A 5 HP ring blower moves roughly 400 to 530 m³/hr of oil-free air and reaches about 330 mbar of pressure or -290 mbar of vacuum, drawing 3.73 kW. It is the size most mid-scale effluent and sewage plants land on: enough head for a 2.5–3 m aeration tank, enough flow to run a full diffuser grid, and still a single compact, oil-free unit. The 5.5 HP variants push flow higher when head is modest, and a double-stage option covers the jobs that need more pressure than any single-stage 5 HP can give.
Picture a mid-size ETP with a 3 m deep aeration basin. The plant designer needs air at the diffuser at roughly 294 mbar of water head plus 30–50 mbar of diffuser loss plus pipe losses — call it ~350 mbar total. That single number decides almost everything about which 5 HP model works, so we start there and work outward.
The pressure ceiling decides the model
At 3 m submergence the demand is right at the top of the single-stage 5 HP envelope. The YEBL-1-400 delivers 400 m³/hr and tops out at 330 mbar — it will comfortably run a 2.5 m tank and handle a 3 m tank only if pipe and diffuser losses are kept tight. If your basin is deeper than 3 m, or your loss budget is generous, a single-stage 5 HP runs out of head. That is where a YEBL-DS-230 double-stage unit earns its place: two impellers in series push -340/410 mbar at 230 m³/hr, trading flow for the extra pressure a deep tank needs.
The 5 HP class, as a selection matrix
Rather than a flat spec dump, here is each model paired with the duty it wins. Flow, vacuum and pressure are published catalog values.
| Model | Power | Flow (m³/hr) | Vacuum / Pressure (mbar) | Noise (dB) | Choose it when |
|---|---|---|---|---|---|
| YEBL-1-400 | 5.0 HP | 400 | -290 / 330 | 77 | You need the highest single-stage pressure at 5 HP — up to ~3 m tanks |
| YEBL-1-530L | 5.5 HP | 530 | -200 / 200 | 70 | Flow matters more than head — shallow tanks, large diffuser grids, quiet running |
| YEBL-1-700F | 5.5 HP | 700 | -150 / 140 | 78 | Maximum air volume at low head — big ponds, surface agitation |
| YEBL-DS-230 | 4.0 HP | 230 | -340 / 410 | 72 | Head exceeds single-stage — deeper tanks, higher back-pressure conveying |
Note the trade the table makes visible: the YEBL-1-530L moves a third more air than the YEBL-1-400 but only reaches 200 mbar, while the double-stage YEBL-DS-230 sacrifices flow to clear 410 mbar. Horsepower is nearly constant across the first three rows — the geometry, not the motor, sets the behaviour.
Where each 5 HP model fits
Mid-scale STP and ETP aeration
For sewage and effluent plants the deciding factor is tank depth, and the YEBL-1-400 is the default 5 HP aeration choice for tanks up to 3 m because it holds 330 mbar while still delivering 400 m³/hr. Confirm the full head-plus-loss sum before committing — a diffuser grid that is dirty or undersized raises back-pressure and eats your margin. The effluent treatment plant application page covers diffuser layout and blower redundancy (most plants run duty-plus-standby). The physics of head and loss is laid out in the complete guide to ring blowers.
Larger ponds and aquaculture
Where basins are shallow but wide, flow beats pressure. A YEBL-1-530L at 530 m³/hr, or a YEBL-1-700F at 700 m³/hr, spreads air across a large surface at modest head — and the 530L's 70 dB rating keeps a pond-side install civil.
Pneumatic conveying and process vacuum
For dilute-phase conveying of light powders and pellets, the 5 HP class supplies the pressure or vacuum that carries material through the line. Conveying back-pressure can climb quickly with line length and bends, so if your route is long, the double-stage YEBL-DS-230's 410 mbar ceiling gives the margin a single-stage cannot.
The energy argument for right-sizing
A 5 HP motor draws 3.73 kW, and a 5.5 HP motor about 4.1 kW, at full load. On a plant that aerates around the clock, that difference — and any oversizing beyond it — runs up a real annual bill. Two habits keep energy honest at this size. First, size to the working duty point, not the free-air flow: a ring blower pulls the least power near open flow and works hardest near its pressure ceiling, so a machine forced to run close to its ceiling all day costs more than one sized with headroom. Second, if air demand swings through the day — a plant with variable load, a batch process — a VFD lets you trim impeller speed to match, which cuts power roughly with the reduction in flow rather than wasting it across a throttle valve. Throttling to reduce flow saves almost nothing and heats the machine; speed control saves energy and runs cooler.
Reading flow at your working pressure
The catalog flow is the top of the curve, reached only near zero back-pressure. As back-pressure rises toward the ceiling, delivered flow falls. So a YEBL-1-400 rated 400 m³/hr at up to 330 mbar does not give 400 m³/hr at 330 mbar — it gives its full flow near open discharge and less as it climbs. Size against the flow the curve shows at your actual working head, and your diffuser grid will get the air you designed for instead of a disappointing fraction of it.
Electrical, cooling and protection
The 5 HP class is almost always three-phase. A few practical rules:
- Size the overload and cable to the motor full-load current, and confirm supply voltage under load — low voltage makes the motor draw more current and run hot.
- Never throttle the outlet to "tune" flow. A ring blower cools by the air it pumps; a restricted or deadheaded outlet converts that airflow into heat and can trip or damage the unit. Fit a YBPRV-125 or YBPRV-400 relief valve sized to the operating band.
- Filter the inlet. A YEBL-FA-4.0 assembly (880 m³/hr, 4" port) protects impeller clearance on the higher-flow 5.5 HP units; the YEBL-FA-2.0 suits the YEBL-1-400.
- Consider a VFD if your air demand varies through the day — trimming speed saves energy and reduces noise, and three-phase motors take drives cleanly.
Sizing up or down from 5 HP
If your head sum lands comfortably under 200 mbar and flow under 350 m³/hr, you may be over-buying — the 2 HP ring blower guide covers that lighter band. If a single 5 HP unit cannot hold your duty point, or you need duty-plus-standby at higher flow, move up to the 10 HP and above range, where the YEBL-1-530P delivers 530 m³/hr at 380 mbar.
A working rule for the 5 HP band: single-stage for tanks up to ~3 m and conveying under ~300 mbar; double-stage the moment your total head crosses ~350 mbar at this flow.
Get the model confirmed against your numbers
Send us your tank depth, diffuser count and line length, and we will match the exact 5 HP model and relief-valve setting to the published curves before you commit budget. Message the Yash Blowers team on WhatsApp at +91 9311693322 or email sales@yashblowers.org for a same-day recommendation and quotation.