D*1FP servo valves enhance large hydraulic systems

Parker Hannifin has brought out the D*1FP range of pilot-operated servo proportional valves.

These are based on the company's direct-operated DFplus hydraulics control valve, which features Parker's Voice Coil Drive (VCD) technology.

The control behaviour of the Parker Hannifin D*1FP series valves ensures high stability in operation and easy, time-saving installation and set-up.

The VCD is based on the same principle used to vibrate loudspeaker diaphragms.
Parker is using it to control the high forces within hydraulic valves.
By producing dynamics on a par with modern servo valves, the VCD technology results in a much simpler valve structure.
The new pilot-operated D*1FP series has transferred the advantages of the VCD to larger frame sizes and higher flow-rate valves.
The high dynamics and precision of each new pilot valve deliver optimum control of the main spool, resulting in servo-class performance from the complete valve.
The control behaviour of the valves ensures high stability in operation and easy, time-saving installation and set-up.
Whether in the direct or pilot-operated valves, the VCD technology offers the same benefits of robust design and long life.
A new safety concept with the pilot valve can also reduce the need for additional shut-off valves in hydraulics systems.
It ensures the main stage is hydraulically balanced at power down and the main spool is in a safe position.
The D*1FP range is available in four sizes: NG10 (CETOP05), NG16 (CETOP07), NG25 (CETOP08) and NG32 (CETOP10).
With flow rates of up to 3000 litres a minute, the valves bring the advantages of VCD technology to almost any size of hydraulics system and are supported around the world by Parker's global network of manufacturing, sales and customer-support centres.
http://www.manufacturingtalk.com/news/pab/pab311.html

Australian Brake Controls’ air/hydraulic brakes keep tractors and trailers controlled

A CONTRACTOR from Mel-Ray Industries has installed a dual-line air/hydraulic braking system from Australian Brake Controls in his tractors and trailers.

According to Ray Galdes, towing a heavy trailer around worksites can be a potentially hazardous, high maintenance undertaking.

Trucks, tractors and specialized machinery can be subjected to loads that will place unusual stresses on standard components, including high demands on braking systems in situations where operators need to selectively and powerfully apply stopping and holding power.

Examples include going down a one-in-four slope with a 90-degree turn at the bottom. Gravity will see the trailer trying to push straight ahead, off the road. Galdes says he helped increase the responsiveness and control over the vehicles with the Australian Brake Controls system.

His latest system enables the driver to simultaneously control both the tractor’s hydraulic brakes and trailer’s air brakes from the same brake pedal. The operator can also operate the trailer brakes separately using an in-cab hand control.

Galdes says air brakes are the most effective, as other types of brakes get burned out quickly on slopes.

Australian Brake Controls engineered a system which incorporates a tractor-mounted half horsepower electric compressor feeding a nine litre pneumatic holding tank linked by airlines to the trailer brakes.

This pneumatic system is synchronized with the tractor’s hydraulic system via a reaction valve that automatically senses the amount of pressure being applied to the hydraulic system and turns this into an air signal for the trailer’s air system when the brakes are applied.
http://www.myfen.com.au/Article/Australian-Brake-Controls-air-hydraulic-brakes-keep-tractors-and-trailers-controlled/512696.aspx