Exploring the Major Differences Between a Lip Seal and CinchSeal
It can be hard to understand what people are talking about when it comes to shaft seals. Not only are there quite of few kinds—O-rings, braided packing, mechanical face seals and so on—but it’s sometimes difficult to know which kind is under discussion. For example, lip seals have been called mechanical seals, which causes them to get confused with mechanical face seals. If you’re not an expert, it can get messy. But don’t worry, in this blog post we will discuss two kinds of shaft seals — the lip seal and CinchSeal.
What’s the difference between a rotary shaft lip seal and a CinchSeal?
Lip seals and CinchSeal have at least one thing in common. They serve the same purpose: preventing leakage and excluding contamination. However, there are important differences in the way these seals do their job and how well they do it.
Rotary lip seals maintain a thin layer of lubricant between the “lip” and the shaft. The hydrodynamic action created by the turning shaft causes a pump action that helps hold the seal.
Lip seals offer:
- Affordable pricing, so replacement is reasonably inexpensive but often need to be replaced
- Small size to save space and, consequently, equipment cost
On the negative side, lip seals:
- Are designed to “grab” the rotating shaft with comparatively small surface, allowing greater access for contaminants and an increased possibility of leakage
- Don’t hold high pressure particularly well, limiting their usefulness
- Tend to wear out relatively quickly, especially in harsher environments, and so lose much of their cost-saving benefit
- Are stationary and can damage rotating shafts
- Lack government certification for dairy and poultry processing
CinchSeal, on the other hand, represents a relatively new innovation designed to seal powder, slurries or bulk materials on process equipment. The principle shares some features with the lip seal but there are significant differences.
- A much larger surface for the shaft/seal interface than lip seals can provide, reducing the chance of contamination and leakage.
- Polished stainless steel-plated and PTFE rotor cups, reducing the chance of contamination and leakage
- Elastomer that spins with the shaft, eliminating shaft damage and driving two “rotor cups” that are compressed with optimum load against stationary faces to seal potential leak paths
- Purging with air (or, when necessary, silicone grease) to:
- Create pressure that pushes the rotor against the stator, closing the sliding interface and stopping material from migrating into or out of a screw conveyor
- Establish an air barrier to keep product out of the seal
- Reduce friction-generated heat by cooling the rotating seal faces, prolonging the seal’s life
- Boot-mounted rotor cups that allow the rotary assembly to float with the shaft and accept the 1/4” misalignment – common to bulk-handling equipment
- Design that inherently provides self-lubrication so the seals operate dry
- USDA certification in poultry and dairy, making them ideal for use in food-processing applications
CinchSeal: the better choice
Advances in technology favor CinchSeal for virtually any situation calling for rotary seals. Some CinchSeal benefits include:
- Cost savings as a result of eliminating material loss, greatly reducing maintenance costs, preventing bearing failure and shaft damage, and using less power
- Durability deriving from a design that allows for operation in some of the most challenging environments
- CinchSeal is certified by the USDA
When it comes time to deciding which rotary seal to select for any application, it’s important to remember that low price doesn’t always translate into higher value. Frequent repair and replacement quickly eat into savings. Knowing what factors can lead to seal damage in a particular application as well as in general will help determine the best rotary seal solution so consider all factors when choosing the best product for you.
Since 1994, CinchSeal has been a major manufacturer of rotary shaft seals for screw conveyors, ribbon blenders, and all kinds of bulk-handling equipment. CinchSeal products serve as replacements and major upgrades that make the need for machine replacement rotary much less likely.
If you would like a quote, contact us now. Quotes and drawings are guaranteed to be available in 24 hours and custom engineering usually takes 10 days.