STS Case Studies

Centrica plc is a major UK energy

company operating predominantly in the UK and North America.

STS was commissioned to carry out leak testing and evaluation surveys on Centrica’s Hydrocarbon Dew Point Chillers at their South Morecambe Gas Terminal in Barrow in Furness, UK.

The chillers use refrigerant R22, which is an HCFC substance listed in the Environmental Protection (Controls on Ozone Depleting Substances) Regulations 2011 (1005/2009). This regulation prohibits and controls the production and use of ozone-depleting substances and Centrica is obliged to regularly leak test, repair leaks and record refrigerant loss from, and additions to their plants.

The plants were designed and constructed to typical petrochemical standards of their day and consisted of many threaded and flanged connections and fittings. Two 1MW plants were surveyed and had an assessed total of 1,600 potential leak paths. The overall aims of the exercises were to:

1. Identify leak paths
2. Estimate the annual quantity of R22 leaking from

individual leak paths

1. Physically tag and photograph leaks
2. Mark leaks on the P&ID’s
3. Report and make recommendations to eliminate

or reduce and manage R22 leakage

The evaluation and analysis of the measured and collected data provided Centrica with a representation of leak paths on their systems which allowed them to plan a leak repair programme to eliminate or reduce and manage R22 atmospheric leakage and thus reduce the plants harmful environmental effect.