a large quantity is required.
- The following businesses could benefit from our hot water storage tanks: food processing, dairies, pharmaceutical, chemical processing, hospitality, commercial laundries, hospitals, multi-dwelling apartment buildings, and many other industries.
Potable Hot Water Tanks’ Sizes
- Hanson vertical standard sizes for potable hot water tanks are from 140 to 2150 gallons.
- The horizontal standard sizes for hot water storage tanks range from 180 to 3500 gallons, with an outside diameter ranging from 30 to 72 inches.
- The tanks are supported by angle legs or solar feet.
- The standard lined potable hot water tanks are built with an 11 x 15-inch handhole in order to access the inside of the tanks for the lining.
- This handhole is not required by the HLW ASME code. The minimum manway size is 12 x 16 inches.
- The smaller the tank surface, the heat loss is less, therefore the larger tank diameter is better.
Lining in Hot Water Storage Tanks

- Hanson tanks are lined with glass, cement, or epoxy.
- Hanson Tanks for drinking water system components are NSF Certified.
- A galvanized option is also available for commercial hot water tanks.
- The protection the lining offers is necessary on the steel surface because of a dissolved oxygen in the water works to corrode the tank and connections that can lead to leakage.