Key Features

• H-Type Replacement: A fully assembled cartridge unit designed to replace the standard "H-Type" seals (HQQE, HQQV) found in Grundfos CR, CRI, and CRN vertical multistage pumps.

• Elastomer Sleeve Drive: Utilizes a robust rubber bellows/sleeve inside the cartridge to grip the shaft, transmitting torque without damaging the shaft surface.

• Speed & Simplicity: The cartridge design allows for seal replacement in under 20 minutes without completely disassembling the pump motor in many models.

• Shaft Protection: The internal rubber sleeve acts as a protective barrier between the metal drive components and the pump shaft, completely eliminating fretting corrosion.

• Balanced Geometry: The grundfos pump mechanical seal faces are hydraulically balanced to handle the high pressures (up to 25 bar) typical of multistage booster systems without overheating.

Workshop

This workshop is equipped with professional processing equipment and integrated with standardized material warehousing management, enabling a one-stop production process from precision machining of grundfos pump mechanical seal components to finished product delivery. Dedicated production lines for each grundfos pump mechanical seal model ensure part machining accuracy and production efficiency, meeting various high-specification manufacturing requirements for HVAC circulation, domestic water supply and building booster applications.

Product Research, Development and Testing

Our Product R&D and Testing focuses on optimizing seal performance through advanced simulation and material analysis. All grundfos pump mechanical seals undergo rigorous trials, including thermal cycling and pressure tests, to ensure durability, minimal leakage, and long service life in demanding industrial environments.

Industry Solutions

FAQs

Q: Is this compatible with the new Grundfos E-pumps?

A: Yes, the seal chamber dimensions for CR/CRI/CRN pumps have remained consistent. Our cartridge fits both standard and E-pump (smart pump) variants of the same shaft size.

Q: Which Grundfos pump models and shaft sizes do rubber cartridge mechanical seals fit?

A: Our rubber cartridge Grundfos pump mechanical seals are drop-in OEM-interchangeable replacements for CR, CRI, CRN multistage boosters, TP/NB/NK end-suction circulators and the H-Type HQQE/HQQV seal housings. They cover standard shaft diameters of 12 mm, 16 mm and 22 mm with no adapter sleeve required—direct swap without motor teardown or spring preload adjustment.

Q: What does the "rubber" part actually do inside a Grundfos cartridge seal?

A: The internal EPDM or NBR rubber sleeve (or O-ring pusher stack) acts as both a secondary seal and a shaft barrier. It eliminates metal-to-shaft contact, preventing fretting corrosion on stainless shafts, absorbs minor radial runout and thermal expansion, and provides the hydraulic balance force that keeps the carbon face loaded against the ceramic/tungsten seat across pressure swings.

Q: Can these rubber cartridge seals handle potable water and hot HVAC loops?

A: Yes. With EPDM secondary rubber rated to 120°C and WRAS/potable-water compliant face materials (carbon graphite vs alumina ceramic or tungsten carbide), they serve domestic drinking water, chilled water and low-pressure hot water loops up to 1.2 MPa. For oil-lubricated or chemical-duty variants, FKM rubber and SiC faces are available as options—all from our ISO 9001 workshop at wholesale cost.