Manifolds are piping systems used to mount multiple filters in parallel or to provide a manual or automatic by-pass to a filter installation. Filters, piping, valves, controls, wiring and hardware are all included. Installation costs are minimized with manifold systems. When existing piping has a given flange spacing into which the filter must fit, the manifold can be fabricated by Orival, Inc. to fit the desired spacing in order to allow for quick installations.