The transportation of refined hydrocarbons such as motor spirit, kerosene and gas oil from refinery to major customers is typically through a pipe line. However, it is often not economically viable to have dedicated pipe lines for each product. Therefore, batches of different products are sent using the same pipe line.

When the oil is received it needs to be directed to the appropriate storage tank, whilst minimising cross contamination with the preceding and following products in the pipe line. Traditionally, in-line density instrumentation has been used to detect the passage of the interface between the two products. This then triggers the actuation of valves to ensure that the flow of product is diverted from one tank to another at the correct time, minimising cross contamination.

Effective operation relies on the accurate sensing of density by the sensor. Because the sensor is in direct contact with the flowing liquid, there is the potential for fouling to occur resulting in a failure to detect the presence of the interface.

SAFIA analysed this issue and proposed the use of ultrasonics to detect the interface based on differences in the speed of sound associated with the different hydrocarbon products. By employing the clamp-on ultrasonic sensors utilised by SAFIA, the issue of fouling was eliminated ensuring correct operation at all times

Working with Saudi Aramco, SAFIA undertook numerous evaluation studies to demonstrate the effectiveness and reliability of this technique.
SAFIA are pleased to offer clamp-on ultrasonic interface detection systems for use on new or existing hydrocarbon transfer systems.