Dean RA and Dean RWA are both air-cooled centrifugal pumps. They are not interchangeable by fluid.
Selection starts with the liquid:
- RA for heat transfer oil
- RWA for hot water, ethylene glycol, propylene glycol, and triethylene glycol
Get the fluid right first. Temperature, flow, head, and mounting come after.
Air-cooled arrangement
Both series use shaft-fan air cooling. A finned bearing frame removes heat from the bearings and seal chamber. Neither series needs external water cooling.
Why the series must match the fluid
Dean selected different mechanical seal packages, elastomers, and seal-cavity auxiliaries for each fluid service.
RA (heat transfer oil)
The RA mechanical face seal is selected for common heat transfer oils.
- Stationary face: silicon carbide and Viton
- Rotary face: stainless steel, carbon, and Viton
- Gland gasket: Viton
- Casing gasket: Grafoil
Between the stationary seal and the front grease seal is a barrier-fluid cavity. It keeps oxygen off the seal faces when the oil oxidizes. The cavity is charged with nitrogen or barrier oil per the installation practice for that pump.
RWA (hot water, EG, PG, TEG)
The RWA mechanical face seal is selected for hot water and glycols. Seal faces are lubricated by the pumped liquid. The seal cavity must be vented on fill.
- Stationary face: silicon carbide and Aflas
- Rotary face: stainless steel, carbon, and Aflas
- Gland gasket and sleeve gasket: Aflas
- Front grease seal: Viton
- Casing gasket: Teflon
RWA includes a Dean Air Vapor Eliminator on top of the pump. It removes vapor that forms at the seal faces when aqueous or glycol liquids vaporize. These pumps are for hot water, ethylene glycol, propylene glycol, and triethylene glycol.
Practical rule
| RA | RWA | |
|---|---|---|
| Fluid | Heat transfer oil | Hot water, EG, PG, TEG |
| Cooling | Shaft-fan air-cooled | Shaft-fan air-cooled |
| Seal elastomers | Viton | Aflas (grease seal Viton) |
| Seal cavity | Barrier fluid (Nā or barrier oil) | Vented on fill; faces lubricated by pumped liquid |
| Auxiliary | Barrier-fluid cavity | Air vapor eliminator |
| Casing gasket | Grafoil | Teflon |
Series envelopes
| RA | RWA | |
|---|---|---|
| Service fluid | Heat transfer oil | Hot water, EG, PG, TEG |
| Max temperature | 650°F (343°C) | 400F (205°C) |
| Flow | Up to 6,000 GPM | Up to 1,100 GPM |
| Head | Up to 425 ft | Up to 425 ft |
| Pressure | Up to 350 psig | Up to 450 psig |
| Sizes (factory) | 27 | 13 |
| Material (typical) | Ductile iron | Ductile iron |
| Cooling | Air-cooled, finned frame | Air-cooled, finned frame |
RA is not an ANSI B73.1 pump. Dimensional interchange notes on some frames are envelope and piping notes, not a fluid or series swap.
Fluid-first decision path
- Identify the pumped liquid.
- If it is heat transfer oil, stay in RA (Viton seal package, barrier-fluid cavity, Grafoil casing gasket).
- If it is hot water, ethylene glycol, propylene glycol, or triethylene glycol, stay in RWA (Aflas seal package, vapor eliminator, Teflon casing gasket).
- Confirm temperature against the series maximum (650°F RA / 400°F RWA).
- Confirm flow, head, and pressure against the series envelope.
- Select frame and size within that series.
- Confirm actual impeller diameter before ordering parts or a trimmed rotating element.
If the liquid is mixed, dirty, or not clearly oil versus water/glycol, stop and call. Series selection is not a guess.
Data needed for selection
Send or record:
- Fluid name and composition (oil grade, glycol type and concentration if known)
- Operating and design temperature
- Specific gravity
- Viscosity at operating temperature
- Required flow
- Required head or differential pressure
- Suction condition and vapor pressure (NPSH available if known)
- Continuous or intermittent duty
- Preferred mounting (foot vs centerline) and space limits
- Motor preference (hp, rpm, voltage, enclosure) if already specified
- Nameplate data if replacing an installed Dean pump
For a replacement, also collect pump size/model and, when practical, the measured impeller diameter. On Dean RA and RWA, OEM heater builders often trim a full-size impeller and may not restamp the tag. Size/model plus actual impeller diameter matter more for parts than the serial number. See the nameplate guide for the verification steps.
Frames inside each series
RA frames commonly sold for heat transfer oil service include:
RWA is the water/glycol family. Select RWA only after the fluid check passes. Frame choice inside RWA follows the same rule as RA: match size/model and verified impeller diameter, then options.
Series overview: https://pumpresource.us/pumps/dean-pumps/ra-series/
When to call
Call before ordering if:
- The fluid is not clearly heat transfer oil or water/glycol
- Temperature is near the series limit
- Viscosity is high or unknown at operating temperature
- NPSH is marginal
- You are replacing an unlabeled or OEM-trimmed pump
- The tag impeller diameter has not been verified
- Seal faces, elastomers, or vapor eliminator condition need a parts match
- The duty needs a factory size not shown as a live store frame
Pump Resource: 888-341-7085, sales@pumpresource.us.
Quick reference
| Question | Answer |
|---|---|
| Hot oil? | RA |
| Hot water or glycol? | RWA |
| Cooling | Both shaft-fan air-cooled |
| Seal package | Viton + barrier cavity (RA); Aflas + vapor eliminator (RWA) |
| Shared wet-end parts between RA and RWA? | No. Select by series first. |
| What to verify on a replacement? | Size/model, then actual impeller diameter |
Bottom line
RA and RWA are both air-cooled. Choose RA for heat transfer oil. Choose RWA for hot water and glycol. Then size the pump, and verify impeller diameter before parts leave the shelf.