Compact flow prover

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. Means for returning the displacer from the downstream section to the inlet section following a proving cycle and means for detecting the longitudinal disposition of the displacer during a proving cycle are provided. The flow prover also includes an inlet conduit, an outlet conduit, and a valved bypass conduit fluidly connecting the inlet and outlet conduits. The displacer may be positioned within the cylinder by a member extending from the displacer into an external enclosure. The fluid pressure within the enclosure may be regulated to control the position of the displacer and to equalize unbalanced forces across the displacer.