Question: What is the most common mechanical Seal?
The most common type of mechanical seal used in various industries is the single mechanical seal. Single mechanical seals are widely employed in pumps, mixers, and other rotating equipment to prevent leakage of fluids (such as water, oil, or chemicals) between the rotating shaft and the stationary housing.
The single mechanical seal consists of two main components: a rotating seal face that attaches to the shaft and a stationary seal face that mounts to the equipment housing. These faces come into contact with each other, creating a barrier to prevent the escape of fluids.
When Is a Single Seal Not Enough?
While single mechanical seals are the most common, they are not always the best choice.
You may need a more advanced solution such as a double mechanical seal when:
- Handling hazardous or toxic fluids
- Dealing with high pressure or temperature
- Preventing emissions is critical
- Running with poor lubrication or solids
Double seals introduce a second set of faces and a barrier fluid, providing added protection and containment. [arthomson.com]
Common Variations You’ll See
Within the category of single mechanical seals, there are several popular designs:
- Component seals (traditional, flexible and widely used)
- Cartridge seals (pre assembled for easy installation)
- Elastomer bellows seals like the common Type 21 (general service workhorse) [arthomson.com]
These variations all build on the same basic principle but are tailored for different levels of convenience and performance.