Aftermarket replacement for Grundfos double cartridge seal arrangements | 22 mm and 32 mm shaft sizes

The GFD range is a pre-assembled double cartridge mechanical seal intended for Grundfos pumps that use a double-seal arrangement (back-to-back or tandem) inside a dedicated seal chamber. It is selected where the pumped liquid must not reach the atmosphere, or where the process liquid would damage a single seal face through abrasion, crystallisation, hardening or high temperature.

The unit is supplied as a compact cartridge so the seal faces are protected during handling and installation. Barrier or quench fluid connections are required; the fluid keeps the faces lubricated and, in a back-to-back arrangement, maintains a pressure higher than the pump pressure so any leakage is inward.

Why Choose the GFD Range

• Cartridge construction reduces installation time and protects the seal faces until the unit is seated.

• Double-seal layout supports barrier-fluid systems for duties where zero external leakage is required.

• Available for the two shaft sizes commonly specified on Grundfos double-cartridge applications (22 mm and 32 mm).

• Face and elastomer combinations can be selected to match the liquid, temperature and barrier-fluid chemistry.

Choosing the Correct Model

Confirm the shaft diameter (22 mm or 32 mm), the seal arrangement on the pump (back-to-back or tandem), and the exact pump model before ordering. Dimensions, seat geometry and connection details must match the existing seal chamber and barrier-fluid piping. Photos of the nameplate and the installed seal, plus key chamber measurements, are the most reliable way to verify fit.

Typical Operating Conditions

Parameter	Range
Shaft diameter	22 mm, 32 mm
Pressure (seal chamber)	Up to 25 bar (barrier fluid must be controlled relative to pump pressure)
Sliding speed	Up to 10–15 m/s (depending on size and materials)
Temperature	Dependent on elastomer (EPDM typically to ~120 °C; FKM lower continuous rating; higher only with suitable face materials)

These figures are indicative range values drawn from typical double-cartridge and Grundfos double-seal documentation. They do not apply simultaneously to every material combination or duty. Actual limits are set by the face materials, elastomers, barrier fluid and the specific pump arrangement. Always confirm the barrier-fluid pressure requirements for the chosen arrangement (back-to-back requires barrier pressure above pump pressure; tandem uses lower-pressure quench).

Common Cross-References

Luwint	Principal OEM reference
GFD	Grundfos double cartridge seal arrangements (back-to-back / tandem) used on selected CR, CRI, CRN and NKG pumps

Cross-reference is by seal family and shaft size only. Dimension, seat and material matching is required before use. LUWINT supplies aftermarket replacements; these are not OEM parts.

Where It Is Used in Australia

• Industrial process and chemical duties on Grundfos CR-series multistage pumps fitted with double-seal chambers.

• End-suction pumps (including selected NKG variants) handling abrasive, viscous, crystallising or hazardous liquids.

• Applications where a barrier-fluid system is already installed and a cartridge-style double seal is specified for easier service.

Pump-model compatibility must be verified against the actual seal chamber and arrangement; a matching shaft diameter alone does not confirm fit.

Materials Available

• Seal faces: silicon carbide / silicon carbide, carbon / silicon carbide, or tungsten carbide combinations (selected according to abrasion and chemical resistance needs).

• Elastomers: EPDM or FKM (Viton). EPDM is generally preferred for water-based and alkaline fluids; FKM for many oils and solvents. Other compounds on request where the liquid requires them.

• Metal parts: stainless steel.

Material selection must match both the pumped liquid and the barrier/quench fluid. Supply the liquid name, concentration, temperature and pressure so the appropriate combination can be confirmed.

Sydney Supply. Help with Selection.

Current stock and lead times vary by size and material. Please contact us to confirm availability, pricing and dispatch timing for the specific GFD variant you need.

To select the correct seal, send:

• Pump model and nameplate photo

• Shaft diameter and any existing seal markings

• Clear photos of the installed seal and chamber

• Liquid, temperature, pressure and barrier-fluid details

• Whether the arrangement is back-to-back or tandem

Contact and Catalogue Request

Wayne Liao
Email: wayne@luwintonline.com
Australian mobile: 0433 986 633

Ask for the dimensional drawing or catalogue page for the GFD range when you enquire. We can also help identify an existing seal from photos if the model is not clear.

LUWINT supplies aftermarket replacement products for original equipment applications. We are an independent supplier and are not affiliated with or endorsed by Grundfos. Brand names and model references are used solely for identification and cross-reference.