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Seal selection: In summary

“A bearing’s best friend is a properly selected seal!”

Combining SKF’s extensive industrial and technical experience, we continue to support customers’ decision-making when it comes to rotary sealing solutions. And, in the same way that SKF provides eight steps to choosing a suitable rolling bearing, this article summarizes a structured approach to seal selection.

For over a year, the Industrial Seals Expert has shared invaluable advice for seal selection. Breaking down basic functional aspects, such as grease retention, contaminant exclusion, and liquid separation capabilities, we provided an environment for operators’ sound decision making – based on the same methods SKF uses to choose seals for its own customers.

In part two of the Seal Selection series, we introduced SKF’s Machined Seals Concept (MSC) and discussed the plethora of opportunities that bespoke, made-to-order sealing solutions can provide. Parts three and four were particularly useful in aiding seal selection for different industrial applications.

If you haven’t had the chance to explore our various Seal Selection guides, you can begin with part one here.

From application to selection

Our approach is condensed into four key pillars, which were recently highlighted in an SKF-led webinar: application, requirements, other, and selection.

Let us break them down for you:

1. Understanding the application is the first consideration. This relates to all technical aspects, such as seal type and extent of movement. Pressurization, operating temperatures and heat balance, geometrical and countersurface qualities, and type of fluid media involved all need to be considered at this early, critical stage.

Key considerations:

Seal type: Contact seal, non-contact seal, or static seal?
Shaft arrangement: Horizontal or vertical?
Primary purpose: Retain lubrication and/or exclude contaminants?
Lubricant: Oil or grease?
Contaminant type: Particles, fluid, or both?
Counterface hardness
Circumferential speed at sealing lip

2. Requirements refers to the seal’s service life – from installation to decommission. At this stage, a seal’s integrity against leakage, loss of friction in operation, and other ageing factors, such as wear and deformation must be taken into account.

Key considerations:

Required operating time
Installation: Single or multiple installations?
Arrangement requirements: Blind installation? Spatial limitations?
Seal friction: Resulting temperature change? Leak tightness?
Potential shaft misalignment or deflection?
Run-out and concentricity?
Maintenance requirements

3. Factors which fall under the other category are generally extrinsic factors. The amount of seals required, availability, cost, and standards conformity should be factored in. These “immeasurable” factors can influence the manufacturing process and, in turn, the overall seal design, for example if large quantities are required and the shortest possible lead time is necessary.

Key considerations:

Purpose of request: Improve sealing quality? Better availability? Cost issues?
Industry requirements: Relevant standards conformity?

4. During the final selection stage, SKF analyzes the most appropriate approach to satisfy customer or distributor needs. Once the desired seals are received, it can then be installed and put into action!

Seal of excellence

That’s our Seal Selection series all wrapped up. Be sure to refer to our guides when looking to renew or upgrade your sealing solutions for new or legacy equipment. And remember: Industrial Seals Expert continues to deliver engineering advice, tools and guides, and other tips and tricks relating to industrial seals – so be sure to subscribe to ensure you are the first to know when new content is published!

Related articles

Tools & Guides
Seal selection – part 1
Find the right seal for different operating conditions
Tools & Guides
Seal selection – part 2
Choosing bespoke, machined sealing solutions
Tools & Guides
Seal selection – part 3
Shaft seals for general industrial applications
Tools & Guides
Seal selection – part 4
Choosing shaft seals for heavy industrial applications