FBCN vs FBOT — standardized centrifugal or thermal oil?
Both share the centrifugal principle and back-pull-out construction. The decision point is temperature: up to 260°C FBCN handles it; above 260°C — up to 350°C — FBOT is the path.
TL;DR — Direct answer
FBCN covers industrial processes with clean or turbid liquids up to 260°C and 2,200 m³/h. FBOT is dedicated to organic thermal oils up to 350°C with dual sealing (graphite packing + mechanical seal submerged in bearing oil).
FBCN
Standardized centrifugal · 260°C
When to use
- Clean or turbid liquids up to 260°C
- Chemical, petrochemical, paper, mining
- Flow up to 2,200 m³/h
- Head up to 135 m
- API 610 12th edition
FBOT
Thermal oil · 350°C
When to use
- Organic thermal oils up to 350°C
- Industrial heating systems
- Pharmaceutical, chemical, food, textile, plastics
- Fluid free of abrasive particles
- Dual-sealing system mandatory
Side by side
| — | FBCN | FBOT |
|---|---|---|
| Primary application | General industrial process | Industrial heating with thermal oil |
| Maximum temperature | 260°C | 350°C |
| Sizes | DN 25 to 300 mm | DN 25 to 300 mm |
| Maximum flow | 2,200 m³/h | 2,200 m³/h |
| Maximum head | 135 m | 135 m |
| Maximum rotation | 3,500 rpm | 3,500 rpm |
| Main standard | API 610 12th edition | ANSI B16.42 150 lbs or DIN EN 1092-2 PN16 flanges |
| Sealing | Packing up to 105°C (12 bar @ 125 lbs) or mechanical seal 90°C, 10 bar | Dual: graphite packings + mechanical seal submerged in oil |
| Construction | Back-pull-out · spiral body with feet | Back-pull-out · spiral body without feet · dual bearing |
| Test pressure | Per ASME B73.1 | 1.5× operating pressure |
Frequent technical questions
If process runs at 240°C with thermal oil, which to use?
If the fluid is organic thermal oil, always FBOT — even at 240°C. FBOT's construction is dedicated: dual sealing system maintains bearing thermal stability, and the design without feet avoids differential thermal expansion. FBCN covers 260°C, but for thermal oil FBOT is the correct specification per manual.
Can FBCN handle small particulates?
Yes — FBCN was developed for "clean or turbid liquids" per the manual. For fluids with suspended solids, the manual recommends consulting FB for appropriate sealing chamber specification.
Can FBOT be used for high-temperature water?
Not the recommended application. The FBOT manual literally states: 'The fluid must not contain abrasive particles or materials that chemically attack the pump components.' FBOT was designed for organic thermal oils. For steam or hot water, consult FB — likely FBCN with appropriate sealing chamber.
Are both back-pull-out?
Yes. Both allow removing the rotor+bearing assembly without disconnecting the piping — reduces downtime hours in preventive maintenance.
Still unsure?
FB's application engineer evaluates your process conditions — fluid, temperature, flow, viscosity — and points to the right series.
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