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Chemical Resistance Chart


 


Select the Material and Chemical to be used and then click Submit.

  Material:
  Chemical:

For over forty years, Harrington Industrial Plastics, Inc. has been dedicated to the simple premise of providing our customers with a better way of handling corrosive liquids. This premise, together with our commitment to redefine customer service, built Harrington into the largest distributor of industrial plastic piping in the United States.

Over the years, we have constantly sought to provide new and better products as they become available and are consistent with our goal of selling the best at the most economical cost.

INTRODUCTION

Engineers must carefully select materials for vessels, piping, pumps and gaskets when designing systems for handling corrosive chemicals. With a relatively recent awareness of environmental issues, engineers’ jobs take on a new emphasis.

Designing a system for a specific application usually involves referring to several sources on piping, tanks, pumps and elastomer seals. Until the advent of synthetics, such as plastics, choices were limited to various grades of metal and alloys. Now the field is greatly expanded. In this Chemical Resistance guide, Harrington has provided a single resource of non-metallic and high-purity steel products based on manufacturers' recommendations and our own extensive experience. It is important to note that these tables should be used only as a guide. In all cases, a physical test of the material under actual operating conditions is the only way to ensure the success of a particular material for the application.

Engineers must take into account changes in internal and external temperatures and pressures, the affects of UV and mechanical stresses.

Corrosion is defined as a gradual wearing away. This is an accurate definition when dealing with metals. With non-metallic materials, such as plastics, there is no rate of corrosion; they are either resistant or they deteriorate completely from a chemical compatibility stand point. However, it must be remembered that mechanical stresses will limit the useful life of a piping system. In the case of poor chemical resistance, the failure of the piping system is hastened by mechanical stress.

Metals tend to form a passive film on the surface to resist corrosion. Rust is a chemical reaction that forms iron oxide on iron and steel. Stainless steel is frequently treated with dilute nitric acid to produce an oxide layer on the surface which makes the material more resistant to chemical attack. While this surface layer slows the corrosive degradation, metals still exhibit a penetration rate of the aggressive chemical. An A-rating for metals means that the rate of penetration is <2 mils per year. A B-rating means that the rate is <20 mils per year and with a C-rating, the rate can be estimated at <50 mils per year.

Metals are listed as:
A = Excellent
B = Good, minor effect
C = Fair, needs further test
X = Unsuitable


Higher temperatures generally hasten the corrosion reaction that results in material failure. In the tables provided here, temperatures shown are the maximum that can be used for the specified plastic in the particular chemical application. Plastics also have low temperature limitations at which they may be used successfully. These tables do not address this issue. Harrington welcomes your specific inquiries.

There are many variables that contribute to the successful use of a particular material, whether it is metal or plastic. There are many different plastic compounds and formulations. A material determined suitable for a specific chemical application does not mean that the compounds of that plastic from all manufacturers can be considered suitable. A dash means we lack sufficient data.

Polyethylene tanks that are manufactured with HDLPE (high density linear polyethylene) can handle applications to 130°F. Polyethylene tanks manufactured with XLPE (cross-linked polyethylene) can handle applications to 140°F. It is important to note that tanks designed according to ASTM D 1998 are designed based upon 73.4°F. Snyder Industries exceeds ASTM D 1998 by designing its tanks based upon 100°F (ambient conditions).

As per ASTM D 1998, applications that will exceed 73.4°F, (100°F for Snyder tanks), need to be designed based upon the specific chemical application. When designing tanks for applications above 100°F, the manufacturer needs to take into consideration the chemical, its concentration, and temperature. (per ASTM D 1998-97 section 6.1.2 - All tank hoop stress shall be derated for service above 23 degrees C/73.4°F).

To the best of our knowledge, the information contained in this publication is accurate. However, we do not assume any liability whatsoever for the accuracy or completeness of such information. Moreover, there is a need to reduce human exposure to many materials to the lowest physical limits in view of possible long-term adverse effects.
To the extent that any hazards have been mentioned in this publication, we neither suggest nor guarantee that such hazards are the only ones that exist. Final determination of suitability of any information or product for the use contemplated by any user, the manner of that use, and whether there is any infringement of patents, is the sole responsibility of the user. We recommend that anyone intending to rely on any recommendation, or use of any equipment, processing technique, or material mentioned in this publication verify that all applicable safety and health standards are met. We strongly recommend the users seek and adhere to manufacturers’ or suppliers’ current instructions for handling each material they use.

COMPRESSED AIR AND GAS

Plastic Piping Systems designed for corrosive and/or high purity liquid service are not recommended for Compressed Air or Gas applications.

There are a few specially designed thermoplastics piping systems that are suitable for selected Compress Air or Gas applications. Consult your local Harrington Office for recommendations.

USE OF THE CHEMICAL REFERENCE TABLE

The aggressive agents are classified alphabetically according to their most common designation. Further descriptions include trivial and common names as trade names.

If several concentrations are given for a particular material, the physical data, in general, relates to the pure product that is 100% concentration.

In listing the maximum use temperature for each plastic type in a given chemical, it can, in general, be assumed that the resistance will be no worse at lower temperature.

HOW TO SELECT THE CORRECT MATERIAL:

1. Locate the specific chemical in the guide.

2. Select the material with a maximum use temperature that matches or exceeds the need. The Harrington philosophy has always been to suggest the least costly material that will do the job.

3. Where a material or elastomer appears to be marginal compared to the requirements, place a call to our technical staff for additional recommendations.


EXAMPLES:

1. Methylene chloride: in the table PVDF, Halar, or PTFE are the only materials suitable. Carbon steel works well for chlorinated hydrocarbons of this sort, and that would be our choice unless there was another reason to justify the higher cost of PVDF, PTFE, or Halar.

2. Sodium hypochlorite, 15% at 100°F: PVC is good to 100°F and is the least expensive of the materials available, however, you must use 724 CPVC cement for this and caustic applications.

3. For nitric acid, 40% at ambient temperature: the tables recommend either CPVC or polypropylene at 73°F. In most cases, CPVC will be the economical choice. Note that PVDF is rated for higher temperature use.

Note: The ratings shown for carbon and ceramic pump seals are approximate.
Please contact your local Harrington service center for a recommendation on your specific application.

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