Abstract: A filter device wherein inlet and outlet chambers are spaced from each other by a segment of filter media is positively locked in a condition whereat the chambers are sealed with respect to each other and the atmosphere by a hydraulic power device to which hydraulic pressure fluid is delivered at a predetermined pressure value. Filtrate is then delivered to the inlet chamber at a pressure which increases in value as the filter media becomes fouled with particulate.

Abstract: Filter apparatus and method comprising a pair of filter shells having communicating flow passages and a filter media between the shells. Upon the clogging of the filter media, the inflow of liquid is stopped, the shells drained of remaining liquid and separated to allow the filter media to be removed and replaced. The shells can be interlocked when closed, and a mechanism is provided to hold one shell in locked engagement against the other when filtering. The one shell can then be released to allow the shells to separate when the filter media is to be replaced.

Abstract: A filter device wherein inlet and outlet chambers are spaced from each other by a segment of filter media is positively locked in a condition whereat the chambers are sealed with respect to each other and the atmosphere by a hydraulic power device to which hydraulic pressure fluid is delivered at a predetermined pressure value. Filtrate is then delivered to the inlet chamber at a pressure which increases in value as the filter media becomes fouled with particulate.