Determination of installation effects for a 100 mm orifice meter using a sliding vane technique

Abstract As part of the Gas Research Institute Metering Research Facility Upstream Effects programme, a sliding vane technique is used to investigate the effects of straightening vane location on orifice discharge coefficient and velocity profile in a D = 102 mm orifice meter installation. A standard ‘concentric pattern‘ 19 tube bundle straightening vane with a length to meter tube diameter ratio of 2.5 was modified so that the distance, x, from straightening vane to orifice plate could be changed rapidly without reassembling the meter tube. This paper describes sliding vane experiments made with nitrogen gas at a pressure of 724 kPa (105 psi) in 45D and 19.5D long meter tubes downstream of a single 90° elbow at a Reynolds number of 8.8 × 10 5 . Results are presented for the variation of orifice discharge coefficient for β = 0.75 as a function of sliding vane location from x/D = 5 to 42.5. Complementary results are presented for the axial velocity profile distribution measured at the orifice location in vertical and horizontal planes of the 45D meter tube by hot-film anemometer at x/D values of 5, 11, 21, 39 and 42.5.