Polypropylene Plastic Tanks FAQ
Q. What plastic tanks materials are best for large plastic tanks?
A. Homopolymers such as polypropylene and polyethylene are ideal for large
plastic tanks. Polyethylene roto mold tanks are very cost-effective for large plastic
tanks, too. Where large plastic tanks are used for special applications such as bright
dip or plating, fabricated polypropylene plastic tanks are recommended.
Q. Are plastic tanks the best choice as liquid storage tanks?
A. Plastic tanks are often advantageous as liquid storage tanks when aggressive
materials, such as acetone (dimethylketone) or diesel fuel, are involved.
Q. Which plastic tanks are recommended for extreme temperatures?
A. CPVC (chlorinated PVC) plastic tanks, and polypropylene plastic tanks are both
usable to 220°F. PTFE is a plastic tanks material usable to 400°F. Polypropylene
plastic tanks are not recommended for temperatures below freezing.
Q. Which plastic tanks are best for UV exposure?
A. White plastic tanks, or black plastic tanks made with UV-impregnated resins,
are highly UV-resistant, and are UV stabilized through the material.
Q. Are plastic tanks best for high or low ph?
A. Plastic tanks made of virgin polypropylene are suitable for extreme ph applications.
Q. What are the size limits on large plastic tanks?
Can plastic tanks be any shape?
A. Roto mold plastic tanks can be elliptical, rectangular, cylindrical -virtually any shape.
Restrictions on plastic tanks involve shipping. If plastic tanks have a weir (separator),
for instance, care must be taken when the plastic tanks are designed, in order to
prevent bowing during shipment.
Q. Are plastic tanks more chemical-resistant than stainless or alloy steel tanks?
A. Plastic tanks, specifically polypropylene plastic tanks, are compatible with alkaline
solutions, mineral oils, amines, jet fuel (JP3, 4, 5), and hydrogen peroxide, plus common
acids including hydrochloric (20%), maleic, nitric (50%) and phosphoric.
There are instances where plastic tanks are not appropriate, including concentrated acids,
benzene and toluene. For concentrated acids, Hastalloy is preferred. For benzene and toluene,
PVDF, a special plastic tanks resin, is often specified. PVDF plastic tanks are exceptionally
resistant to inorganic acid solutions.
Q. Are the requirements for food grade plastic tanks the same as
potable water tanks?
A. Natural unpigmented polypropylene plastic tanks are classified as food grade plastic
tanks, also potable water tanks. Other food grade plastic tanks are stainless steel or
Q. Can any liquid storage tank be used as a chemical tank or bulk storage tanks?
A. No – the material stored determines whether a particular tank material is appropriate.
Q. Are poly tanks, polypropylene tanks and plastic tanks all the same?
A. “Poly” can mean polypropylene or polyethylene. Plastic tanks is a category that
includes those, also PVDF, a plastic tanks material that’s resistant to halogens, acids
and radiation, and is the plastic tanks material of choice in the semiconductor
and pharmaceutical industries.
Plastic tanks also encompasses PTFE, a plastic tanks material with excellent thermal
and electrical insulation characteristics.
Q. Can fiberglass tanks be used as a liquid storage tank or chemical tank?
A. Tri-Mer’s fiberglass tanks made with polyester resins are suitable for use in liquid
storage tanks or chemical tank. Fiberglass tanks are resistant to acids, caustics and
high heat, also galvanic and aerobic corrosion and many chemicals. Fiberglass tanks
are very suitable for a petrochemical liquid storage tank.
As with all tanks, resins must be selected carefully. Like plastic tanks, fiberglass tanks
are not always suitable as a chemical tank. Fiberglass tanks can be attacked from
hydrolysis and oxidation, for example. Consult Tri-Mer regarding the best chemical
tank material for your application.
Q. How do fiberglass tanks differ from plastic tanks or poly tanks?
A. Fiberglass tanks are made differently from plastic tanks or poly tanks.
Polypropylene plastic tanks are homogeneous;. The homogeneity of polypropylene
plastic tanks protects against chemical attack if the plastic tanks are scratched or gouged.
Fiberglass tanks are laminated, and can de-laminate over time. If fiberglass tanks
are scratched or gouged, chemical attack can occur.
Q. Are there structural differences between fiberglass tanks and polypropylene plastic tanks?
A. Normal expansion and contraction can cause cracks within the layers of fiberglass
tanks, allowing wicking and chemical attack. Expansion/ contraction doesn’t adversely
affect polypropylene plastic tanks.
Also, repair (both internal and external) is easier with a polypropylene plastic tank
than with a fiberglass tank.
Q. Where appearance is important, are plastic tanks generally preferable
to fiberglass tanks?
A. Polypropylene plastic tanks provide a cosmetically cleaner appearance
than fiberglass tanks.
Q. Are polypropylene tanks the best choice for bulk storage tanks or
food grade plastic tanks?
A. Polypro is FDA-approved and prices for these plastic tanks are low.
Q. Are polypropylene plastic tanks most versatile?
A. Polypropylene plastic tanks are suitable for many applications.
Exceptions include strong oxidizing agents, and chlorinated or aromatic hydrocarbons.
Polypro plastic tanks are not suitable for these.
Q. How do polypropylene plastic tanks differ from FRP tanks?
A. Polypropylene is homogeneous and is not laminated, as is FRP. Also, if the tank
is damaged, polypropylene plastic tanks are easier to repair than FRP, regardless of
whether the damage is internal or external.
This information is for general information purposes only.
For specific applications, please consult Tri-Mer.
1400 Monroe Street
P.O. Box 730
Owosso, MI 48867; USA
Phone: (989) 723-7838
Fax: (989) 723-7844
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