Cranes lift heavy loads, and precise control of the lifting process is paramount for safety and efficiency. Proportional valves fine-tune the hydraulic pressure applied to the lifting mechanism so that operators can control speed and force while lifting and lowering.
In 2021, Australian crane manufacturer Franna sought to improve the performance of its MAC 25 pick-and-carry crane by replacing its main control valve. The MAC 25 mobile articulated crane features a maximum lifting capacity of 27 tons (25 tonnes) and a maximum boom length of 60 ft (18.4 m). The company partnered with Danfoss Power Solutions and selected the PVG 48 proportional valve as the heart of the work and steering subsystems. Danfoss launched the PVG 48 valve to the general market in June 2023, with Franna as a key pilot customer. On the MAC 25, the valve turns operator joystick inputs into quick, accurate boom movement.
PVG 48 is a pre-compensated proportional control valve for applications requiring flow rates up to 47.6 gpm (180 lpm). This latest PVG load-sensing valve is suitable for machines such as wheel loaders, aerial lifts, and cranes in which precise flow and controllability are essential.
“The PVG is extremely precise and reliable. It does what you want it to do repeatedly,” said Adam Murchie, project engineer at Franna. “It’s the ideal choice for MAC 25 and likely to end up in other of our cranes, too — not least in future launches where more advanced electronic controls are key. We wanted a future-proof valve. PVG 48 is it.”
The PVG 48 valve integrates easily with electric actuators, sensors, and digital controls, opening various possibilities. One of them is to automate certain machine functions so the crane assists or even takes over from the operator. Such a function can be advantageous in many situations, particularly when instant reaction is required to ensure safety.
With the change to PVG 48, Franna also switched to Danfoss counterbalance valves. Together with PVG 48, they ensure smooth and safe activation of the crane’s boom.
“Controllability is smooth and even — very refined,” said Quentin Bourke, product support technician at Franna. “The initial tiny bounce on the front tires, which you sometimes see when operators raise or lower the boom, is completely gone. Extension or subtraction of the boom is impressively smooth, too.”
Bourke added that initial feedback from crane operators using MAC 25 with a PVG 48 and Danfoss counterbalance valves is positive, too.
The Danfoss PVG 48 proportional valve is already at work in more than 100 of Franna’s MAC 25 cranes throughout Australia.
Danfoss
danfoss.com
