Abstract: A flow prover with seal monitor includes a housing with a cylinder and a piston-like displacer sealingly conveyed along the cylinder by the fluid flow to be measured. The displacer includes at least one rod that extends telescopically through the housing. A pair of conduits may be arranged concentrically within the rod, one in communication with a volume between a pair of seals whose integrity is to be monitored and the other in communication with the fluid in the housing. The conduits each communicate as well with a pressure sensor located outside of the housing. The sensor may be mounted on the rod to sense the absence of a pressure differential between the conduits, which indicates a seal failure. The sensor may provide an indication, which may be detected at the end of a proving cycle, that the seal integrity was maintained throughout the proving cycle.

Abstract: A compact flow prover for calibrating continuous flowmeters includes a measuring housing comprising a main cylinder having a substantially uniform inside diameter and inlet and downstream sections having inside diameters greater than the main cylinder. The compact flow prover is provided with a displacer movably disposed within the housing having seals which form a fluid barrier while the displacer is disposed within the main cylinder. Inlet and downstream section guide means are provided to maintain the displacer in axial alignment with the main cylinder while the displacer is disposed within either of these sections, assuring smooth exit and entry. The displacer is provided with seals which are circumferentially compressed when the displacer enters the main cylinder and may be statically or dynamically monitored for integrity without an external pressure source.