The Lee Company Electro-Fluidic Systems Division has been an industry leader in electromechanical valve and pump technology for over three decades. Manifolds offer several advantages compared to just tubing together discrete components, such as fewer leakage points, lower internal volumes, easier assembly into the instrument, and higher reliability. Our expertise in fluidics is drawn from a solid understanding of the application and the components involved. We can incorporate solenoid valves, pumps, passive components (i.e. restrictors) and active components (i.e. transducers) into a complete assembly that has been functionally tested per the application requirements. The different manufacturing techniques used to create such manifolds include conventional, multi-layered, and ant farm.
Conventional Manifold Technique
The conventional approach to machining a manifold is typically used when the valve count is minimal and the flow paths are straightforward. The design pattern of drilled passages enables you to locate valves as desired, with some limitations because the drilled passages must be straight and it requires the plugging of superfluous construction passageways. Integrating miniature valves into a common fluid manifold using conventional cross-drilled machining is a major step in the direction of simplifying otherwise complex valve and fluid passage configurations that once required numerous tubes from point to point.
Multi-Layered Manifold Technique
A multi-layered manifold is typically used when the functional requirements are more complex, which usually involves a higher valve count. This type of manifold design involves stacking together multiple layers of plates containing different machined or milled passages. The different plates are then bonded (epoxy, diffusion or solvent weld) together which allows the valves, pumps, and other fluidic sub-components to be located where appropriate for a specific application.
Ant Farm Manifold Technique
The Ant Farm Technique involves machining a series of intricate flow paths or channels into the face of the manifold. After the machining operation, a plate is bonded over the flow passages to complete the circuit. In complex applications, the channels can be milled into more than one face of the manifold block. This manifold machining technique further reduces the overall manifold size compared to the other technologies. This technology also lends itself towards building a modular design. The modular design includes provisions in the near fluid passage for O-rings to provide a seal between different sections of the manifold when mounted together. This erector set approach to manifold construction gives the designer more flexibility, especially if the application requires a distribution plate to redirect or prevent flow from one passage to another between sections. It also allows the designer to use a spacer plate to increase dimensions between sections when an oversized component or obstruction must be accommodated on the mounting surface.
Combination Manifold Technique
Combination manifolds are used to incorporate discrete components into a single unit. The Lee variable volume pumps have a port head that can be customized to incorporate solenoid valves, connections and sensors into a single package. This technique reduces the number of connections, the need for a second manifold and the overall package size. Combining several discrete components into a single one also reduces assembly time during instrument production.
Injection Manifold Technique
Lee injection valves minimize the fluid between the valve seat and the flow stream. This, in turn, minimizes carry over volumes. Staggering the valves on a multi-face manifold allows closer spacing and further reduces the length (thus volume) of the main flow passage.