Surge Tanks/Balance Tanks

A swimming pool surge tank capacity is defined as the volume of the portion of the tank that is above the centerline of the main drain line. Surge capacity is usually dictated by health department codes. One gallon per square foot of pool surface area is a common requirement.

Swimming Pool Balance or Collector tank are terms used to describe smaller tanks that accept water from the main drain and gutter lines with an exit connection to the pump suction. Swimming pool balance tanks are usually not big enough to meet any surge capacity code requirement.

Until the advent of fiberglass swimming pool surge or balance tanks these tanks were made of plain carbon steel, which is easily corroded by the intense chlorine rich fumes in the top of the tank, above the operating water level. Corrosive failure occurred at the normal water level in the tank.

Currently, the preponderance of these tanks is that they are constructed of fiberglass which is not damaged by the chlorine fumes. When using fiberglass there are construction considerations that differ from metal, mainly due to the fact that fiberglass is not as strong under vacuum. Several conditions can occur in the normal swimming pool operation which can create a vacuum in the tank:

1) Small-steel tanks are usually supplied with a 2” (too small) vent whereas fiberglass vents are much larger.

2) Rapid pump out-if the pump pulls more water out than can be supplied by gravity flow into the tank, an immediate vacuum will be created.

Mer-Made Filter reviews all surge tank inquiries with respect to possible vacuum creation and advises the customer if any design changes are required. 

Custom sizes and custom piping configurations are available in either cylindrical or rectangular shapes.