Overview
The Ruffy is what you reach for when the liquid is full of hard, abrasive solids — sand, grit, gravel, that sort of thing. The design is dead simple on purpose: no screening needed because the open vane impeller handles it, no priming because the casing sits below the liquid, and no bearings or seals underwater to wear out and cause headaches.
You can get it in standard mount or flange motor mount. For power, there’s direct coupling at 2.2kW or 3kW, or belt drive at 4kW or 5kW if you need more grunt. The impeller is CNC machined from 4140 steel with a deep open vane design that just eats through whatever you throw at it.
What Sets It Apart
The open vane impeller handles solids without any pre-filtering.
Won’t damage itself if the pit runs empty. Handy for intermittent use.
No bearings, no seals below the liquid line. Less maintenance, fewer problems.
2.2–3kW direct coupled, or 4–5kW belt drive for heavier applications.
Common Applications
How Pit Depth Works
Column length is measured from the bottom of the pump casing to the high water level mark just below the top bearing. Measure your pit from bottom to where you want the max level, and pick the closest size. If you’re between two, go longer — you can always run with extra column, but you can’t run short.
Reading the Model Numbers
Ruffy models follow this pattern: [Length Prefix][F for Flange][Outlet Size]
Length: SR = Short (2’6″), BR = Basic (3′), CR = (3’6″), MR = Medium (4′), LR = Long (5′), XLR = Extra Long (6′)
Mount: No suffix = Standard mount, F = Flange motor mount
Outlet: 50 = 2″ (50mm) BSP discharge (all models)
So an LRF50 is a Long (5′ / 1.52m), Flange mount, 2″ outlet.
Available Sizes
| Prefix | Imperial | Metric | Mount |
|---|---|---|---|
| SR | 2’6″ | 0.76m | Standard |
| BR | 3′ | 0.91m | Standard |
| CR | 3’6″ | 1.07m | Standard |
| MR | 4′ | 1.22m | Standard |
| LR | 5′ | 1.52m | Standard |
| XLR | 6′ | 1.83m | Standard |
| SRF | 2’6″ | 0.76m | Flange |
| BRF | 3′ | 0.91m | Flange |
| CRF | 3’6″ | 1.07m | Flange |
| MRF | 4′ | 1.22m | Flange |
| LRF | 5′ | 1.52m | Flange |
| XLRF | 6′ | 1.83m | Flange |
Technical Specs
Performance Curve
All Models
Standard Mount
Flange Mount
Give us a call for pricing on any model.
Spare Parts
All genuine DUMAC parts. We keep the common ones on the shelf so you’re not waiting around. Ring us for pricing and availability.
| Part No. | Description |
|---|---|
| 50-R1 | Pump Casing |
| 50-R2 | Impeller – CNC 4140 |
| 50-R3 | Suction Cover (2’6″, 3′, 3’6″) |
| 50-RL3 | Suction Cover (4′, 5′, 6′) |
| 50-R4 | Upper Tube Flange |
| 50-R6-S | Pump Shaft 2’6″ (1.5″ Dia.) |
| 50-6A-B | Pump Shaft 3′ (1.5″ Dia.) |
| 50-R6-C | Pump Shaft 3’6″ (1.5″ Dia.) |
| 50-R6-M-FM | Pump Shaft 4′ (1.5″ Dia.) 63″ |
| 50-R6-L-FM | Pump Shaft 5′ (1.5″ Dia.) 75″ |
| 50-R6-XL-FM | Pump Shaft 6′ (1.5″ Dia.) 87″ |
| 50-R10 | Lower Flanged Bearing Assembly |
| 50-R11 | Upper Flanged Bearing Assembly |
| 50-R10a/11a | Self Aligning Bearing Only |
| 50-R12 | Flexible Coupling Complete (M/Im) |
| 50-R12a | Flexible Coupling Complete |
| 50-R12b | Flexible Coupling Rubber Spider |
| 50-R19 | Impeller Nut |
| 50-RL31 | Bearing Housing |
| 50-RL34 | Lower Bearing |
| 50-RL35 | Upper Bearing |
| 50-RL36 | Lower Thrust Spacer & Collar |
| 50-RL37 | Upper Thrust Spacer & Collar |
| 50-R24 | Casing Cap & Screws (3) |
This covers the most commonly needed parts. If you need something specific — a particular shaft length, or anything that’s not listed here — just get in touch and we’ll sort it out.





