The Non-Negative Pressure VFD Water Supply Unit directly connects to municipal networks using pressure-stacking technology and VFD control, featuring SUS304/food-grade coated wetted parts for ±0.01 MPa constant-pressure delivery.
It solves excessive footprint, high civil costs, secondary contamination, municipal network negative pressure backflow, and redundant energy consumption in conventional secondary water supply systems with large storage tanks.
It is suitable for residential complexes, commercial buildings, industrial parks, direct drinking water systems, and multi-story zoned distribution requiring direct municipal integration and negative pressure protection.
Extended Service Life: SUS304 food-grade stainless steel wetted parts/841 epoxy coating + branded core electrical components resist corrosion & fatigue. Design lifespan ≥15 years—over 50% longer than traditional tank-based water supply equipment.
Significant Energy Savings: VFD soft-start + constant-pressure PID closed-loop control + municipal residual pressure utilization reduces comprehensive energy consumption by 20%–50%. Combined with intelligent sleep strategy, annual electricity costs drop by 30%–60%.
Lower Maintenance Costs: Integrated skid-mounted base + pipe-disassembly-free maintenance design enables routine inspection without disconnecting main pipes. Single technician completes sensor/filter/pressure checks within 1 hour, reducing O&M costs by 40%+.
Lightweight & Compact Design: Fully enclosed direct-connection structure eliminates underground reservoirs & heavy pump houses. Footprint reduced by 30%+ for equivalent supply ratings, significantly lowering infrastructure investment & room space occupancy.
Faster Installation: Pre-installed quick-connect flanges + integrated bypass/pressure tank layout enable positioning → pipe connection → parameter setting within 2 hours, compressing deployment cycle by 50%.
Residential: Communities/high-rise/villas domestic water | Zero negative pressure | Stable supply |
No secondary contamination
Commercial: Hotels/malls/offices constant-pressure | VFD on-demand flow | 20–50% energy savings | Peak/off-peak adaptive
Industrial: Factory/park production & domestic boosting | Enclosed pipe-network superposition |
Drinking water hygiene compliant Special: Pure water/direct-drinking/zone supply boosting | Bypass + small tank | Pressure stability ≤±0.01 MPa
Media/System: Drinking/pure/non-corrosive liquids | Flow 2.4–300 m³/h | Pressure 0–1.6 MPa | Direct municipal, zero negative pressure
Product Structure Diagram | |
| No. | Material Name |
| 1 | VFD Control Panel |
| 2 | To Domestic Water Network |
| 3 | Bypass Pipe |
| 4 | Pressure Gauge |
| 5 | Electrode Level Transmitter |
| 6 | Vacuum Compensation Air Valve |
| 7 | Municipal Network Water Inlet Available |
| 8 | Pressure Gauge |
Media: Drinking/pure/non-corrosive liquids | Wetted: SUS304 or food-grade 841 epoxy System: Flow 2.4–300 m³/h | Pressure 0–1.6 MPa adj. | Accuracy ≤±0.01 MPa | Municipal direct + auto vacuum suppressor
Electrical: VFD + microcomputer constant-pressure | Protection: Overload/short/overvoltage/phase-loss/overheat/stall + soft-start | Logic: On-demand freq. + multi-pump smart rotation
Environment: Vertical/horizontal optional | Indoor dry/ventilated, non-corrosive/non-explosive (custom) | Ref: Media 0–40°C | Ambient ≤40°C | Power 380V/50Hz
Note: Special conditions (high altitude/extreme temp/corrosion/explosion-proof)? Consult before selection. Custom solutions available.
Drinking Water Hygiene Compliance: Strictly manufactured per “Administrative Measures for Hygiene Supervision of Drinking Water” & GB 5749-2022 “Standards for Drinking Water Quality”. Wetted parts passed drinking water safety evaluation with provincial sanitary permits, eliminating secondary contamination risks.
Industry Equipment Certification: Compliant with CJ/T 254-2014 “Non-negative pressure water supply equipment”. Negative-pressure elimination & superposition technology passed testing by National Water Supply & Drainage Equipment Quality Supervision & Inspection Center. Third-party full performance reports available.
International Quality System: ISO 9001:2015 certified. Core electrical components comply with CE/UL certification requirements, meeting EU/US market entry.
Factory Inspection Standard: Every unit undergoes 1.5× rated pressure hydrostatic test (5-min hold) + constant-pressure accuracy test (fluctuation ≤±0.01 MPa) + 24-hour water-hammer-free linkage operation verification, guaranteeing zero-fault delivery.
Fast Standard Delivery: Covers flow 2.4–300 m³/h, pressure 0–1.6 MPa. Standard SUS304 wetted parts + branded VFD + IP54 control cabinet. Technical confirmation within 72 hours.
Deep Customization Capabilities:
Material Upgrade: Wetted parts optional in 316L stainless steel/food-grade epoxy coating for high-chloride or higher hygiene requirements.
Control Expansion: Optional IoT cloud platform, municipal pressure interlock protection, multi-unit master-slave parallel control, auto-start/auto-fill on power failure.
Structural Adaptation: Vertical/horizontal layout switching, flange standard switching (GB/ANSI/DIN), outdoor rain/soundproof canopy, custom bypass pipe sizing.
Special Conditions: Derating for high altitude (>1000m), insulation/cooling for extreme temps (-10℃ to +50℃), electrical protection upgrade for explosion-proof zones.
Please contact us for customization inquiries. Our engineering team delivers process proposals within 48 hours.
Installation Key Points:
1.Mount equipment horizontally on solid foundation. Level using vibration isolators. Ensure flatness ≤2 mm/m. No pre-embedded anchor bolts required.
2.Connect inlet/outlet with flexible rubber joints. Never transmit pipe stress to equipment body. Provide independent supports for bypass piping.
3.Control cabinet junction box faces outward. Separate signal & power cables in conduits. Grounding ≤4 Ω. Pre-charge pressure tank to 70%–80% of system working pressure.
4.Set target pressure (default 0.3–0.6 MPa) & rotation logic via HMI. Confirm vacuum suppressor is free-moving. Open municipal inlet valve before startup.
Commissioning Process: Confirm municipal inlet → Set pressure/parameters → Jog test for direction → Constant-pressure linkage test → Simulate peak/off-peak loads to verify fluctuation ≤±0.01 MPa → Record frequency/pressure/current data → Acceptance sign-off.
Request the “CDWG Non-Negative Pressure VFD Water Supply Equipment Installation & Maintenance Manual” (PDF/English version) for complete dimensional drawings, bypass connection diagrams, and commissioning logs.
Q1: How does pipe-network superposition completely eliminate municipal negative pressure interference?
Uses vacuum suppressor + flow compensator + pressure transmitter for real-time monitoring. When municipal pressure drops below safety threshold, equipment auto-reduces frequency/stops & opens bypass valve, ensuring network pressure always ≥0 MPa.
Q2: How does intelligent VFD achieve constant-pressure fluctuation ≤±0.01 MPa?
0.1-class high-precision pressure sensor + PLC PID algorithm + pressure tank elastic buffering form a 100ms-response closed loop. Tested fluctuation strictly ≤±0.01 MPa, zero perception at terminal outlets.
Q3: How does fully enclosed structure prevent secondary contamination from the source?
Eliminates open tanks. Water flows entirely in SUS304/food-grade epoxy sealed pipes. Dead-zone-free welded structure with periodic auto-flushing completely isolates air, algae & insects.
Q4: How does VFD control achieve 20%–50% energy savings?
Soft-start eliminates water hammer. Auto-reduces speed or enters sleep mode during night/low load. Directly utilizes existing municipal residual pressure of 0.2–0.4 MPa, drastically reducing redundant work.
Q5: How does equipment protect & recover during sudden municipal water outage?
Built-in inlet low-pressure protection cuts output & alarms within 1 second if pressure <0.05 MPa. After municipal supply resumes, system auto-detects达标 pressure, delays 30 seconds, & seamlessly restarts—no manual intervention.
