QD / QD(G) / HORIZONTAL
High-head water and boiler-feed review
A horizontal multistage pump-and-drive arrangement. Start with the applicable version when the project includes boiler feed or hot-water duty.
Multistage Centrifugal Pumps
Horizontal and vertical pumps for high-head water duties.
Compare horizontal and vertical multistage centrifugal pumps for high-head water transfer, boiler feed and pressure boosting. Review QD(G) and QDL/QDLS against the required duty, liquid temperature and inlet supply.
Horizontal or vertical multistage?
Compare the assembly layout and liquid duty before selecting the model and stage arrangement.
QDL / QDLS / VERTICAL
Clean-water boosting and treatment
A non-self-priming vertical multistage arrangement. Review the inlet supply, assembly height and liquid suitability for the proposed duty.
Compare horizontal and vertical multistage pumps
QD(G) covers horizontal high-head and boiler-feed duties; QDL/QDLS offers a vertical arrangement for boosting and water treatment. Check the applicable version and water temperature.
QD(G)
QD(G) Horizontal Multistage Boiler-Feed Pump
QD(G) uses a horizontal multistage arrangement for high-head water transfer and boiler-feed duties. The water-temperature limits depend on the version and its model data.
- boiler feed
- hot-water transfer
- high-pressure water transfer
QDL/QDLS
QDL/QDLS Vertical Multistage Pump
QDL/QDLS is a non-self-priming vertical multistage pump for boosting and water treatment. Its stacked arrangement provides a different installation layout from a horizontal multistage pump.
- building water supply
- industrial boosting
- water treatment
Compare horizontal and vertical multistage pumps
Use this guide to compare the arrangement and information required for selection. Confirm the actual model curve and operating limits for your duty.
Swipe across the table to compare all columns.
| Installation & duty | QD / QD(G) horizontal | QDL / QDLS vertical |
|---|---|---|
| Assembly layout | Horizontal multistage pump and drive arrangement. | Vertical multistage pump with motor above the stages. |
| Application direction | High-head water transfer and applicable boiler-feed duties. | Water boosting, treatment and irrigation. |
| Hot-water selection | Confirm the actual QD / QD(G) version and its temperature limit. | Check the actual model temperature and liquid limits; do not assume boiler-feed suitability. |
| Installation space | Review the base, alignment, connections and access along the assembly. | Review vertical clearance, pipe connections and motor removal access. |
| Inlet condition | Review suction conditions at the actual operating temperature. | Non-self-priming; confirm a suitable inlet supply and filling arrangement. |
| Operating range | Select from the actual curve, speed and stage configuration. | Select from the actual curve, speed and stage configuration. |
Plan the assembly around installation and service
The selected curve, mechanical version and arrangement drawing should describe the same proposed pump.
01
Stages and duty
Use the model curve to match flow and head together. Confirm the proposed stage arrangement, speed and motor against the complete operating range.
02
Temperature and materials
For hot-water duties, review the actual version, seal arrangement and wetted materials. Keep temperature and inlet conditions together when assessing suitability.
03
Access and interfaces
Allow for the horizontal base and drive or the vertical assembly height. Check connections, pipe support, lifting access and the space needed for maintenance.
Applications for multistage pumps
Boiler feed and process heating
Review feedwater temperature, tank conditions, delivery duty and low-flow provisions together for the applicable pump version.
Clean-water pressure boosting
Compare the pressure increase and demand range, then coordinate the selected pump with controls and the delivery network.
Water transfer and irrigation
Keep required flow, delivery elevation, pipe losses and water quality in the same duty description.
Head, temperature and inlet supply
High-head transfer, pressure boosting and boiler feed impose different conditions on the pump. Water temperature and inlet supply belong with the required flow and head.
- Required flow and total head
- Water temperature and composition
- Inlet supply, including available suction data
- Continuous or intermittent operation
- Installation space and power supply
Define the equipment you need included
Agree the pump version, drive and arrangement first. Identify the controls and plant-system provisions needed around that assembly.
01
Pump, motor and installation
Series and model, speed, motor, materials, seal arrangement, connections and mounting. Request the selected curve and arrangement drawing for the proposed configuration.
02
Control and plant provisions
Duty control, standby operation, instruments and any required low-flow provision. Clarify return pipework, valves, electrical interfaces and items provided by the plant.
Technical documents
Industrial pump brochure
The industrial pump brochure introduces QD / QD(G) and QDL / QDLS. Request the proposed model curve, temperature limits, arrangement drawing and operating instructions for the final equipment review.
Multistage Pumps questions
Does a multistage pump automatically suit boiler feed?
No. Boiler-feed suitability depends on the actual series, version, temperature limits, materials, sealing and inlet conditions. Review those details for the proposed equipment.
How should I compare horizontal and vertical multistage centrifugal pumps?
Use the same required flow, head and liquid conditions. Compare the model curves and then review installation space, inlet supply, connections and service access.
Can I select a pump from maximum head?
A maximum head value alone is insufficient. Selection requires the flow and head together on the applicable model curve, with the correct speed and configuration.
Why provide the minimum operating flow?
The selected pump has an operating range. Minimum demand helps establish whether a control or minimum-flow provision is needed and how it should be arranged.
Which documents should accompany a proposal?
Request the proposed curve, assembly drawing, motor data, applicable liquid and temperature limits, operating instructions and the inspection documents agreed for the order.
Related pump families
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- Application and liquid
- Pump, drive and installation
- Curves, drawings and document scope