We take a closer look at the useful life of a chemical storage tank and what a warranty really means to the customer.
For more than 40 years, Poly Processing Company has helped customers solve problems associated with storing hazardous chemicals.
We have specialized in providing hazardous chemical storage tank solutions to the industrial, water, and wastewater markets. While we manufacture both crosslinked and linear polyethylene storage tanks, in hazardous chemical environments, crosslinked polyethylene is the material of choice.
Our customers report that crosslinked polyethylene tanks provide 15 to 20+ years of service in many applications. However, there are several factors and variables that have an effect on the useful life of any chemical storage tank, including the polyethylene used in the tank design.
The Effects of Chemical, Concentration and Temperature on Tank Life
The chemical, its weight and concentration, and operating temperature are all factors influencing the life expectancy of a polyethylene tank. For example, high concentrations of sulfuric acid are considered stress cracking agents and are more aggressive oxidizers than less concentrated chemicals such as 25-percent caustic soda. To protect from these sorts of chemical attacks, PPC offers several solutions including the OR-1000™ Anti-Oxidant System.
Another example is concentrated sodium hypochlorite (12-15 percent), which degrades from UV exposure and elevated temperatures. As it degrades, sediments that build in the bottom of the tank can cause more oxidation in the bottom section of the tank and can lead to a shorter tank life. To eliminate this sludge buildup, PPC offers the IMFO® (Integrally Molded Flanged Outlet). The IMFO® design promotes continuous “system” flushing, increasing tank life and operating efficiencies and giving the user 10-plus years of uninterrupted service despite harsh chemical conditions. Poly Processing chemical storage tanks are constructed from engineered materials and designed specifically for the chemical, concentration, and temperature requirements.
How Your Warranty Affects Your Chemical Storage Tank Purchase
One other important factor in purchasing the right tank is a manufacturer's warranty. Many manufacturers will publish a warranty or even offer or sell an extended warranty to help sell their product with the expectation that the tank will last through that period before anything happens. Poly Processing offers a five-year warranty for tanks in most chemical applications.
The reality for the customer when it comes to any warranty is how well a manufacturer supports its product and what the product’s actual useful life is beyond that period of time. PPC is the industry leader in the useful life of a tank and on average sees that XLPE tanks last three times longer than linear polyethylene tanks in the same application.
Installation and Piping Play a Role in Tank Life Expectancy
One of the single biggest reasons for tank life reduction is improper tank installation and “hard” piping. Polyethylene’s broad spectrum of chemical resistance versus other materials of construction is based on its ability to expand and contract. Flexible connections compensate for tank expansion and contraction, promoting a longer tank life. It is important to follow our Installation Manual Instructions during the installation process to set yourself up for many years of uninterrupted service.
Venting and Tank Life
Often overlooked, proper venting is a critical component that promotes tank longevity. Polyethylene tanks are rated at atmospheric pressure/vacuum. Adequate vent size is always based on flow and delivery rates so it is important to gather the following information to determine the proper venting requirements:
- Will the tank be filled pneumatically?
- Will the tank be vented to atmosphere?
- Does the length of the vent exceed three feet (piped to a central vent system)?
- Is a fume scrubbing system going to be used?
- Are vent screens going to be used that restrict flow?
- Does the tank manufacturer offer a method of “emergency venting” to prevent overpressurization?
Please check out our venting page for more information on safe and proper venting design.
Other items that affect tank longevity:
- Continuous cycling (fill/discharge)
- Excessive agitation
- Mobile applications
Poly Processing prides itself on having a top of the line field service team with more than 50 years combined experience. Should an issue arise under warranty or after the warranty has passed, we are equipped to service your tank needs with tank inspections and tank repair.
Poly Processing’s goal is to engineer a chemical storage system that meets the expectations of the end user and delivers a peace of mind knowing that it is built right for the intended use.