Can you make a fan leak-tight enough to serve as a containment barrier, and prove it?
Yes. We build a welded, pressure-tested casing and leak-test it to a stated tightness class, select the shaft seal (stuffing-box or mechanical) for that class, and gasket and torque-control the access joints. The finished fan gets a documented leak-rate test before it leaves the floor, so you receive a measured leak figure, not an assumption. Tell us the leak class and the containment pressure and we engineer the casing and seal to it — a containment fan is a barrier first and a mover second.
How do you handle redundancy so a single fan failure never opens the containment?
We supply matched duty/standby (N+1) fans built to one engineering convention, so either machine carries the full duty and a swap-over is seamless. Bearing life is sized conservatively (a long L10h), and we provide vibration and temperature monitoring provisions so a warning triggers a controlled change-over rather than a trip. Construction lets a wheel or bearing be serviced without breaching the running train. Redundant by design — a single failure is engineered out, not hoped away.
Can the fan be seismically qualified, and what documentation comes with it?
Yes. We design and document a seismic-qualified support and hold-down to your stated response spectrum, and issue a complete data book — GA drawing, design calculations, material test certificates with heat traceability on the pressure boundary, documented welds with NDT to the specified extent, and the in-house performance and balance reports. The data book is issued for your review before dispatch. A fan that performs but cannot be documented and qualified is of no use in a controlled facility, so we agree the documentation scope up front.
How do you keep the HEPA exhaust and fume-hood extract working as the filters load?
We size the fan on the loaded filter bank, not a clean one, so the curve still delivers the required static as the HEPA resistance climbs and hood face velocity holds through the filter life. The fan sits downstream of the HEPA stage on clean air, so the wheel is chosen for efficiency and a stable, non-overloading curve. Give us the clean and dirty filter resistances and the face-velocity target, and we engineer the duty point across the loading range rather than at one point.
The air is clean here, so which fan do you pick and why not a dust-type wheel?
Because the gas is clean, we pick for efficiency, low noise and a well-behaved curve rather than for shedding dust. An aerofoil wheel gives the highest efficiency and lowest noise on large clean-air containment and HEPA extract; a backward-curved plate wheel is the robust, non-overloading general and HEPA workhorse; and a backward-flat plate wheel suits corrosive or emergency extract where a rugged, easily inspected blade matters more than peak efficiency. A rugged dust-type radial would just cost you efficiency and noise you do not need to spend here.
Do you performance-test the fans, and what about AMCA, CE, ATEX and quality certification?
Every fan is performance-tested in-house to the AMCA 210 / ISO 5801 method on our 200 HP VFD test rig, and dynamically balanced to ISO 21940 G6.3 as standard (G2.5 / G1.0 on application). To be precise: that in-house testing is to the AMCA 210 / ISO 5801 method, not AMCA-certified, and we are not an AMCA member; CE is self-declared per 2006/42/EC and 2014/35/EU, and ATEX Zone 2/22 is self-declared per 2014/34/EU (Category 3) where the area classification calls for it — those are self-declarations of conformity, not third-party certifications. Our only third-party certification is ISO 9001:2015. Any facility-specific quality or nuclear-grade programme requirements we treat as project-specific scope, agreed and documented up front.
