The VFD Constant Pressure Water Supply Unit integrates PID control, VFD soft-start, and diaphragm pressure tank for ±0.01 MPa precision constant-pressure delivery at -15℃ to +120℃ with 1.6/2.5 MPa rating.
It solves excessive footprint, high civil costs, pressure fluctuation/water hammer, and secondary contamination in conventional secondary water supply systems dependent on elevated tanks or large reservoirs.
It is suitable for high-rise/villa domestic water, commercial building boosting, industrial cooling circulation, and agricultural irrigation requiring tankless design, fully automatic unattended operation, and low-maintenance performance.
Extended Service Life: SUS304/316L stainless steel wetted parts + silicon carbide dual mechanical seals resist wear, corrosion & cavitation. Design lifespan ≥15 years—over 40% longer than traditional cast-iron pump + tank solutions.
Significant Energy Savings: PID closed-loop on-demand frequency regulation + VFD soft-start eliminates startup/shutdown impact. Comprehensive energy savings 20%–50% at rated duty. Combined with intelligent sleep strategy, annual electricity costs drop by 30%–60%.
Lower Maintenance Costs: Integrated standard base + quick-connect interface layout enables routine inspection without disconnecting main pipes. Single technician completes pressure tank check/sensor calibration within 1 hour, reducing O&M costs by 45%.
Lightweight & Compact Design: Eliminates underground reservoirs & independent pump houses. Pump + control cabinet + pressure tank highly integrated. Footprint reduced by 60%+ for equivalent supply ratings, significantly lowering infrastructure investment & room space occupancy.
Faster Installation: Pre-assembled coupling base + factory pre-wired. Positioning → pipe connection → parameter setting within 2 hours. Deployment cycle compressed by 50%, plug & play ready.
Building Domestic Water: Zone water supply for high-rise residences/villas/hotels, eliminating pressure fluctuation, ensuring terminal experience, supporting multi-pump rotation & night quiet sleep mode.
Commercial & Public Facilities: Water systems for offices/hospitals/schools/venues, quiet operation (≤65 dB(A)), intelligently adapting to daily off-peak & holiday peak dual conditions.
Industrial Process Water: Cooling water circulation, boiler make-up, cleaning equipment boosting. SUS304/316L full stainless steel wetted parts resist corrosion, meeting 24/7 continuous production demands.
Agriculture & Irrigation: Greenhouse drip irrigation, farmland sprinkler, aquaculture water supply. VFD constant pressure precisely matches crop water curves, avoiding pipe pressure surge, saving water & energy by 30%+.
Media Compatibility: Clean water or non-corrosive liquids with similar properties. Solid content ≤0.1% (vol), no long fibers. Temperature: -15℃ to +120℃ (5℉ to 248℉).
Media: Clean water or similar non-corrosive liquids | Solids ≤0.1% vol, no long fibers Temp: Media -15°C to +120°C (standard/high-temp optional) | Ambient 0–40°C (32–104°F) | Humidity ≤95% non-condensing
System: Max pressure 1.6/2.5 MPa (232/363 psi, per configuration) | Constant-pressure accuracy ≤±0.01 MPa (±1.45 psi) | Control: PID closed-loop stepless regulation + multi-pump parallel operation
Electrical: Power 3-phase 380V±10%/50Hz (customizable 60Hz/other voltage) | Protection: Cabinet IP54 / Pump set IP55 | Insulation: Class F
Note: Special conditions (high altitude/extreme temp/strong corrosion/explosion-proof)? Consult before selection. Custom solutions available.
Drinking Water Hygiene Compliance: Wetted parts in SUS304/316L food-grade stainless steel, passed drinking water safety evaluation, compliant with GB 5749-2022 “Standards for Drinking Water Quality” & CJ/T 254 industry norms, eliminating secondary contamination from the source.
Electrical Safety Certification: VFD control cabinet & core electrical components certified with CCC/CE/UL, compliant with GB/T 7251.1 “Low-voltage switchgear assemblies”, EMC meets Class A industrial requirements.
International Quality System: ISO 9001:2015 certified. Pressure boundary parts evaluated per CE/PED 2014/68/EU, supporting EU/US market entry.
Factory Inspection Standard: Every unit undergoes 1.5× rated pressure hydrostatic test (5-min hold) + dynamic PID constant-pressure verification (fluctuation ≤±0.01 MPa) + 24-hour water-hammer-free continuous run test, guaranteeing zero-fault delivery.
Fast Standard Delivery: Covers flow 2–300 m³/h, head 20–200 m. Standard SUS304/316L SS + IP55 motor + branded VFD. Technical confirmation within 72 hours.
Deep Customization Capabilities:
Material Upgrade: Wetted parts optional in 2205 duplex steel/special alloys for high-chloride or ultra-pure hygienic conditions.
Control Expansion: Optional IoT cloud platform, municipal pressure feed-forward linkage, auto-protection/auto-fill on power failure, multi-station cluster dispatch system.
Structural Adaptation: Vertical/horizontal base switching, flange standard switching (GB/ANSI/DIN), outdoor rain/soundproof canopy.
Special Conditions: High-temp (≤120℃) cooling/seal upgrade, VFD derating & forced air cooling for high altitude (>1000m), explosion-proof Ex d certification.
Please contact us for customization inquiries. Our engineering team delivers process proposals within 48 hours.
Installation Key Points:
1.Mount unit horizontally on solid foundation. Level using adjustable vibration pads (flatness ≤2 mm/m). Never use rigid grouting to avoid vibration transmission.
2.Connect inlet/outlet with flexible rubber joints or stainless steel bellows. Provide independent pipe supports. Never transfer pipe weight/thermal stress to unit interfaces.
3.Keep control cabinet back wall ≥150 mm from wall for heat dissipation. Separate power & signal cables in trays. Pre-charge pressure tank to 70%–80% of target system pressure.
4.Open vent valve to exhaust air. Jog test pump rotation (confirm no abnormal friction). Set VFD start/stop pressure thresholds & sleep delay parameters.
Commissioning Process: Electrical wiring verification → Pressure/parameter setting → Single pump jog rotation → Constant-pressure linkage test (simulate peak/off-peak) → Record frequency/pressure/current/temp data → Acceptance sign-off.
Request the “Vertical Multi-Stage VFD Constant-Pressure Water Supply Unit Installation & Maintenance Manual” (PDF/English version) for complete dimensional drawings, electrical schematics, and commissioning logs.
Q1: How does PID closed-loop control achieve constant-pressure fluctuation ≤±0.01 MPa?
Uses 0.1-class high-precision pressure transmitter (sampling ≤100ms) + PLC digital PID algorithm + VFD vector frequency regulation, combined with pressure tank elastic buffering for millisecond-response closed loop. Tested fluctuation ≤±0.01 MPa.
Q2: How does VFD soft-start prevent water hammer & extend pipe life?
VFD controls smooth motor acceleration (0→50Hz in 3–10s), eliminating hydraulic shock from direct line-frequency start. Frequency ramps down during stop. Combined with check valve & pressure tank relief, pressure change rate ≤0.05 MPa/s, completely eliminating water hammer.
Q3: How do dry-run/phase-loss/overheat protections trigger auto-shutdown?
Control cabinet integrates water shortage sensor (inlet pressure <0.05 MPa triggers), phase sequence monitor, & PTC thermistor. Fault signals processed by PLC cut output within 1 second & trigger audio-visual alarm, preventing motor burnout.
Q4: How do stainless steel wetted parts prevent secondary contamination from the source?
Fully welded SUS304/316L passages with no dead zones, electropolished inner walls (Ra ≤0.8 μm). Eliminates open tanks. Water circulates entirely sealed, completely isolating air contact & algae/bacteria growth, complying with food-grade hygiene certification.
Q5: What customizations are needed for high-temperature variant (>80℃)?
Standard suits -15℃ to +80℃. For >80℃: ① FKM/PTFE high-temp seals; ② Pump body insulation jacket & independent forced motor cooling; ③ VFD derating & dedicated control cabinet cooling air duct design.
