2350 Industrial Road, Sapulpa, OK 74066 • Main: 918-445-1141 • sales@weamco.com Bulletin MPD-112 Toll Free: 800-331-3790 • Fax: 918-445-4617 • www.weamco.com 5-19 Page 4 of 8 Conventional Liquid Meter Provers Design and Construction V. Prover Construction and Components A. Pipe Elbows: Pipe elbows should be free of defects, dents, scratches or rust pits. They should be hand-picked for uniformity and roundness. B. Flange Seats: Flanges in the calibrated section are match-bored, machined with O-ring grooves for sealing, and dowel-pinned for alignment. C. Launch Chambers: The pipe section prior to the pre-run and calibrated section is used to launch and receive the sphere. Launch chambers should be two pipe sizes larger at minimum, to allow flow by-pass around the sphere which allows the sphere to decelerate. Also allowing easy sphere removal with the use of quick opening closures. Launch chambers can be horizontal, vertical, or inclined. Chambers should include Internal ramp and/ or stops depending on design configuration. D.  Sphere and Accessories: Inflatable sphere displacers are the most common used. The sphere is normally inflated from 2% to 4% larger than the prover pipe inside diameter. The sphere is filled with 50/50 mix of glycol and water. Proper inflation is vital for sealing and repeatability. Sphere materials available: Neoprene Nitrile Polyurethane (most commonly used and can be purchased in various durometers) Sphere accessories: Removal tools Pumps Inflation kits Sizing rings