Grundfos 98848074 CR3-7 Vertical Multistage Pump

Grundfos 98848074 / CR3-7 A-A-A-V-HQQV Vertical Multistage Centrifugal Pump

The Grundfos 98848074 designates the CR3-7 A-A-A-V-HQQV inline vertical multistage centrifugal pump, engineered for high-head, non-self-priming liquid transfer in demanding marine auxiliary, industrial process, and pressure-boosting configurations. Configured with 7 operational stages featuring precision-machined AISI 304 (EN 1.4301) stainless steel impellers, intermediate chambers, and guide vanes housed within a cast iron base and top head (EN-GJL-200), this unit delivers stable, pulse-free hydraulic head across variable duty points.

Driven by an integrated, totally enclosed fan-cooled (TEFC) 3-phase asynchronous electric motor rated at 0.55 kW (0.75 HP) in a 2-pole configuration (2853–2859 RPM at 50 Hz, 3440–3450 RPM at 60 Hz), the assembly utilizes Grundfos’s balanced cartridge shaft seal system (HQQV: Silicon Carbide/Silicon Carbide primary seal faces, FKM/Viton elastomers). This mechanical seal construction resists abrasive particles, thermal cycling, and continuous discharge pressures up to 25 bar (PN 25 rating).

Model Details:

• Manufacturer Part Number (MPN): 98848074
• Legacy / Variant References: 96516654, 96516647 (Direct cross-variant or predecessor generation)
• Standard Pipe Connection: Oval Flange, Rp 1 (1″ Internal Threaded Flange)

Technical Details

OEM Replacement

• Direct Drop-In Replacement: Fits standard Grundfos CR3 series inline bases with 250 mm face-to-face port spacing and Rp 1 connection geometry.
• Predecessor Series Cross-Reference: Replaces legacy CRK2, CR2-70, and legacy CR3-7 (e.g., MPN 96516647, 96516654, 400107).
• System Integration: Compatible with Grundfos Hydro MPC, Hydro Multi-E, Hydro Multi-B booster skid packages, and standard marine auxiliary feed systems.

Frequently Asked Questions

What does the code CR3-7 A-A-A-V-HQQV mean on the Grundfos 98848074?

The alphanumeric designation breaks down as: CR (Centrifugal Multistage Inline family), 3 (nominal flow rate of 3 m³/h), 7 (7 impellers/stages), A (standard pump base version), A (oval flange connection), A (wetted parts in AISI 304 stainless steel), V (Viton/FKM elastomers), and HQQV (silicon carbide on silicon carbide cartridge seal with Viton secondary seal).

Can the Grundfos 98848074 be installed horizontally?

The standard CR3-7 is designed strictly for vertical orientation with the motor pointing vertically upwards. While Grundfos manufactures horizontal mounting conversion kits with specialized base supports, horizontal installation without appropriate brackets places severe overhung radial loading on the pump bearings and leads to premature seal failure.

What is the difference between HQQV and HQQE shaft seals in Grundfos CR pumps?

Both mechanical seals feature Silicon Carbide vs. Silicon Carbide (Q/Q) friction faces. The distinction lies in the elastomers: HQQV uses FKM (Viton), providing superior chemical resistance to oils, fuel traces, and hydrocarbons up to 90°C. HQQE uses EPDM, which is designed for standard hot water, heating systems, and potable water up to 120°C, but will degrade quickly if exposed to oils.

How do I configure the motor for 400V 3-phase shipboard supply?

For a 380–415V 50 Hz or 440V 60 Hz 3-phase grid, wire the motor terminal bridge links in the Star (Y) arrangement. Place the metal bridge links horizontally across terminals W2, U2, and V2, and connect your incoming three-phase supply lines directly to terminals U1, V1, and W1. Always verify motor plate data and test insulation resistance to earth before energizing.

How do I troubleshoot low discharge pressure on a CR3-7 pump?

First, check the motor rotation direction against the arrow on the motor cowl; running backwards still moves water but drops head capacity by 40–60%. Next, bleed the pump head of air pockets via the priming plug. If air is eliminated and rotation is correct, inspect the inline suction strainer for fouling, or inspect the impellers for cavitation erosion or foreign debris blockage.