Not only do we handle all styles of seals and environmental controls, we can also repair, modify and even build what you need when standard products don’t do the job. We repair all brands in-house.

We have developed a very powerful root-cause failure analysis capability to identify what is really going on in your pumps. We “follow the evidence” like CSI. From legitimate and reliable analysis, we can identify the cause or causes of premature failure, recommend the solution and provide it without long lead times or ridiculous prices.

We just don't know of another company that can do so much for you in the murky world of mechanical seals. With our training programs, we can even make the murkiness go away.

The family of shaft seals known as mechanical seals is the most advanced type of seal used in the mixing industry. They can handle the highest pressures, maintain nearly leak-free operation, and require minimum maintenance if installed and operated properly. The downside is the higher initial cost (both for the seal and for the more complicated equipment required surrounding the seal) and the expertise needed to service the seals. Mechanical seals are increasing in popularity due to the growing environmental restrictions regarding any leakage from process tanks.

There are hundreds of mechanical seal designs, but they all are variations of a basic layout consisting of a collar mounted on the shaft which uses springs to push a ring (which also rotates with the shaft) against another ring that is held stationary. The rings rotate against each other riding on a thin layer of lubricant, and the springs hold them so tightly together that leakage through the seal is reduced to an immeasurable amount. The mating surfaces of the rings must be perfectly flat to seal properly, and are manufactured to tolerance measured “light- bands." The rings must also be extremely hard to endure the pressure and wear, so they are usually made up of ceramic, carbon, silicon carbide, tungsten carbide or similar materials. The stationary “seat” is held in place and maintains a static seal with the mounting housing using gaskets or o-rings. The rotating elements of the seal must attain a static seal with the shaft using o-rings, wedges or packing.

Mechanical Seal Types

Cartridge Seal


Mechanical seal types are shown with examples which have the mechanical seal premounted on a sleeve, including the gland, and fit directly over the shaft or shaft sleeve (available in single, double or tandem). The major benefit, of course, is no requirement for the usual seal setting measurements for their installation. Cartridge seals lower maintenance costs and reduce seal setting errors.

The Bellows Seal


The bellows seal is another mechanical seal type and does not have to move along the shaft or sleeve to maintain seal face contact. The main advantage is its ability to handle high and low temperature applications. It also does not require a secondary seal. A disadvantage of this style seal is that it’s thin bellows cross-sections must be upgraded for use in corrosive environments.

Pusher Seal


Incorporate secondary seals that move axially along a shaft or sleeve to maintain contact at the seal faces. This feature compensates for seal face wear and wobble due to misalignment. The pusher seals’ advantage is that it’s inexpensive and commercially available in a wide range of sizes and configurations. Its disadvantage is that it’s prone to secondary seal hang-up and fretting of the shaft or sleeve.

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