- Poly tanks are lower cost than stainless steel or fiberglass
- Lightweight - less than one-half the weight of steel
- Seamless construction for easy cleaning and leak proof service
- Exceptional Impact resistance
- Broad range of chemical resistance
- Better weatherability
- Available in a variety of resins
- Translucent when molded of natural resin for visible liquid level
- Virtually maintenance free
Poly tanks have a broad range of chemical resistance to both Agricultural and Industrial chemicals. For Industrial Chemicals refer to the Snyder Chemical Resistance Recommendation Chart on that site or contact the chemical supplier to see if their product is compatible with high density linear polyethylene (HDLPE) or cross-linked polyethylene (XLPE). If they cannot answer your question, call Snyder Industries and we will be happy to research it for you. Try to have as much information available as possible such as the temperature of the product, the percent concentration of product (Ex: Sodium Hypo chlorite, 15%) etc.
Snyder uses HDLPE (high density linear polyethylene) to manufacture our tank line. High density linear polyethylene has good structural rigidity and impact resistance. It is resistant to a broad range of chemicals including sulfuric acid, sodium hypo chlorite, and sodium hydroxide. We also offer, for specific applications XLPE (cross-linked polyethylene). Cross-link polyethylene has excellent structural rigidity and impact resistance. It is used as an alternative to HDLPE for storing surfactants or solvent-based chemicals, or for higher service temperatures.
General guidelines of material selection are not advisable. It is always best to provide the tank manufacturer with specific application details (chemical, concentration, specific gravity, temperature, dimensions, mechanical loading) so a proper tank design recommendation can be made by the factory and/or your Snyder distributor.
A tank with a specific gravity of 1.5 can hold a liquid up to 12.5 pounds per gallon at 100 degrees F. A tank with a specific gravity of 1.9 can hold a liquid up to 15.75 pounds per gallon at 73 degrees F. Please note that an increase in liquid temperature will substantially decrease the specific gravity rating. Also, certain chemicals have environmental stress cracking agents in them so higher specific gravity tanks are needed to compensate even though the weight of the chemical may be lower. Please refer to the Snyder Chemical Resistance Recommendation Chart or call Snyder Industries to determine which tank design is best suited for the chemical application.
Because Snyder tanks have a stratiform wall thickness (varies from top to bottom on a tank), wall thickness 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 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 rotomolding process. Lower grades of resins will require a thicker tank wall to compensate.
The resin used to manufacture our linear polyethylene tanks (HDLPE) meet specifications contained in FDA Regulations 21 CFR 177.1520, © 3.2 an so may be used as an article or component of articles intended for use in contact with food, subject to any limitations in the regulation. Cross-linked polyethylene (XLPE) tanks do not meet FDA regulations. The HDLPE resin that Snyder uses is also NSF 61 listed.
Linear polyethylene (HDLPE) storage tanks have a maximum storage temperature of 130 degrees F. Cross-linked polyethylene (XLPE) storage tanks have a maximum storage temperature of 140 degrees F. NOTE: The leading manufacturers in this industry design their tanks based upon 100 degrees F with ASTM D 1998 calling out 73 degrees F. It is important to contact the factory when your application will continuously be above 100 degrees (ambient). The tank can be designed specifically for your elevated temperature application.
We do not recommend storing petroleum products in our tanks because they will permeate (soften) the tank walls. Contact Snyder with your specific application. You will find that aromatic hydrocarbons and halogenated hydrocarbons will not be recommended for polyethylene.
Biodiesel is the name of a clean burning alternative fuel, produced from domestic, renewable resources. Biodiesel contains no petroleum, but it can be blended at any level with petroleum diesel fuel to create a biodiesel blend. Biodiesel or B100 (100%) refers to the pure fuel. Biodiesel blends or BXX refers to a fuel that is composed of a % of biodiesel blended into a conventional fuel (example B20 = 20% Biodiesel blended with 80% conventional fuel). Snyder has conducted chemical compatibility testing on B100. Our chemical compatibility testing showed that Snyder’s uniquely processed HDLPE and XLPE resins are compatible with B100. From our chemical compatibility testing, Sii recommends ONLY above ground 1.9 specific gravity Industrial (ASTM) designed tanks (600 psi hoop stress) for B100 applications. Snyder does not recommend below ground, agricultural or other non-ASTM designed tanks to be used in this application. Snyder’s warranty for biodiesel B100 applications is one year (1) against defects in material and workmanship. Snyder may offer additional warranty other than the one (1) year warranty stated above. In such cases these warranty statements will be in writing only from Snyder. Snyder’s chemical compatibility testing does not include any biodiesel blends so Snyder has no recommendation for biodiesel blends at this time.
No, our tanks cannot be pressurized. They are all designed to atmospheric pressure.
Tanks specifically designed for above ground use cannot be put underground because the weight of the ground around the tank can cause the wall to collapse. If you have an application for a below ground tank we do have a cistern and septic tank line available that is designed for below ground use.
Snyder warrants to the purchaser for any manufactured tank product proven to be defective in material or workmanship within 3 years from date of original invoice from factory. An extended tank warranty may be available as a purchased option for an additional 2-year period (total of 5 years) for some chemical applications. Snyder also offers chemical specific warranties for industrial vertical & double wall tanks for certain chemical applications including sulfuric acid, sodium hypochlorite and others. Contact Snyder on questions regarding warranty for your specific application. Snyder warrants to the purchaser for any manufactured Intermediate Bulk Container (IBC) or dry material handling product proven to be defective in material or workmanship within 2 years (for polyethylene) and 1 year (for steel) from date of original invoice from factory. Contact Snyder on questions regarding warranty for your specific application.
There are many variables that can have an effect on the life of a polyethylene tank. The type of material being stored in the tank, it's concentration, and temperature. The temperature of the application can be a factor, especially if the tank design is not based upon the temperature of the application. Some applications may permeate the polyethylene at elevated temperatures. Special considerations - some chemicals will have long term affects on the polyethylene and may require special considerations. As an example, sodium hypo chlorite will degrade from UV exposure and elevated temperature. As it degrades it can build up sediment in the bottom of the tank. If this sediment is periodically flushed from the tank it will extend the life of the tank. Installation and PIPING! - The number one reason for tank failures is due to improper installation. It is important to follow Snyder's "Guidelines for Use & Installation". Having flexible connections that compensate for the expansion and contraction of the tank will extend the life of the tank. Is the tank used indoors or outdoors? The amount of U.V. exposure will be based upon the time of exposure and the closeness of the installation to the sun (elevation). What part of the country are you in? Tanks used outdoors in states subjected to more intense sunshine will be more affected by the sun. UV rays will have a detrimental effect on the life span of all poly tanks. Storage or process - Is the tank a holding tank or a processing tank? A tank that is continuously cycled will see more stress then a tank that remains at one level or close to one level for extended periods of time. Tanks with excessive agitation may also be exposed to undo stress. Stationary tanks will also not see the stress of a tank that is being transported.
Freezing temperatures will not have an affect on a polyethylene tank, however, if there is liquid in the tank, make sure the freezing liquid has enough head room to expand. Snyder utilizes a test called "Low Temperature Impact Resistance". This is a test utilized by both the ARM (Association of Rotational Molders) and ASTM D 1998. Snyder has testing capabilities that exceed the requirements of ARM and ASTM D 1998. They call out -20 degrees F for the test, but Snyder has conducted testing at -40 degrees F. This test is critical to determine if the resin has been properly processed and it will give you an idea as to the temperatures that the resins can see. It is important that efforts be made to avoid impacting the tank, especially with sharp items, at any temperature.
Snyder tanks are produced with a molded-in serial number (wheel-date/month format). In addition, the tank's bar code label has a 10-digit serial number and date of manufacture. Your Snyder Sales or Customer Service person, can help you interpret the date of manufacture.