USED JOHNSON PUMP (PART OF SPX FLOW) HR 21 – A MODEL DESIGNATION IN THEIR CENTRIFUGAL PUMP LINE.

3/4″ X 1-1/2″ SHAFT OUTPUT
The Johnson Pumpen HR 21 with a 1:3.1 drive ratio refers to a centrifugal pump model likely used in marine, industrial, or OEM applications, typically driven by a mechanical drive or motor with a reduction gear ratio. Here’s a breakdown of what the components likely mean:
🔧 Component Overview
✅ Johnson Pumpen HR 21
Brand: Johnson Pump (part of SPX FLOW)
Model: HR 21 – A model designation in their centrifugal pump line.
Type: Centrifugal pump
Applications: Common in marine (cooling, bilge), industrial fluids, water circulation, or light-duty chemical processing.
⚙️ Drive Ratio 1:3.1
This refers to a gear reduction system.
1:3.1 ratio: The pump shaft rotates 3.1 times for every 1 rotation of the drive shaft.
Typically used to increase RPMs at the pump for higher flow rates while using a slower motor/engine.