Overview of Single-Pump Variable Frequency Water Supply Unit
Traditional secondary water supply systems rely on elevated water tanks or large storage pools — taking up valuable space, requiring significant civil engineering investment, and frequently causing pipe pressure fluctuations, water hammer, and secondary water contamination. The single-pump variable frequency pump unit eliminates these problems with an integrated design that combines closed-loop PID pressure control, VFD variable-frequency soft start, and a diaphragm pressure tank into a single compact assembly.
Real-time pipe network pressure monitoring automatically adjusts pump speed to match actual demand, maintaining constant pressure without intermediate storage tanks. The sealed system runs unmanned, with no risk of secondary contamination.
Technical Parameters
| Flow Range | 2 – 200 m³/h |
| Head | 10 – 140 m |
| Motor Power | 0.55 – 45 kW |
| Rated Speed | 2,900 r/min |
| Max System Pressure | 1.6 / 2.5 MPa (configurable) |
| Pressure Control Precision | ≤ ±0.01 MPa |
| Medium Temperature | -15°C to +120°C |
| Wetted Materials | SUS304 / SUS316L stainless steel |
| Seal Type | Silicon carbide double-end mechanical seal |
Key Advantages
15-Year Design Life: SUS304/316L stainless steel wetted parts paired with silicon carbide double-end mechanical seals deliver corrosion and cavitation resistance. Designed service life exceeds 15 years — over 40% longer than traditional cast-iron pump and water tank combinations.
20%–50% Energy Savings: PID closed-loop frequency adjustment eliminates unnecessary full-speed operation. Combined with intelligent sleep mode during low-demand periods, annual electricity costs drop 30%–60%. VFD soft start also eliminates start-stop water hammer stress on pipe networks.
60% Smaller Footprint: No underground pool, no independent pump room. The pump set, electrical control cabinet, and diaphragm pressure tank are mounted on a single pre-fabricated base. Same water supply capacity, far less space required.
2-Hour Installation: Pre-assembled coupling base, factory pre-wired electrical connections. On-site steps: position the unit → connect piping → set VFD parameters. Deployment time cut in half compared to conventional systems.
45% Lower Maintenance Cost: Integrated layout allows daily inspection without dismantling main piping. A single technician completes pressure tank checks and sensor calibration within one hour.
Operating Conditions
Medium: Clean water or liquids with similar physical-chemical properties. Solid content ≤ 0.1% by volume, no long-fiber impurities.
Medium Temperature: -15°C to +120°C (standard / high-temperature options).
Ambient Conditions: Temperature 0–40°C, humidity ≤ 95% non-condensing.
Electrical Supply: 3-phase 380V ± 10% / 50 Hz (customizable).
Protection Ratings: IP54 (control cabinet) / IP55 (pump set). Insulation class F.
Applications
- Residential Water Supply: High-rise buildings, villas, hotels — zoned supply with multi-pump rotation and low-noise night sleep mode (≤ 65 dB(A)).
- Commercial & Public Facilities: Office towers, hospitals, schools, sports venues — intelligent matching of normal daily operation and peak holiday demand schedules.
- Industrial Process Water: Cooling water circulation, boiler feed water, cleaning equipment boost — 24-hour continuous operation with full stainless steel wetted parts.
- Agriculture & Irrigation: Greenhouse drip irrigation, field sprinkler systems, aquaculture water supply — variable frequency constant pressure precisely matches crop water curves, saving 30%+ water and energy.
Compliance & Certifications
- Drinking Water Hygiene: SUS304/316L food-grade stainless steel, compliant with GB 5749-2022 Drinking Water Health Standard and CJ/T 254 industry specification.
- Electrical Safety: CCC / CE / UL certified. GB/T 7251.1 low-voltage switchgear standard, EMC Class A industrial requirement.
- Quality Management: ISO 9001:2015 certified. CE/PED 2014/68/EU pressure equipment directive for pressure boundary components.
- Factory Testing: 1.5× rated pressure static test (5 min hold) + PID dynamic pressure verification (≤ ±0.01 MPa fluctuation) + 24-hour water-hammer-free continuous run test.
Installation Guidelines
Confirm foundation flatness ≤ 2 mm/m, reserve ≥ 500 mm clearance on all sides for maintenance and ventilation. Mount the unit on adjustable vibration isolation pads — never rigid grouting. Use flexible rubber joints or stainless steel bellows for inlet/outlet connections with independent pipe supports. Set diaphragm tank pre-charge pressure to 70%–80% of target system pressure. After electrical connection verification, test pump rotation direction and set VFD start/stop thresholds with sleep delay parameters.
Chaodun Pump — professional pump manufacturer providing integrated water supply and variable frequency control solutions for commercial, industrial, and municipal applications worldwide. Contact our technical team for complete dimension drawings, electrical wiring diagrams, and commissioning documentation.