With all the as-built documentation in-hand, we were able to perform a desktop review of the design and installation. Performing this desktop review, prior to an on-site analysis, allowed the design team to generate preliminary feasibility planning and increase the efficiency and effectiveness during the on-site field review.

Utilizing the Method 1 – Environmental Protection Agency’s (EPA) Average Emission Factor Method, outlined in API-Pub-4638, we quantified the potential methane emissions within the facility. In addition to this analysis, an electrical hazard classification study, per API RP-500 identified the electrical installation requirements within the enclosed compressor building.

Considering these two pieces of information, and the utilization of natural ventilation during a worst case (wintertime) scenario, we calculated ventilation requirements and provided associated recommendations. Those recommendations included modifying building openings and louvers to achieve the required level of natural ventilation, to meet electrical hazard Class I Division 2 classification (1/4 LEL based on API 500 methodology).

After reviewing the results of the EPA Average Emissions analysis within the compressor building, the results were discussed with the client and a permanent gas monitoring system with proper Emergency Shutdown (ESD) provisions was recommended. The client agreed that was the best option and we provided the design for the gas monitoring system. The system provides real-time, continuous validity of the calculated classification, capable of initiating ESD protocol, in the event of emissions exceeding the calculated rate due to a failure.

The client now has the information and necessary systems to operate its newly acquired natural gas infrastructure, with the utmost confidence in its safety.