Manifolds are primarily used in hydraulic power systems to control the flow of oil through a particular circuit to supply power to and from an actuator. They are used in both industrial and mobile applications. Like a switchboard in an electrical circuit, manifolds are considered the hub of any fluid power system sending fluid to particular equipment at a particular time. Customization, space claim, weight, efficiency, and simplification are all reasons why manifolds are used.
Three styles of functional components are available for integrated manifolds:
There are many different types of mechanical and electro-mechanical valve cartridges available. They range from pressure control (pressure reducing & pressure relief), check valves (piloted & non piloted), flow control (pressure compensated & non-pressure compensated), unloading, sequence, and counterbalance valves.
Electro mechanical gives the operator an option to control a valve by an electrical signal. These control options – either being an on/off are commonly known as bang/bang valves. The other type is a proportional valve. Proportional valves control amperage to give a controllable range by either pressure or flow. Both types of valves can be poppet or spool type depending on manifold design criteria as well as the design of the specific valve.
Benefits of using integrated manifolds include:
Disadvantages of using integrated manifolds include:
Cost—In the case of a custom manifold that uses screw-in or slip-in cartridges, the volume must be high enough to offset developmental costs. Normally a prototype for an HIC (hydraulic integrated circuit) will be 2-3 times the price of production. Manifolds that use a subplate style mount are much simpler in design. The cost of the base manifold is low because it is an off the shelf item and offset by the slightly higher cost of the stackable modules.
Troubleshooting—Manifolds are sometimes viewed as a “black box” making troubleshooting a concern. However, if a system is properly designed and test points provided in key locations, finding the problem becomes much quicker and simpler. Its always a good idea to include test points on prototypes and remove later for production.
Non-repairable cartridges—Many cartridges are assembled in a way that makes them non-repairable and difficult to service. The only option available may be a new replacement cartridge. Keep in mind seal kits are available for all external sealing surfaces.
Non-standard cartridges—Valve cartridges are generally interchangeable, increasing availability. However, if a user selects a brand of cartridge that is not generally interchangeable with other models, then a cartridge failure can be a problem.
With the increasing need for smaller, more versatile units, a custom block may be just what you need for your application. You can save labor and material costs by integrating entire circuits into a custom block. However, this relies heavily on the circuit integrity, design expertise and manufacturing quality that has been built into each manifold. The quality and performance of any fluid power system is only as good as the level of expertise that has produced it.
For more information, contact your sales representative at IFP or set up a consultation with one of our engineers at EHA.