Abstract
A FAC (flow accelerated corrosion) test was performed for straight pipe composed of SA335 Gr P22 and SA106 Gr B (SA106-SA335-SA106) including a weld, as a function of the flow rate in the range of 7 to 12 m/s using the FAC demonstration test facility. Afterward, the experimental pipe was examined destructively to investigate any entrance and galvanic effects. In addition, the FAC rate obtained using a 50mm inner diameter (2 inch) pipe specimen was compared with the rate obtained from a rotating cylindrical electrode. The effect of the complicated fluid formed on the elbow and orifice of the pipeline was also evaluated using another test section designed to examine the independent effect of orifice (orifice 1) and elbow (elbow 1) with distance, and the combined effect on orifice (orifice 2) and elbow (elbow 2). The test was performed under the following conditions: 90-150 °C, DO <5 ppb, pH 7 and flow rate of 3-5 m/s. The FAC rate was obtained using commercial room temperature ultrasonic testing (UT) after each test and high temperature UT developed at KAERI during the test, as well as commercial high temperature UT (Rightrax). This FAC rate was compared with the rate from a FAC prediction program. Surface morphology and FAC behaviour with the flow direction (low Cr to high Cr or high Cr to low Cr) and the distance following single orifice, single elbow and combination of orifice and elbow in the radial direction were investigated.
