Bypass valves

Function and installation

HDS bypass valves open as soon as the water pressure reaches a level defined by means of the force of the installed spring.

The more water flows, the wider the valve opens. The excess water is diverted past the main pipe with the device (pump or turbine), where the pressure and flow rate remain constant.

HDS bypass valves are installed in the flow direction.

Quality features

The guide on both sides ensures high plunger stability in all positions, thereby preventing natural oscillations and noise problems.
The plunger's geometric design provides for almost constant pressure loss over wide flow rate ranges while significantly reducing the level of inherent noise.
Integral flushing openings protect the bypass valve from contamination of the guide area.
HDS valves are designed to be robust and compact. They are made from standard POM material and are approved for use in drinking water applications in accordance with KTW and WRAS standards.
Difference to › check valves (backflow preventers): In HDS valves, the plunger opens dynamically with the increased water pressure and keeps the pressure loss at a constant level across wide flow rate ranges. Reliable leakage-free backflow prevention is not required here, so HDS valves have no seal between plunger and housing. In contrast, a check valve reliably prevents backflow and keeps the pressure loss low.

Function and installation

HDS bypass valves open as soon as the water pressure reaches a level defined by means of the force of the installed spring.

The more water flows, the wider the valve opens. The excess water is diverted past the main pipe with the device (pump or turbine), where the pressure and flow rate remain constant.

HDS bypass valves are installed in the flow direction.

Selection criteria

Please note that bypass valves are only available for our OEM / manufacturing customers. For more details, as well as information on worldwide approvals, please see the product listing. To refine your selection, please use the following points as filters.

Mounting bore: HDS bypass valves are available with bore diameters of 15 mm and 20 mm (0.59 and 0.79 inches) as well as springs with varying stiffness for specifying the pressure loss.
Operating temperature: The maximum operating temperature is 65 °C (149° F), with peaks of 90 °C (194° F) within a period of up to 60 minutes.
Differential pressure: For the different sizes, different levels of differential pressure are possible within the indicated range of 50 – 600 mbar. You can access PDFs with flow rate diagrams for the HDS 15 and the HDS 20 right below this section.

Do you need help choosing? You will find the relevant contact information towards the bottom of the page.

HDS 15 flow rate diagram | pdf | 419.08KB

HDS 20 flow rate diagram | pdf | 418.72KB

Get advice now

Please contact us for help finding the right bypass valve. Neoperl offers you solutions that are completely tailored to your requirements. Our qualified staff will be happy to assist you with any questions you may have.

Quality features

The guide on both sides ensures high plunger stability in all positions, thereby preventing natural oscillations and noise problems.
The plunger's geometric design provides for almost constant pressure loss over wide flow rate ranges while significantly reducing the level of inherent noise.
Integral flushing openings protect the bypass valve from contamination of the guide area.
HDS valves are designed to be robust and compact. They are made from standard POM material and are approved for use in drinking water applications in accordance with KTW and WRAS standards.
Difference to › check valves (backflow preventers): In HDS valves, the plunger opens dynamically with the increased water pressure and keeps the pressure loss at a constant level across wide flow rate ranges. Reliable leakage-free backflow prevention is not required here, so HDS valves have no seal between plunger and housing. In contrast, a check valve reliably prevents backflow and keeps the pressure loss low.

Selection criteria

Mounting bore: HDS bypass valves are available with bore diameters of 15 mm and 20 mm (0.59 and 0.79 inches) as well as springs with varying stiffness for specifying the pressure loss.
Operating temperature: The maximum operating temperature is 65 °C (149° F), with peaks of 90 °C (194° F) within a period of up to 60 minutes.
Differential pressure: For the different sizes, different levels of differential pressure are possible within the indicated range of 50 – 600 mbar. You can access PDFs with flow rate diagrams for the HDS 15 and the HDS 20 right below this section.

Do you need help choosing? You will find the relevant contact information towards the bottom of the page.

HDS 15 flow rate diagram | pdf | 419.08KB

HDS 20 flow rate diagram | pdf | 418.72KB

Bypass valves

There are two application areas by way of example:

In water-driven mini-turbines of touchless faucets

In hydraulic assemblies of boilers

Function and installation

Bypass valves

There are two application areas by way of example:

In water-driven mini-turbines of touchless faucets

In hydraulic assemblies of boilers

Quality features

Function and installation

HDS closed

HDS partly open

HDS fully open

Selection criteria

Get advice now

OEM / manufacturers

You might also be interested in

Backflow preventers

Products

Quality features

HDS closed

HDS partly open

HDS fully open

Selection criteria

Get advice now

OEM / manufacturers

You might also be interested in

Backflow preventers

Products