TRACERCO Diagnostics™ - Leak Study
A tank farm distribution manifold was used to route various materials from tanks to different columns in the refinery. A discrepancy was found between the measured flowrate to one of the columns, the rate indicated by tank level gauges and the flow to the tank. About 2% of the feed from the tank was not reaching the column. After recalibrating meters and confirming level gauge readings, the most likely cause appeared to be a leaking valve at the manifold allowing material to leak undetected into one of several other streams. Tracerco was called in to use their TRACERCO Diagnostics™ Leak Study technique to identify the leaking valve.
A soluble organic radioisotope was injected into the pump discharge line from the tank. Two of the streams (B&C) were sampled, because their flow rates were much greater than that from the tank. The other stream (A) was tested using an external detector, because its flowrate was comparable to the flow to the column. The same test was also used to measure the pump discharge flowrate using detectors 1 and 2. The presence of tracer in one of the sets of samples pinpointed the leaking valve. The leak size was calculated to be 2.2% of the flow from the tank. The measured pump discharge flowrate was within 1% of the expected value. At the next available opportunity, the leaking valve was replaced, eliminating the significant loss of product.