Quote in 15 min·24/7 × 365AS9120:2025 · ISO 9001:2015 · FAA AC 00-56B

A Look at Mechanical Seals

Posted on James WolfAviation

Anyone who has used both packing and mechanical seals can speak to the benefits mechanical seals bring to your system. The main advantage of mechanical seals is the drastic reduction of leakage, which ultimately saves valuable time and money. Mechanical seals are devices that seal machines between rotating parts and stationary parts, such as shafts and housing, and are an integral component of a pump. Their primary job is to prevent the product being pumped from leaking into the environment. Two types of mechanical seals exist: single and double. In this blog, we will look at both types and their differences.

A single mechanical seal consists of two flat surfaces pressed together by a spring and slide against each other. Between the spring and slide is a fluid film created by the product being pumped. This film prevents the mechanical seal from contacting the stationary ring. The absence of this fluid would result in frictional heat that ultimately leads to the failure of the mechanical seal. Mechanical seals tend to leak vapor from the high pressure side to the low pressure side. This fluid lubricates the seal faces and absorbs heat from the associated friction, which crosses the seal as a liquid before vaporizing into the atmosphere. Therefore, it is common practice to use a single mechanical seal if the pumped product is not a threat to the environment.

A double mechanical seal consists of two seals arranged in a series. The inboard seal ensures the product is contained within the pump housing. The outboard seal prevents the flush liquid from leaking into the environment. Double mechanical seals are available in two configurations:

Back to Back: Two rotating seal rings are arranged facing away from each other and the lubricating film is generated by the barrier fluid. Mechanical seals of this type are commonly found in the chemical industry.

Face to Face: The rotary seals are arranged facing each other and slide in the opposite direction of one or two stationary seal parts. These are used throughout the food industry.

Any type of mechanical seal you choose will provide multiple benefits over conventional packing. For all types of mechanical seals and much more, look no further than ASAP Aviation Hub. Owned and operated by ASAP Semiconductor, we can help you find all types of parts for the aerospace, civil aviation, defense, electronics, industrial, and IT hardware markets. Our account managers are always available and ready to help you find all the parts and equipment you need, 24/7-365. For a quick & competitive quote, email us at sales@asapaviationhub.com or call us at 1-269-264-4495. Let us show you why we consider ourselves the future of purchasing.