Unless you’re dealing with water, the solutions that are being sealed within systems are either acidic or basic. Either one can wreak havoc on a seal made of the wrong material type. For acidic solutions, a weak seal can cause a dangerous situation that can damage property and harm employees, this is where acid-resistant o-rings come into play.
Knowing what types of seals are best for these operations is imperative to protecting your assets and your employees. Not only are acids dangerous when touched, the fumes can often be just as harmful to both people and materials. Avoid making the mistake of choosing a material that is weak to acid. Here is a list of materials that can be used in operations involving acidic solutions:
Fluorocarbon Rubber
Fluorocarbon Rubber, or FKM, is best for applications requiring both chemical and heat resistance up to 400 degrees Fahrenheit, in addition to the acid resistant quality. There are even FDA grades available for food and beverage applications. A lot of food products are acidic, such as sodas, juices, and other fruit products.
Specialty fluorocarbons allow for a large range of resistances to various forces and chemical properties. If your application includes extremely acidic solutions, then these may be your best option. Customization is often a key concern for applications in the current industry trends as each operation has such unique and specific needs for their operation to run at the highest possible efficiency. Specialty materials allow for the most flexibility and can be designed by experts to fit your application.
EPDM
Ethylene Propylene Diene Monomer, or EPDM, is resistant to weathering, ozone, water, and steam, as well as the acid resistance needed for these operations. Compounds cured with peroxide have excellent compression set resistance. So, if you are looking for a material that can retain its shape under high levels of pressure and is resistant to most acids, EPDM may be the way to go. Often it’s a combination of harsh factors that destroy a seal, so knowing if it is acid-resistant is merely the first step. High-pressure operations aren’t uncommon, and when you need a compound that resists acid and deformation, EPDM should be considered.
Materials to Avoid
A lot of materials are able to handle lower acidity fairly well. However, there are certain materials that are very bad at handling acids and will degrade quickly under this kind of stress. Knowing these materials is just as important as knowing ones that are good for acid-resistance.
Silicone is an extremely common material for o-rings and is not good at resisting acids. While you may want to use silicone because of its low cost and good set resistance, it is a poor choice if the solutions you are sealing are acidic. Urethane is another material that should be avoided in operations using acids. Certain rubbers have a mild resistance to acids in static applications, but high acidity is very corrosive to most rubbers.
Selecting the Right Seal for Your Operation
Acidity is merely one factor that should be considered when choosing the right seal for your operation. Other factors in combination with acid can make the process of finding the right seal complicated and potentially dangerous and expensive.
When you are choosing the o-rings for your systems, consulting with an expert in the industry, and buying seals from a reliable manufacturer are essential to your success. Real Seal has been in the industry for decades, creating and finding solutions for a massive range of applications. Contact Real Seal today to ensure your company’s success!
