Maintaining the proper temperature of a chemical is often critical to safe storage. For example, sodium hydroxide at a 50% concentration will start to crystallize at or below temperatures of 60 degrees F. With polyethylene tanks, heating pads and insulation can maintain the specific temperature of the chemical you’re storing—even when your chemical tank is exposed to low air temperatures.
The Chemical Tank Heating System
Poly Processing’s chemical tank heating system is comprised of tank heating pads and a temperature controller, or thermostat. The quantity and size of the silicone heating pads depends on the size of the tank, the required chemical temperature, and ambient environmental conditions.
Tank heating systems can be built to a Delta T of 30, 60, and 100 degrees F. The temperature controller is a redundant system designed to prevent overages and overheating. The controller can also connect to a SCADA system or alarm to monitor the temperature of the chemical.
Insulation is applied to the tank to help maintain the temperature of the chemicals and to help prevent temperature change from environmental factors. The insulation is then covered in 2 coats of latex paint.
Frequently Asked Questions
Our customers often have questions about setting up a temperature control system for polyethylene chemical tanks. Here are the most common questions we hear. If you have other questions, our tank experts are always ready to provide personalized help.
What is the insulation R-value or measure of thermal resistance?
The tank insulation used in heating systems has an R-value of 6.3 per inch.
How thick is the insulation?
The insulation is 2 inches thick with an R-value of 12.6. Don’t forget to consider this addition to the tank diameter when determining the placement of your tank and any restraints or fittings that may be impacted.
How do you determine the correct delta T of a system?
First, determine the lowest ambient temperature that you could experience in the environment where the tank will be stored. Take the delta T number and subtract that lowest temperature.
If the result is higher than the delta T rating for the tank, then your tank is not adequate to handle the ambient temperature. You will need to move up to a higher delta T-rated system.
How do you determine wattage of the heating system?
To determine the wattage of the tank heating system, note the name and quantity of the heating pads. The heat pads we use can produce 210 watts or 420 watts depending on the application. You simply multiply the number of pads by the wattage to determine total heating wattage. Poly Processing has in house experts to help with calculations.
How do you determine the amperage draw of the heating system?
Unless a system has been modified, typically all systems are based on a 110- to 120-voltage supply. Amperage draw can be determined by dividing the total watts by the voltage supply.
For example: if your system has three 210 watt heating pads, multiply the watts per pad (210) by three pads for a 630-watt system. Then, divide the total wattage of the system by the 110-volt supply. This gives you a 5.73 amp system.
How do you handle your double-wall SAFE-Tank heat trace and insulation?We oversize the SAFE-Tank heater system by 40 percent, compared to our standard single-wall tanks. We factor the interstitial space between the primary and secondary tank into the calculation, as well.
When you order a polyethylene tank heating system on a SAFE-Tank, the pads and insulation are on the outer containment tank, not the primary tank. The heating system is increased in order to pass heat through the interstitial space.