PDV directional valve system
POWER-HYDRAULIK is extending its product range to include a PDV directional valve system that facilitates continuous and load-independent feedback control of the volumetric flow rates of several consumers, and which can be mounted either as a standalone unit or in combination with other monobloc units. This valve system is based on a modular disk design and comprises an input section with integrated pressure relief and recirculating valves, as well as with the additional option of various safety valves.
The consumer modules include a main piston and an individual pressure balance for precision and load-independent feedback control. As an option, the working sections can be equipped with shock valves and suction extractor units. With the types of actuation available - manual, electrohydraulic, with or without internal feedback - a broad range of applications can be covered.
The individual consumer modules are all capable of 'load-sensing' - the highest level of pressure occurring in the system is directed to the inlet section via integrated non-return valves where it is then available to serve the energy-saving closed-loop flow controller. This 'closed-center' design of direction valve enables the valve system to be operated by either a constant displacement pump or by a variable displacement pump. As an option, input sections can also be obtained with locking inlet pressure scales to enable the system to switch between these two types of pump.
The construction of this PDV unit is designed to allow the cost-effective manufacture of short to medium-volume production runs, and the valves can also be employed in mobile applications, e.g. wheel loaders as well as agricultural and municipal vehicles.