Ferrics, Alums and Polymers Image

Ferrics, Alums and Polymers

Containing chemicals that react to their environment

Ferrics, alums and polymers are commonly used to treat water and wastewater. There are several reasons why these substances require specialized storage:

  • Separation, settling and coagulation are major issues with these chemicals – and those conditions can be compounded by temperature variations.

  • Settling and separation issues can lead to difficulty in pumping the chemicals.

  • The chemicals are often delivered at elevated temperatures, testing the expansion and contraction capabilities of a tank.

  • Ferrics create fumes that can defoliate surrounding trees and plants.

  • Polymers can act as an environmental stress-cracking agent.

By providing the right kind of storage for these chemicals, safety can be maintained – and the integrity of the product can be preserved.

Talk to a chemical storage tank expert

The Poly Processing System for Ferrics, Alums and Polymers

Several of Poly Processing’s features can make your storage system work for handling ferrics, alums and polymers. An IMFO® system is ideal for sludge control and ease of cleaning, since the tank drains at its true bottom. Heat pads and insulation can help keep the chemicals at the optimal temperature, greatly reducing the chance of separation and settling.

A mixing system can also be installed to keep the chemicals from separating – and a scrubber can help reduce the effects on foliage if you’re venting outdoors.

As for handling elevated temperatures – this is where the strength of the XLPE tank comes in. The crosslinked construction of these tanks allows for greater expansion and contraction, while maintaining structural integrity, lessening your risk for tank failure.

For additional information on storing ferrics, alums, and polymers, including recommended storage tanks and components, download our Ferrics, Alums & Polymers Guide below.  

download our Ferrics, Alums and Polymers Guide


Chemical Resin Type Specific Gravity Rating Fitting Material Gasket Material Bolt Material
Aluminum Sulfate XLPE 1.65 PVC EPDM 316SS
Ferric Chloride XLPE 1.65 PVC EPDM Titanium
Ferric Sulfate XLPE 1.65 PVC EPDM 316SS
Ferrous Chloride XLPE 1.9 PVC EPDM Titanium
Ferrous Sulfate XLPE 1.65 PVC EPDM Titanium
Polymers XLPE 1.35-1.9* PVC EPDM 316SS

*Based on type of polymer, amount of solids, etc., specific gravities can vary. Consult the specific MSDS for correct weight.


Tank Specifications

Tank options include: 

High-density crosslinked polyethylene (XLPE) construction for maximum strength

OR-1000™ antioxidant inner surface 

Integrally Molded Flanged Outlet (IMFO®) for complete drainage 

SAFE-Tank® design for "tank-within-a-tank" protection 

Recommended System Components

SAFE-Tank® Double Wall Tank System

SAFE-Tank® Double Wall Tank System

Secondary containment: SAFE-Tank® if concrete containment is not available.

Alternative: PPC secondary containment basin or other secondary containment suitable for chemical, of adequate size for use

IMFO® Fittings

IMFO® Fittings

Fittings: IMFO® eliminates the need for confined space entry.

PTFE Expansion Joint

PTFE Expansion Joint

Plumbing: Requires flexible connections to allow for lateral and vertical tank contraction and expansion, and to reduce vibration stress. 

SAFE-Surge® Manway Cover

SAFE-Surge® Manway Cover

Venting: SAFE-Surge® manway cover is recommended on pneumatically loaded systems to support tank longevity.

Technical Overview

IMFO® Vertical Flat Bottom of XLPE:

  • 230–13,650 gallons
  • Appropriate spg rating for chemical as shown in Chemical Resistance Chart

Non-IMFO® alternatives:

Standard Vertical Flat Bottom XLPE:

  • 30–13,650 gallons
  • Appropriate spg rating for chemical as shown in Chemical Resistance Chart


  • 55–8,700 gallons
  • Appropriate spg rating for chemical as shown in Chemical Resistance Chart
  • Spg ratings for secondary tanks ≥ 3,000 gallons may be equal to or 1 less spg than primary tank.
  • All other tank sizes must equal primary tank spg rating.

Alternative secondary containment: PPC secondary containment basin or other secondary containment suitable for ferrics, alums and polymers, of adequate size for use

Plumbing: Requires use of flexible connections with fittings on lower third of sidewall. See Fittings & Accessories for flexible connections options.

•Expansion joints must meet the following minimum requirements:

◦Axial Compression ≥ .67˝
◦Axial Extension ≥ 0.67˝
◦Lateral Deflection ≥ 0.51
◦Angular Deflection ≥ 14°
◦Torsional Rotation ≥ 4°

Venting: See Venting Chart

Foundation: PPC IMFO® tank pad or smooth concrete, asphalt or solid steel foundation designed to accommodate IMFO®, SAFE-Tank® or vertical tank

Temperature: Product should not exceed 100°F at delivery or during storage to maintain ASTM D1998 design parameters. Contact Customer Support if chemical is to exceed 100°F.

Lid: SAFE-Surge® manway cover for pneumatically loaded tanks; bolted manway cover for all other applications

Options: Restraint systems for wind and seismic, level gauges, ladders, heating pads, insulation, fume-tight manway cover, mixer mounts, OR-1000™ for NSF-61 certification and engineering stamp