20 mm 28mm 35 mm configurations | Upper and lower seal options

Luwint offers aftermarket mechanical seals for selected Flygt pumps fitted with Griploc seal arrangements. The range includes separate upper and lower assemblies, with Tungsten Carbide sealing faces and FKM (Viton) elastomers as listed in the supplied catalogue.

Selecting the correct replacement requires the pump’s complete identification, seal position and original configuration. A matching shaft diameter alone does not establish compatibility.

Understanding the Griploc Arrangement

Griploc is Flygt’s mechanical face-seal design incorporating a shaft-locking mechanism. In the original system, separate inner and outer seals perform different functions:

• Upper / inner seal: separates the seal-fluid chamber from the motor housing.

• Lower / outer seal: prevents the pumped liquid from entering the seal-fluid chamber.

These are separate seal assemblies, rather than a single integrated Plug-In seal unit. Confirm the arrangement fitted to the pump before ordering.

Catalogue Application References

Shaft size	Seal position	Catalogue code	Listed Flygt pump reference
20 mm	Upper	FT20-SGU	2075 / 2066 — Griploc configuration
20 mm	Lower	FT20-SGL	2075 / 2066 — Griploc configuration
35 mm	Upper	FT35-SMU	3127 — Griploc configuration
35 mm	Lower	Confirm when ordering*	3127 — Griploc configuration

The references above follow the supplied replacement catalogue. Check the pump version, original seal part number, mounting dimensions and drive arrangement before confirming suitability.

Listed Materials

For both the upper and lower assemblies, the catalogue specifies:

• Sealing faces: Tungsten Carbide against Tungsten Carbide — TC/TC.

• Elastomers: FKM, listed as Viton.

Confirm the exact carbide grade and elastomer specification for the application. Compatibility must cover both the pumped liquid and the seal-chamber fluid.

Operating pressure, temperature and speed limits should be confirmed for the replacement supplied; original Flygt ratings should not automatically be applied to aftermarket assemblies.

Selecting the Correct Replacement

Please provide:

• Complete pump model and serial number

• Original seal part number, where available

• Upper or lower seal position

• Shaft diameter and key installation dimensions

• Clear photographs of the old seal and its mounting arrangement

• Pumped liquid, temperature and solids content

For repairs involving both sealing positions, identify each assembly separately. Do not assume that the upper and lower seals use identical components simply because their shaft size and listed materials match.

Sydney Supply. Detailed Catalogue Available.

Contact Luwint for the full Flygt replacement mechanical seal catalogue, including additional sizes and configurations.

Send your pump details or old seal photographs for identification assistance. We can confirm available replacement options, pricing and dispatch timing for the required assembly.

Contact: Wayne Liao
Email: wayne@luwintonline.com
Mobile: 0433 986 633

LUWINT is an independent aftermarket supplier and is not affiliated with or endorsed by Flygt or Xylem. Griploc and Flygt names are used solely for identification and cross-reference.