In addition to providing a neat and logical layout, consolidating components into a manifold reduces space and pressure drop. This results in fewer fittings, more efficient assembly times and reduced leak points. Manifolds are sometimes viewed as black boxes, as they can be highly complex with upward of 500 holes communicating with each other and many valves on a single block. The alternative to manifolding a system is to mount all valving in individual blocks and plumb hoses in a manner consistent with the circuit. This dramatically increases the visual nature of the system, introduces infinitely more leak points and is generally an unacceptable alternative to manifolds. If a system is properly designed and test points provided in key locations, finding a problem becomes much quicker and simpler with a manifolded system. If transducers and other data collection devices are connected to these test points, the data may be linked into the machine controller and operationâ€™s terminal displays. Manifolds generally operate within 500 to 6,000 psi operating pressures. With additional design considerations, 10,000 psi can be achieved within the scope of steel and stainless-steel manifold designs. Although not typical in hydraulic application, 50,000 psi can be achieved with special materials and design nuances. Manifolds come in three basic types. Most common is a solid-block design that contains all drilled passages and valves for an entire system. Typical materials for solid-block manifolds are aluminum, steel and ductile iron. Block weight can reach 100,000 lb. Modular-block, or stackable design, is a subset of the drilled block. Each modular block usually supports only one or two valves and contains interconnecting passages for these valves as well as flow-through provisions. It normally is connected to a series of similar modular blocks to make up a system. This system is known for its flexibility within a limited range of circuit complexity. Modular block designs are generally held together with tie rods or a system of tapped holes that allows for machine screw connections. Lastly, laminar manifolds complete the manifold category. Laminar manifolds are usually made of steel, with passages milled or machined through several plates of metal. These plates are stacked or sandwiched with the various fluid paths determined by the shape of the machined passages. Solidmetal end pieces are added, and the whole stack is brazed together. Internal passages can be cut to any shape needed, so nearly any flow rate can be accommodated with minimal pressure drop. Laminar manifolds are always custom-designed. Valves and other connections can be located where appropriate for
FLUID POWER WORLD
6 â€˘ 2016
HYDRAULIC MANIFOLDS offer a variety of paths for fluid to flow through a hydraulic system. These acrylic models demonstrate complexities in their design.
6/17/16 9:22 AM
Fluid Power World Handbook 2016