PS-Seal (Dustlip)

Composition and construction

Applications and why this type is so suitable

You typically choose a PS-SEAL (Dustlip) when you are dealing with external contamination such as dirt, dust, mud, or splash water on the outside, combined with heavier conditions such as higher pressure or vacuum, high shaft speeds, chemically aggressive or abrasive media, and a wide temperature range (guideline -90 °C to +260 °C). In such situations, the Dustlip helps keep contamination away from the main lip, which in practice keeps the seal stable for longer. Garlock also positions the PS-SEAL as an alternative to braided packings and in some cases even to mechanical seals (depending on the duty).

Materials (lip) and selection guide: strengths/weaknesses (shorter)

Garlock supplies multiple GYLON® (modified PTFE) lip materials to match the PS-SEAL (Dustlip) to the medium, hygiene requirements, and (dry) running conditions. GYLON® Black (graphite) is the standard choice for general industrial use, especially when there is sufficient lubrication and you want maximum all-round performance without food requirements. For food/pharma, you typically choose GYLON® White (food compliance, suitable for process media) or GYLON® Blue, which is especially known for higher flexibility and strong dry-running properties. For abrasive media, options include Brown-White (less sensitive to abrasion within a food context) and industrial compounds such as MS (focused on wear resistance in abrasive duty) and KF (a good balance for partially abrasive conditions, with decent dry-running performance). F Econol is often chosen when you place strong emphasis on dry running and/or vacuum applications.

Material Table

Comparison: Dustlip vs Back-to-Back, Reverse, Standard and Tandem

Within the PS-SEAL family, the differences mainly come down to lip configuration and the problem you want to solve. The Standard PS-SEAL is the “single-lip” version: compact and efficient for sealing in one direction when the environment is relatively clean. Dustlip adds an extra lip on the outside that is mainly intended to keep dirt, dust, and splash water away from the main lip; you choose this when the outside of the machine is “dirty” and you want to increase service life. The PS-SEAL Reverse is still a single lip, but installed in the opposite direction, and becomes especially relevant when you want the product side to be as “clean” and smooth as possible (for example, for hygienic design or to limit dead spaces). The Tandem PS-SEAL uses two lips in the same direction: this is intended to increase sealing security or distribute the load (for example, if you want just a bit more assurance against leakage without a true two-sided separation). The PS-SEAL Back-to-Back has two lips in opposite directions and is therefore the logical choice if you want to seal in both directions or if you want to separate the internal medium and the external environment with one unit (a more “double-sided” function than Dustlip).

How to select the right size and material (shorter)

Start with the size format d1 × d2 × B (shaft diameter, bore diameter, width/height) and work from there toward fit and surface finish. Follow the recommended tolerances for shaft and bore, and pay extra attention to shaft/counterface quality: with PTFE lips, roughness, runout, and machining marks make the difference between “good” and “just not quite.” Then select the lip material based on your operating conditions: for generally lubricated industrial service this is often GYLON® Black; for food/pharma applications you typically choose GYLON® White, GYLON® Blue, or F Econol; for (partial) dry running or vacuum duty GYLON® Blue and F Econol are common directions; and for abrasive duty you look at Brown-White, MS, or KF. Finally, verify that your pressure/speed combination fits within the intended duty, especially in heavier operating conditions.

In summary, Garlock PS-Seal Dustlip is a reliable and versatile sealing solution for rotating shafts. With its exceptional resistance to high pressure, extreme vacuum, chemical aggression, and wide temperature range, this seal ensures reliable performance in demanding applications. The use of Gylon as the sealing lip material further enhances the seal's capabilities, delivering effective sealing and increased uptime. Trust in Garlock's expertise and choose PS-Seal Dustlip for your shaft sealing needs.

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