When you have a joint between two surfaces, you need a seal. Think of the rubber gasket in a hose. When you screw the hose down onto your faucet, you pinch the rubber gasket, and it creates a seal that will prevent water from leaking around the threads. Similarly, you need seals for the joints in a compressor and other pieces of industrial machinery. Because of the high-pressure conditions present in industrial compressors and equipment, you need a seal that can hold up to the abuse. Aluminum makes a great choice of material for making a seal for at least four reasons. 

Corrosion Resistance

Aluminum will not rust away to nothing like iron will. Instead, when exposed to an agent that promotes corrosion, the top surface of aluminum corrodes and creates aluminum oxide. This layer will prevent further corrosion, which means you can use aluminum as a seal in applications where other metals would corrode away. 

Cold-Induced Brittleness

If your seal will be exposed to cold temperatures, you need to consider what effect the cold will have. Most metals will become brittle and prone to breaking when exposed to cold temperatures. This is not true of aluminum. Instead, it actually becomes stronger at colder temperatures. This is one of the reasons that aluminum is a popular material for use in the aerospace industry where extremely cold temperatures are common.

Non-Magnetic

When exposed to a magnetic field, many metals will become magnetized. This can interfere with the proper functioning of the equipment. Because aluminum is non-magnetic, it is ideal for use in areas where a magnetic field could interfere with delicate instruments. 

Malleability

Aluminum is more malleable and elastic than steel. If you are making a simple circular seal, malleability might not be much of a factor, but as you need more complex seal structures, malleability becomes an important factor. You can mold and spin aluminum to make shapes that simply would not be possible with a piece of steel. Also, aluminum is one of the lighter metals, so if the weight of your equipment is a factor, using aluminum will not significantly increase the weight of the equipment.

Because of the unique properties that aluminum possesses, it is an ideal material to use in making seals. If you need a replacement seal for a piece of equipment, you should request an aluminum seal unless the manufacturer requires a different metal. If you are designing a new piece of machinery, you should work with a company that makes custom seals to make a quality aluminum seal.