

Pump — Complete Guide Normalized Centrifugal
Technical guide on normalized centrifugal pumps: what normalization means, what ASME B73.1 standardizes, back pull-out advantages, and what the standard does — and does not — cover in a replacement.
TL;DR
A normalized centrifugal pump follows standardized dimensions (ANSI/ASME B73.1 — the same standard, historically designated ANSI) ensuring interchangeability between manufacturers — same base, flanges and shaft.
Back pull-out construction allows removing the rotating assembly without disconnecting piping — reduces maintenance time and process downtime.
Replaces the installed normalized centrifugal pump of the same dimension designation, from any manufacturer — same installation footprint.
FB Bombas FBCN series: 53 models (43 standard DN25-150 + 10 large capacity DN200-300), flow up to 2,200 m³/h, head up to 135 m, 260°C and rotation up to 3,500 rpm.
Every FBCN leaves the factory hydrostatically tested at 1.5× design pressure with its Q×H curve measured on an in-house bench — Data Book traceable by serial number.
ASME B73.1 (mechanical) compliance, manufactured in Cabreúva-SP since 1944, CRCC Petrobras Family 6 registered.
Updated
What is a normalized centrifugal pump?
A normalized centrifugal pump follows the standardized dimensions of ASME B73.1: pumps of the same standard dimension designation, from any source of supply, are interchangeable as to mounting dimensions, size and location of suction and discharge nozzles, input shaft, baseplate and foundation bolt holes. What the standard fixes is the installation envelope — not the internal parts, which follow each manufacturer's own design. FB Bombas' FBCN Series is horizontally normalized with 53 models (43 standard + 10 large frames) covering up to 2,200 m³/h. CRCC Petrobras registered.
What is back pull-out?
Back pull-out is a construction design that allows removing the rotating assembly (impeller, shaft, seal, bearing) from the rear of the pump without disconnecting the volute from piping. Drastically reduces maintenance time and downtime cost — essential in industrial plants with 24/7 continuous operation. The entire FBCN Series is back pull-out. This is what the FBCN technical manual (MTEC-03/00) specifies: "back-pull-out construction, which allows the bearing assembly to be removed from the volute without disconnecting and misaligning the pumping piping" (translated from the Portuguese original).
Can I replace the normalized centrifugal pump already installed with a FBCN?
In many cases, yes — and it is the standard that makes it possible without civil work. Under ASME B73.1, pumps of the same dimension designation are interchangeable as to mounting, nozzles, shaft and baseplate, regardless of who built the unit in service. The FBCN is a candidate whenever the designation matches. Equivalence is confirmed model by model from the dimensional drawing, shaft centre, flange position and class, baseplate, coupling, Q×H duty point, NPSHr and power — a matching designation does not by itself imply the same hydraulics. FB Bombas supplies the complete pump, not loose parts for third-party equipment. Brazilian manufacturer since 1944, CRCC Petrobras, compliant with ASME B73.1.
Is there a Brazilian manufacturer of normalized centrifugal pumps?
Yes. FB Bombas' FBCN Series is a normalized centrifugal pump manufactured in Brazil: compliant with ASME B73.1, back pull-out construction, 53 models up to 2,200 m³/h and 135 m. Objective differentiators: continuous operation since 1944 under the same corporate registry (predating Petrobras itself), engineering and factory in Cabreúva-SP, spare parts for FB pumps without currency exposure and CRCC Petrobras Family 6 qualification — Rotating Equipment.
What is the difference between normalized and non-normalized?
Normalized follows standardized mounting, nozzle and shaft dimensions: pumps of the same dimensional designation swap for one another, whatever the source of supply. Non-normalized has proprietary dimensions, requiring modifications or complete replacement when swapped. In industrial plants, normalized is preferred for reducing maintenance time, parts inventory cost and single-supplier dependency.
What Is a Normalized Centrifugal Pump?
Dimensional standardization that ensures industrial interchangeability

A normalized centrifugal pump follows dimensions standardized by a dimensional standard — for the FBCN, ASME B73.1. This means the base dimensions, suction and discharge connections, shaft height and mounting points follow the same pattern among manufacturers adopting the standard — making direct replacement technically feasible when equivalence is confirmed model by model from the dimensional drawing, flanges, baseplate and duty point.
The FB Bombas FBCN series is horizontally normalized with back pull-out design, allowing complete removal of the rotating assembly without disconnecting the volute from piping. This reduces maintenance time from hours to minutes — essential in plants with 24/7 operation.
ASME B73.1 — dimensional interchangeability across pumps of the same designation
Back pull-out — maintenance without disconnecting piping
53 models — flow up to 2,200 m³/h, head up to 135 m
Cast iron, stainless steel or special alloys
How Does a Centrifugal Pump Work?
Kinetic energy to pressure conversion cycle
Axial Suction
Fluid enters through the impeller center (eye) by pressure difference. Rotation creates a low-pressure zone at the center that draws liquid through the suction piping.
Radial Acceleration
Impeller vanes accelerate the fluid radially through centrifugal force. The motor's mechanical energy is transferred to the fluid as kinetic energy (velocity).
Volute Conversion
The high-velocity fluid enters the volute (spiral casing), where the cross-section progressively expands. Deceleration converts kinetic energy into static pressure.
Back Pull-Out & Normalization
Technical advantages of dimensional standardization
Back Pull-Out
Rotating assembly removal from rear without disconnecting volute from piping. Maintenance in minutes, not hours. Reduces downtime cost in 24/7 plants.
Interchangeability
Pumps sharing the same ASME B73.1 dimensional designation share mounting dimensions, nozzles, shaft and baseplate bolt holes — the swap needs no civil work or piping rework. Duty point, NPSHr, flanges and materials are checked on the data sheet.
International Standard
ASME B73.1 — mounting dimensions and mechanical construction requirements for the horizontal end-suction process pump. Traceability in industrial audits.
Lower TCO
Lower total cost of ownership: standardized spare parts, reduced inventory, manufacturer independence and faster maintenance throughout service life.
Centrifugal Pump Advantages
Why industry prefers normalized pumps
High Flow Rates
Capability to move massive fluid volumes. FBCN series handles up to 2,200 m³/h.
Energy Efficiency
High efficiency at operating point (BEP). Lower energy cost per m³ pumped for low-viscosity fluids.
Simple Maintenance
Back pull-out allows removal of rotating assembly without disconnecting piping. Reduces downtime.
Normalized
Standardized dimensions ensure parts interchangeability and easy replacement between manufacturers.
Continuous Flow
No pulsation — smooth, constant flow. Ideal for processes requiring stable line pressure.
Cost-Effective
Lower acquisition and operating cost for low-viscosity applications. Wide parts availability.
Industrial Applications
Sectors that use centrifugal pumps daily
Industrial Water
Intake, distribution and recirculation
Chemical Processes
Solvents, dilute acids and bases
Fire Fighting
NFPA 20 systems, sprinklers, hydrants
HVAC & Building
Air conditioning, cooling towers
Pharmaceutical
Purified water, light solvents
Mining
Drainage, dilute slurry transport
Sugar & Ethanol
Juice, vinasse, boiler water
Centrifugal vs. Gear
When to choose each pumping technology
| Criteria | Centrifugal | Gear |
|---|---|---|
| Ideal viscosity | Low (<100 cP) | High (>100 cP) |
| Max flow | Very high (2,200 m³/h) | Moderate (6,500 L/min) |
| Self-priming | No | Yes |
| Efficiency with water | Excellent | Limited |
| Operating cost | Lower (low visc.) | Lower (high visc.) |
| Best for | Water, solvents, effluents | Oils, resins, asphalt |
How to Specify
Essential data for correct sizing
Flow & Head
Desired flow rate (m³/h) and total head (m). Defines the operating point on the Q×H curve.
Fluid Type
Name, viscosity, density, solids concentration and chemical compatibility.
Temperature
Operating and maximum temperature. Defines seal materials and construction type.
Available NPSH
Suction height, piping losses and reservoir pressure. Prevents cavitation.
Installation
Suction and discharge diameters, flange type, available space and base.
Operating Regime
Continuous or intermittent, start frequency, load variation and applicable standards.
Frequently Asked Questions
What is a standardized centrifugal pump?
A standardized centrifugal pump follows specified dimensions and parameters that ensure interchangeability between manufacturers — same baseplate, same connections, same dimensions. This reduces replacement costs, simplifies spare parts inventory, and eliminates dependence on a single supplier.
Are ANSI B73.1 and ASME B73.1 the same standard?
Yes. The specification for horizontal end-suction centrifugal pumps for chemical process was born as ANSI B73.1 and is maintained today by ASME — which is why catalogs list it as "ANSI B73.1", "ASME B73.1" or "ANSI/ASME B73.1". The technical reference is the same: standardized dimensions (baseplate, flanges, shaft) interchangeable across manufacturers. In practice, an existing "ANSI-standard" pump can be replaced by an FBCN of the same dimensional designation without redoing base or piping.
What is back pull-out?
Back pull-out is a design feature that allows removing the rotating assembly (impeller, shaft, mechanical seal, bearing housing) from the rear of the pump without disconnecting the volute from the piping. This drastically reduces maintenance time and downtime costs — essential in industrial plants with continuous operation. This is what the FBCN technical manual (MTEC-03/00) specifies: "back-pull-out construction, which allows the bearing assembly to be removed from the volute without disconnecting and misaligning the pumping piping" (translated from the Portuguese original).
Is the FBCN a bearing-frame (long-coupled) or close-coupled pump?
The FBCN is a bearing-frame (long-coupled) centrifugal pump: the rotating assembly runs on its own bearing frame, coupled to the motor through a flexible coupling — the construction the FBCN manual describes as back pull-out, allowing removal of the bearing assembly without disconnecting the volute from the piping. It is the opposite of a close-coupled (monobloc) pump, where the impeller mounts directly on the motor shaft end. Bearing-frame construction eases maintenance, alignment and seal replacement in continuous industrial operation.
What certifications does FB Bombas hold?
FB Bombas is registered with CRCC Petrobras and meets API 610 (special solutions) and API 676 (gear) requirements. The FBCN series is a horizontal pump standardized per ASME B73.1 with back pull-out design. Available in cast iron, stainless steel, and special alloys.
What applications are standardized pumps suited for?
Industrial water, chemical processes, cooling systems, HVAC, sugar-ethanol plants, mining, pulp and paper, fire-fighting, and any application requiring low-viscosity fluids at high flow rates with simplified maintenance and parts interchangeability.
What is the difference between a standardized and a non-standardized pump?
A standardized pump follows specified dimensions (baseplate, flanges, shaft) allowing interchange between manufacturers. A non-standardized pump has proprietary dimensions, making replacement difficult. In industrial plants, standardized pumps are preferred because they reduce maintenance time and eliminate dependence on a single manufacturer.
What is the operating range of the FBCN series?
Flow rate up to 2,200 m³/h, head up to 135 m, temperature up to 260°C. 53 models: 43 standard (DN25 to DN150) + 10 large capacity (DN200 to DN300) in various impeller configurations and construction materials.
Can I replace the standardized pump already installed with an FBCN?
In many cases, yes. Under ASME B73.1, pumps of the same dimension designation are interchangeable as to mounting, nozzles, shaft and baseplate, whoever manufactured the installed unit — the FBCN is a candidate whenever the designation matches. Equivalence is confirmed model by model: dimensional drawing, shaft centre, flanges, baseplate, coupling, Q×H duty point, NPSHr and power. Back pull-out for fast maintenance. FB Bombas supplies the complete pump, not loose parts for third-party equipment. Brazilian manufacturer since 1944, CRCC Petrobras registered, ASME B73.1 compliant.
What construction materials are available for the FBCN?
The FBCN is available in cast iron GG20 (industrial water, sanitation, low corrosion), A216 WCB carbon steel (chemical and petrochemical, up to 25 bar depending on flange), nodular iron (reinforced mechanical strength), and A743 CF8M (316) stainless steel for acidic or corrosive fluids. FB Bombas engineering validates the specification against the chemical compatibility table for the supplied fluid.
What is the 0/100/150 % curve envelope and why does it matter?
The 0/100/150 % envelope is the NFPA 20 requirement (also adopted by NBR 16704) defining Q×H curve points at zero flow (shutoff), nominal, and 150 % of nominal. The pump must deliver at least 65 % of head at 150 % flow and no more than 140 % of nominal head at shutoff. The FBCN specified for fire protection ships with a factory-certified curve at these three points for Fire Department approval.
Does the FBCN have any high-capacity variant beyond the 43 standardized models?
Yes. Beyond the 43 ASME B73.1 standardized models (DN25 to DN150, flow up to 1,000 m³/h), the FBCN has 10 large-bore models (DN200 to DN300) for flows up to 2,200 m³/h and head up to 135 m, retaining back pull-out construction and the same material options. The 53 models cover the full industrial application range without resorting to a split-case pump.
Is there a Brazilian manufacturer of normalized centrifugal pumps?
Yes. FB Bombas' FBCN Series is a normalized centrifugal pump manufactured in Brazil: compliant with ASME B73.1, back pull-out construction, 53 models up to 2,200 m³/h and 135 m. Objective differentiators: continuous operation since 1944 under the same corporate registry (predating Petrobras itself), engineering and factory in Cabreúva-SP, spare parts without currency exposure and CRCC Petrobras qualification.
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