High-Pressure Centrifugal Blower Supplier: Up to 500 mm WC, and What That Takes at the Wheel

NextAir Systems, Faridabad, India. Last reviewed October 2026.

Pressure is made at the tip of the wheel. A centrifugal blower raises pressure roughly in proportion to the square of its tip speed, so a blower for 500 mm WC spins its wheel far faster than one for 100 mm WC, and a lot follows from that: stress, noise, balance, bearing life. Understanding the link makes it easy to see why high-pressure blowers are specified with more care than ventilation fans, and where a single-stage centrifugal blower stops.

NextAir builds centrifugal blowers up to 500 mm WC (about 4.9 kPa) static pressure and 800 HP. This page shows what pressure costs at the wheel, and where our range ends.

At a glance

• Our standard maximum is 500 mm WC (about 4.9 kPa). It covers the low, medium and high pressure classes completely and the first part of the very high class, which runs from 381 to 3,556 mm WC.
• At an assumed pressure coefficient of 0.8, 500 mm WC needs a tip speed of about 101 m/s, which is about 1,930 rpm on a 1 m wheel.
• Above 500 mm WC, in the rest of the very high class, which includes pneumatic conveying and high-resistance process lines, are duties outside what we build.
• At about 5% of atmospheric pressure, the gas is also compressed a little across the blower, which the selection must allow for.

What pressure asks of the wheel

The pressure a centrifugal wheel develops is its pressure coefficient times half the gas density times the square of the tip speed. The coefficient depends on the wheel type and the design, and we use 0.6, 0.8 and 1.0 to bracket it, which is an assumption. Rearranged, the tip speed needed for a pressure is the square root of twice the pressure over the coefficient and density. The table calculates it for four pressures within our range, in air at 1.2 kg/m³.

Pressure from 250 to 500 mm WC doubles the pressure and raises the tip speed by 41%. At the top of our range the wheel is travelling at about 100 m/s, a high speed for a fan, and the same physics that makes it work also loads the wheel, the shaft and the bearings. That is why balancing matters so much at the top of the range: impeller unbalance shows up as vibration, bearing wear and noise, and it gets worse with speed and size. We balance blower impellers on our own computerised dynamic balancing machines.

Pressure classes, and where we sit

Blowers are commonly grouped into four pressure classes, set out in blower pressure classes. Our 500 mm WC maximum covers the low, medium and high classes entirely, and the very high class, which runs from 381 to 3,556 mm WC (about 3.7 to 34.9 kPa), only partly. Typical uses of the very high class are pneumatic conveying, deep-bed filtration and high-resistance process lines. Within our range, that means deep filters and long ducts, such as VOC and odor adsorber beds, which are usually well below 500 mm WC, and many process lines.

Power, and what 800 HP buys

Shaft power is airflow times pressure divided by efficiency. At 500 mm WC (4.9 kPa) and an assumed 75% total efficiency, each m³/s of airflow needs about 6.5 kW. Our 800 HP (597 kW) ceiling therefore corresponds to roughly 91 m³/s, about 328,758 m³/h, at the full pressure, though the real figure is confirmed for each selection. The motor and starting method become a major electrical decision at the top of the range, as covered in motors, drives and starting.

Compressibility at 5 kPa

Pressure of 4.9 kPa is nearly 5% of atmospheric pressure, so the gas is compressed slightly as it passes through the blower, and its density at the outlet is about 5% higher than at the inlet. The fan laws assume constant density, and the error is small at 5 kPa, but it is not zero, and the selection should say whether the pressure and power are at inlet density. Our guide to reading a blower datasheet lists the points to check.

Noise rises with pressure too. A wheel at 100 m/s tip speed makes more sound than one at 70 m/s, and the sound of a high-pressure blower is dominated by the blade passing tone and the flow. If the blower is near people, ask for the sound power by octave band, and check the level at the boundary with the calculation in sound power to sound at the fence. Silencers and enclosures are cheaper to plan at the start than to add afterwards.

Centrifugal or positive displacement?

Single-stage centrifugal blowers deliver large volumes at moderate pressure. When the pressure climbs beyond what a single centrifugal wheel can supply, or the process needs a constant volume against a varying resistance, positive-displacement machines enter the picture. Our comparison centrifugal versus positive displacement explains the choice, and where your duty is beyond 500 mm WC we tell you so at the start.

To compare suppliers see how to choose a centrifugal blower manufacturer.

What to send us for a quotation

• Airflow and static pressure at the duty point, in mm WC or Pa
• Gas, temperature, density and any dust or moisture
• The system resistance at clean and worst-case conditions
• Duty hours and control: fixed speed, VFD or damper
• Voltage, frequency and drive preference
• Sound limit if the blower is near people

Send these to us through our contact page and we will confirm whether the duty is inside our range and select the blower. See the centrifugal blower range, our guide to centrifugal blowers and the cement plants and mining and mineral processing pages. High-resistance beds like our VOC adsorbers use this class of blower.

Frequently Asked Questions