The function of directional control valves is to control the movement and direction of hydraulic fluids through a defined system. Also known under the denomination of switching valves, the control valves belong mainly to three main categories: hydraulic check valves, directional spool valves and poppet valves.
Why do you need one? Things you need to consider
Since control valves are key switches within the hydraulic system, there are five major points to consider when analyzing the performance and suitability of directional control valves:
1/ Dynamic Power Limits;
2/ Static Power Limits;
3/ Resistance To Flow;
4/ Switching Time;
5/ Leakage;
Hydraulic check valves: how can I use them?
Check valves are regularly used in hydraulic systems, being the simplest and most common form of directional control valves. These valves can be used to stop the flow of liquid in one direction, at the same time still allowing the free flow of fluid in the opposite direction. These type of control valves are also commonly known as non-return valves.
Hydraulic check valves can also fulfill a range of other roles within a hydraulic system, including:
– Prefill-valves for anti-cavitation;
– Bypass valves or return-line filters;
– Denying flow in one direction;
– Pre-tensioning by creating backpressure within the system;
– Protect hydraulic components against surges in pressures;
Most check valves are spring-loaded and rely on a ball or plate to seal the flow in a single direction. Check valves are designed to be able to reliably isolate circuits without running the risk of leakage. A range of different elements, including poppets with soft seals can also be used within these valves to isolate circuits.
Directional spool valves : how can I use them?
This kind of directional control valves is composed of a moving spool which is situated inside the housing of a valve. An actuating force then moves the control spool, which allows the channels within the housing to be connected or separated.
This type of directional control valves have a range of unique features which makes them suitable for different conditions, including:
1// A low actuating force
2// A high switching power
3// Their simplicity makes them cheap to produce
4// Low-level losses, despite consistent oil leakage
5// A wide range of control functions for operator ease
This type of control valves are very versatile because they can be either directly-operated or pilot-operated. They can be connected with solenoids or mechanically controlled via levers and rollers, or via hydraulic or pneumatic systems.
What about directional poppet valves?
This type of control valves is fit into housing bores with a threaded connection, which is why they are commonly referred to as cartridge valves. These valves are suitable for operating situations of up to 1,000 bar and can contain a range of seating elements, including balls, poppets and plates.
Key features of the directional control valves which makes this model extremely useful:
– No leakage;
– A long and reliable product lifetime;
– High maximum operating capacities;
– Very good sealant characteristics;
Their design allows these valves to become more tightly sealed when the operating pressure increased. Compared to other kinds of control valves, their maximum flow is often limited, making them unsuitable for systems which require high flow rates.
At Hydraulic Center Group, we can provide a diverse range of valves, including hydraulic check valves for a diverse range of systems and applications. For more information, please don’t hesitate to get in touch with our professional team of hydraulic specialists today..
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