This paper describes the design, construction and capabilities of a high ve
locity air-sand erosion rig. It has been designed with the aid of computati
onal fluid dynamics to approximately simulate the erosion conditions often
experienced by subsea choke valves used in the offshore oil industry. It ha
s also been designed to evaluate the erosion performance of CVD diamond coa
tings at sonic velocity. The rig is of the gas-blast design in which solid
particles, typically sand 60-660 mu m in size, are injected into a high vel
ocity air stream and accelerated down a 16-mm-diameter tube, 1 m in length,
before striking the sample under test. Tests can be carried out with parti
cle velocities of up to 340 m/s under a wide range of sand fluxes, impact a
ngles and standoff distances. The results of pressure, velocity and sand fl
ux calibration work are described. In addition, preliminary experimental da
ta on tests carried out on mild steel, bulk and sprayed tungsten carbide ar
e also presented. The flexibility of the air-sand rig allows the erosion be
haviour of materials to be studied under a wide range of conditions. (C) 19
98 Elsevier Science S.A. All rights reserved.