QHYB-GDL Variable Frequency Water Supply Equipment

QHYB-GDL Variable Frequency Water Supply Equipment

QHYB-GDL Domestic VFD Constant-Pressure Unit | Packaged booster for stable building supply

  • VFD constant-pressure: Stable pressure under variable demand.
  • GDL multistage pump set: Compact inline boosting.
  • Multi-pump control: Staging/alternation for duty matching.
  • Protection & alarms: Dry-run/low-pressure + overpressure with status signals.
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Product Overview

The QHYB-GDL VFD Domestic Water Supply Unit (equipped with a GDL vertical in-line multistage centrifugal pump) is a tankless packaged water supply system consisting of a pump unit, an automatic control system, and a pressurization & pressure-stabilizing device. The water supply capacity is determined by the pump configuration, while coordinated operation is managed by the control system. The pressurization and pressure-stabilizing device stores energy and maintains pipeline pressure to compensate for low-flow demand and normal pipeline leakage. When water demand increases and pipeline pressure drops, the system automatically starts the pump(s) to restore the supply pressure.

Model Designation

QHYB GDL Variable Frequency Water Supply Equipment type

Key Features

  • Tankless packaged configuration with high system integration for turnkey installation

  • Two operating modes available: pneumatic pressure-stabilized mode and VFD (variable frequency drive) mode

  • Multi-pump parallel operation (1–4 pumps or more) to match required design flow and total head

  • Low-flow operation handled by the pressure-stabilizing device / auxiliary pump(s), reducing main pump start-stop frequency and lowering energy consumption

Engineering Summary

The QHYB-GDL packaged water supply unit uses a multistage centrifugal pump as the core supply equipment, with pump operation automatically regulated by an integrated control system. Depending on operating requirements, the unit can be configured as a pneumatic pressure-stabilized supply unit or a VFD supply unit, each with distinct pressure-maintenance and energy-consumption characteristics. Based on the required design flow and total head, 1–4 pumps (or more) can be arranged for parallel operation. Under low-flow conditions, the main pump works in coordination with an auxiliary pressurization and pressure-stabilizing pump set to improve overall efficiency and reduce total energy consumption.

Typical Applications

The QHYB-GDL unit is widely used in:

  • Domestic and residential water supply systems

  • Industrial water supply systems

  • Firefighting and sprinkler supply systems

  • Irrigation and related water supply applications

It supports both continuous-demand applications (e.g., hotels, catering facilities, industrial and mining enterprises) and intermittent-demand applications (e.g., office buildings, commercial and residential buildings, and certain process water systems), while accommodating seasonal and regional variations in water consumption.

System Configuration

The unit is a packaged, integrated system. The core configuration consists of a multistage centrifugal pump supply unit (main pump and optional auxiliary pump), an automatic control system, and a pressurization & pressure-stabilizing device, with associated piping connections and packaged integration components. Under normal operation, low-flow demand and leakage compensation are handled by the pressure-stabilizing device / auxiliary pump(s), reducing unnecessary main pump cycling and extending service life of critical components.

Components & Supply Scope

The QHYB-GDL VFD packaged water supply unit mainly includes:

  • Multistage centrifugal pump supply unit (main pump and optional auxiliary pump)

  • Automatic control system

  • Pressurization and pressure-stabilizing device

  • Piping connections and packaged integration components

Technical Service

The packaged, highly integrated design simplifies onsite installation and commissioning. During normal operation, low-flow demand and leakage compensation are handled by the pressure-stabilizing device / auxiliary pump(s), which reduces frequent main-pump cycling, minimizes mechanical wear, and extends pump service life. The control system provides automatic operation management, reducing the need for manual intervention.

Operating Conditions

System selection should be based on the following engineering parameters:

  • Design water supply flow rate

  • Required supply pressure (total head)

  • Demand variation pattern (continuous or intermittent)

  • Time-dependent and seasonal demand fluctuations

  • Region- and application-specific water-use characteristics

Service Conditions

For fire sprinkler systems, a pneumatic pressure-stabilized supply configuration is generally recommended, and an auxiliary low-flow pump may be configured to compensate for pipeline leakage, supporting long-term pressure-maintenance operation.

Protection Functions

  • Integrated water supply and pressure stabilization with a high level of automation, providing compensation for low demand and normal leakage

  • VFD mode enables constant-pressure supply; typical pressure control accuracy ≤ 0.02 MPa

  • Compared with conventional pneumatic systems, VFD operation delivers an average energy saving of about 20%

  • VFD soft-start reduces inrush current and mechanical shock, and lowers noise during low-speed operation

  • Pneumatic mode offers lower initial investment with simpler control logic and maintenance requirements

Selection Criteria

Selection should be determined based on design flow rate and total head, combined with the demand profile (continuous/intermittent), time-slot and seasonal fluctuations, and regional/application water-use characteristics. For fire sprinkler duty, pneumatic pressure-stabilized configuration is generally preferred; where necessary, an auxiliary low-flow pump should be configured for leakage compensation to avoid unnecessary main-pump starts.

Specifications & Installation

Selection Guide

I. Pump Selection for Water Supply Units

1. Selection of water supply height for variable-frequency constant-pressure water supply units
Unit head (m)
20
26
32
40
50
60
70
80
100
120
Water supply height (m)
10
14
18
25
32
38
46
55
72
88

 

2. Selection of number of households served by variable-frequency constant-pressure water supply units
Unit flow rate (m³/h)
6
12
18
25
36
50
Number of households served
20–30
40–60
60–100
100–150
150–200
200–300

 

Unit flow rate (m³/h)
75
100
150
200
250
Number of households served
400–500
600–1000
1000–1500
1500–2000
2000–3000

Performance Parameters

Applicable Building
Sprinkler flow rate
(L/s)
Operating pressure
at sprinkler head
(MPa)
Applicable building height
(m)
Recommended water supply unit model
Vertical pump set
Building type
Design density
(L/min·m²)
Coverage area
(m²)
Production building
10
300
60
0.1
≤12
QHYB60-0.24-125GDL-3
Production building
10
300
60
0.1
≤24
QHYB60-0.4-125GDL-3
Production building
10
300
60
0.1
≤36
QHYB60-0.6-125GDL-3
Production building
10
300
60
0.1
≤50
QHYB60-0.8-125GDL-3
Production building
10
300
60
0.1
≤72
QHYB60-1.0-125GDL-3
Production building
10
300
60
0.1
≤100
QHYB60-1.2-125GDL-3
Storage building
15
300
90
0.1
≤12
QHYB90-0.24-150CDL-3
Storage building
15
300
90
0.1
≤24
QHYB90-0.4-150CDL-3
Storage building
15
300
90
0.1
≤36
QHYB90-0.6-150CDL-3
Storage building
15
300
90
0.1
≤50
QHYB90-0.8-150CDL-3
Storage building
15
300
90
0.1
≤72
QHYB90-1.0-150CDL-3
Storage building
15
300
90
0.1
≤100
QHYB90-1.2-150CDL-3
Ordinary hazard
6
300
40
0.1
≤12
QHYB40-0.24-100CDL-3
Ordinary hazard
6
300
40
0.1
≤24
QHYB40-0.4-100CDL-3
Ordinary hazard
6
300
40
0.1
≤36
QHYB40-0.6-100CDL-3
Ordinary hazard
6
300
40
0.1
≤50
QHYB40-0.8-100CDL-3
Ordinary hazard
6
300
40
0.1
≤72
QHYB40-1.0-100CDL-3
Ordinary hazard
6
300
40
0.1
≤100
QHYB40-1.2-100CDL-3
Light hazard
3
300
15
0.1
≤12
QHYB15-0.24-65GDL-3
Light hazard
3
300
15
0.1
≤24
QHYB15-0.4-65GDL-3
Light hazard
3
300
15
0.1
≤36
QHYB15-0.6-65GDL-3
Light hazard
3
300
15
0.1
≤50
QHYB15-0.8-65GDL-3
Light hazard
3
300
15
0.1
≤72
QHYB15-1.0-65GDL-3
Light hazard
3
300
15
0.1
≤100
QHYB15-1.2-65GDL-3
Users can select appropriate models according to the parameters provided.

OEM & Custom

Chaodun Pump offers OEM and ODM customization for QHYB-GDL systems, including pump selection, control configuration, pressure tank sizing, and material customization for residential, industrial, or municipal water systems.

FAQs

  1. Q1: What is the QHYB-GDL system used for?
    It provides automatic constant pressure water supply for domestic, industrial, and fire protection systems.
  2. Q2: What type of pump is used?
    It uses GDL vertical inline multistage centrifugal pumps.
  3. Q3: What are the main advantages?
    Energy saving, low noise, compact design, and automatic control.
  4. Q4: Can it handle variable flow rates?
    Yes, the system automatically adjusts speed and pressure.
  5. Q5: Is it suitable for firefighting?
    Yes, it supports firefighting and sprinkler systems with stable pressure output.
  6. Q6: What materials are used?
    High-grade stainless steel and corrosion-resistant alloys for durability.
  7. Q7: Does Chaodun Pump provide OEM customization?
    Yes, complete OEM and ODM customization services are available.