With pig signallers, the real-world application is far more important than the often-inflexible specification and the need to standardise. To truly get the optimal solution and therefore the biggest return on your pig signallers, an understanding of the job at hand, the types of pigs utilized and why are paramount.
Datasheets clearly outline the capabilities of various pig signaller models: magnetic pig signallers highlight the need for magnets, ultrasonic units claim to detect all types of pigs in liquid systems and acoustic pig signallers go one step further by detecting any pig in any system. While these statements are true, they only paint part of the picture when it comes to the “best solution” perspective.
In this industry which typically operates on an EPC model for CAPEX developments and where standardization is often a requirement, the acoustic option appears to be the obvious choice. The benefit of the acoustic signaller certainly applies when dealing with pipelines that are well distanced from background or intermittent noise. However, in relatively “noisy” environments, challenges arise. Background or foreground noise can potentially mask the passage of the pig or generate noise falsely identified as a passing pig.
Consider scenarios like a helicopter causing background noise or noise related to the pig receiver’s operation and instrument proximity to the kicker line. The pig receiver process, valve alignment and changing acoustic profile during pig receipt contribute to the complexity. Therefore, a prudent approach involves tailoring the best solution to the specific application, considering multiple factors and opportunities.
For metal bodied pigs, fitting them with magnets and using a magnetic signaller provides a more direct response, minimizing false positives and missed pigs
In liquid systems, an ultrasonic sensor proves effective for all pig types, again offering a more direct response.
If using an ultrasonic signaller, strategic sensor placement at challenging locations such as pig launch and receipt points, allows for detection of stalled pigs.
In cases involving foam pigs in wet gas systems for liquid management, the acoustic pig signaller stands out as the most suitable choice.
If the acoustic is the chosen technology, false positives can be screened out by communicating with the signaller.
In conclusion, the key lies in aligning the pig signaller technology with the unique demands of the application, considering factors like pig type, system characteristics, and environmental conditions to ensure optimal performance and reliability.
Get in touch to find out which pig signaller is right for you.
