Water Tanks – Poly, Steel, and Portable Open Top tanks and Accessories

POLY Tank FAQs (Frequently Asked Questions):

The premium weight tanks and black or dark green vertical water storage tanks carry a three-year warranty from date of manufacture. Should a defect appear within the warranty period, manufacturer will supply a new, equivalent tank in replacement thereof. Manufacturer’s liability is limited to the value of the tank itself and specifically excludes the cost of installation and/or removal or consequential damages

Manufacturer uses a linear, high-density polyethylene resin that provides outstanding environmental stress crack resistance. The resin is UV stabilized but by keeping the tank sheltered or indoors you will prolong the life of your tank. 

Yes, it is safe to store water in the Manufacturer above ground tanks and below ground cistern tanks shown on our website. The resin used to manufacture these tanks meets FDA specifications for safe storage of potable water. 

Wall thickness varies from top to bottom on a tank, it is not the best gauge for determining the quality of a tank. The very bottom of the tank is the thinnest part of the tank and is made that way to flex when the tank is empty or full. The wall becomes thicker as you go from the top to the bottom of a vertical tank. This is done to increase resistance to head pressure created by the height of the liquid in the tank. The radius of the tank is thicker to increase strength where it is most critical. The actual weight of the tank is also not a good comparison when shopping for tanks. Just because a competitor may use more material in the tank does not make it a better tank. That is determined by the resin, mold design and the steps taken during the roto-molding process. 

Polyethylene storage tanks have a maximum storage temperature of 120 degrees F. Contents with a temperature greater than 120 degrees F – even for a short period of time – can weaken the tank’s structural integrity and make it susceptible to deformation and failure. 

The tank itself does not have a minimum temperature rating. If you plan to keep the liquid in the tank and you know that it will freeze, make sure that you leave room for expansion. The most likely part to crack on the tank is the bulkhead fitting which can be easily replaced. 

There is no good way to determine the life span of a polyethylene tank. UV rays will have a detrimental effect on the life span of any poly tank. Tanks used outdoors in California or Arizona are subjected to more intense sunshine than in Idaho, for example. UV rays and heat leach components from the resin and cause it to become brittle over time. Useful life of the tank can be extending through these actions: 

• Construct a cover for the tank to shield it from the sun.

• Paint the tank’s exterior to slow down the effect of the sun.

If a tank is beginning to show its age, you will be able to see fine fissures or hairline cracks referred to as crazing. Look for crazing on the dome of a vertical tank in the area where sunlight is most intense. These fine cracks will become more intense and visible as time goes on and will become stress cracks. Giving the tank a good hit with a baseball bat is as good a test as any. The resilience of a good tank will be obvious. A tank beyond its life expectancy will sound dull when struck and could crack as a result. It is better to check early and be safe. When a tank is determined to be unsafe or you know it is getting old, it is best to make it a non-drinking water only tank.

Flexible connections should be used between the tank fitting and the pump to allow for expansion and contraction of the tank as it is filled and as liquid is withdrawn. A good quality flexible hose is best. We also recommend proper support under heavy valves and fittings that may be attached to the tank fitting. Please refer to the warning labels on our tanks for details. These plumbing recommendations will also extend the life of the tank by reducing stress on the tank.