Valve Leak Detection using Acoustic Emission

 

Site experience has shown that 5-10% of valves leak, and 1-2% of valves cause 70% of total loss. Savings in excess of $100,000 per site are easily achieved. Where gas recovery systems are in use, monitoring product valve leakage helps to identify and estimate the extent of the downgrading of valuable products to fuel gas due to valve leakage. This is something previously identified by the flare, but goes unseen with gas recovery in use. Cost savings are achieved in maintenance planning, troubleshooting plant operations and monitoring of losses for environmental purposes.

 

มล procedures for the detection of leaks through valves have been developed for use in refineries, chemical plants and offshore platforms. It enables estimation of through-valve gas losses and leak rate. Tests are carried out using the PAC's 5131 portable leak detector and D9203IS sensors. A more than 10-year database built up in cooperation with BP (British Petroleum) relates acoustic signal level to gas losses for various valve types (ball, relief, plug, gate, globe, butterfly), of different valve sizes (1" - 18") and working within 0.5 to 140 bar pressure range.

 

Losses Calculation

Using their database, BP developed a calculation that estimates losses from the input data. This is provided as part of the package in a spreadsheet form, which makes use very easy on a PC. It is particularly useful on large sites that have many hundreds of valves. It is also provided in a graphical form for quick use out in the plant.

 

Advantages

• Totally non-invasive.

• Simple & Intrinsically safe operation.

• Portable instrumentation.

• On-line measurement, valve tested within seconds.

• Savings up to $100.000 per site from loss control.

• Cost reduction of maintenance and plant operations.

• Monitoring losses for environmental purposes.