Manifolds

Manifolds are primarily used in hydraulic and pneumatic fluid power systems to control the flow of pressurized oil or air through circuits that power machinery. 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. Integration and control are two reasons manifolds are often used in fluid power systems.

Three styles of functional components available for integrated manifolds are:

  • Cartridges that thread into the manifold
  • Cartridges that slip into the steel or aluminum manifold
  • Functional modules that stack on top of the manifold under the directional control valves

There are many different types of mechanical and electro-mechanical valve cartridges available including:

Proportional

  • Flow
  • Pressure
  • Directional

Solenoid

  • Directional (2W/2P, 3W/2P,3W/3P, 4W/3P,4W/4P, 6W/2P)
  • Pressure - 2 Point (used in conjuction with mechanical pressure or compensator)

Pressure

  • Relief
  • Reducing (or combination reducing/relieving)
  • Compensation
  • Sequence
  • Logic

Flow

  • Check
  • Throttle
  • Flow Control
  • Flow divider (or divider/combiner)
  • Flow fuse
  • Air bleed
  • Pilot to close

Load Control

  • Pilot-operated check
  • Counterbalance
  • Load adaptive

Logic

  • Switching
  • Modulating (unloadi ng)
  • Compensation

Multifunction

  • Relief with check
  • Directional with Load sense

Accessories

  • Cavity plugs
  • Gauge snubbers
  • Filters

There are both advantages and disadvantages of using manifolds for hydraulic systems, for example:

Disadvantages

  • Cost- In the case of a custom manifold that uses threaded or insert cartridges, the volume must be high enough to offset developmental costs. Manifolds that use stacking modules are much simpler in design. The cost of the base manifold is low and offset by the slightly higher cost of the stackable modules. 
  • Non repairable cartridge - Many cartridges are assembled in a way that makes them nonrepairable and difficult to service. The only available option may be a new replacement cartridge.
  • 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.

Advantages

  • Cost - Cartridge valves are relatively inexpensive
  • Labor - Cartridges &surface mount valves require fractional time toreplace as opposed to in line valves
  • Valves - No disruption of plumbling - Replacement/servicing of cartridge or surface mount valves rarely require disassembly of fluid conductors (hose/pipe/tube)

With the increasing need for smaller and 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.