Danfoss 003Z1335 1-1/4″ AB-QM Pressure Independent Control Valve, 3.5–17.5 GPM

Description

The Danfoss 003Z1335 is a 1-1/4″ AB-QM Pressure Independent Characterized Control Valve (PICC) designed for hydronic heating and cooling systems where precise, stable flow control is critical. By combining differential pressure regulation and flow-limiting functions into a single compact valve body, the AB-QM eliminates the need for separate balancing valves and simplifies system commissioning.

With a flow range of 3.5 to 17.5 GPM, this valve maintains consistent flow regardless of pressure fluctuations across the system, ensuring optimal coil performance, energy efficiency, and occupant comfort. It is an ideal solution for variable flow distribution systems in commercial HVAC applications including fan coil units, air handling units, and chilled beam systems.

Key Features

• Pressure independent operation — combines balancing and control in one valve
• 1-1/4″ pipe connection for versatile installation
• Flow range: 3.5 to 17.5 GPM
• Eliminates the need for separate differential pressure controllers
• Characterized control characteristic for accurate flow regulation across the full stroke
• Compatible with Danfoss electric actuators for automated control
• Compact, single-body design simplifies installation and reduces piping complexity
• Suitable for both heating and cooling hydronic applications

Applications

• Commercial fan coil units
• Air handling units (AHUs)
• Chilled beam and radiant systems
• Variable flow hydronic distribution systems
• Building automation and energy management systems

Why Choose the Danfoss AB-QM?

The AB-QM series is a trusted solution among mechanical contractors and engineers for its ability to dramatically reduce balancing time and improve system accuracy. By maintaining a set flow rate independent of differential pressure variations, it protects coils from over- or under-flow conditions, extends equipment life, and supports energy savings in variable speed pump systems. The Danfoss 003Z1335 is built to perform reliably in demanding commercial HVAC environments.