Four-way straight valve Herz VUA 40 1/2" (model 1 7783 41) — hydraulic balancing and mixing valve

Herz VUA 40 1/2" (model 1 7783 41) is a four-way straight valve designed for hydraulic balancing and mixing in heating and cooling systems. The valve connects supply and return circuits with 1/2" threaded connections and enables controlled redirection of flow between primary and secondary loops. It is intended for use where mixing, temperature regulation and circuit separation are required, such as radiator circuits, underfloor heating manifolds, boiler bypass lines and system commissioning tasks.

Advantages

The valve offers compact four-way functionality in a straight-body design that simplifies piping layouts and reduces the need for additional fittings. It supports precise hydraulic balancing and stable mixing behaviour across typical residential and light commercial installations. The construction ensures reliable operation in both heating and cooling modes and allows straightforward integration with existing manifolds and circuits that use 1/2" threaded connections.

Suitable for

• Mixing primary and secondary circuits in radiator and underfloor heating systems
• Boiler bypass and temperature stabilisation in small to medium installations
• Commissioning and balancing of heating/cooling loops
• Separation of supply and return lines where controlled flow direction is required

Key specifications

• Valve type: four-way straight mixing/balancing valve
• Connection size: 1/2" threaded connections
• Application: hydraulic balancing, mixing, circuit separation in heating and cooling systems
• Suitable media: water-based heat transfer fluids used in HVAC systems
• Installation orientation: inline/straight pipe run integration

How to use

Install the Herz four-way straight valve into the pipe run where mixing or circuit separation is required, ensuring compatibility with 1/2" threaded fittings and correct flow direction according to system design. Use the valve to blend return and supply flows or to bypass part of the primary flow into a secondary loop; adjust associated actuators or balancing elements as needed to achieve the desired temperature and flow distribution. During commissioning, verify hydraulic balance and temperature setpoints, and make fine adjustments to ensure stable operation in both heating and cooling modes.

Usage recommendations

For reliable performance, flush the system before installation, check that fluid quality and inhibitor levels meet HVAC guidelines, and ensure thread sealants or tape compatible with system fluids are used. Refer to system design parameters when integrating the valve, and perform hydraulic balancing and temperature verification after installation to confirm correct function.