ASME-Landmark:Southern Gas Association-PCRC Analog Facility

The Southern Gas Association (SGA) analog was commissioned by the Pipeline and Compressor Research Council (PCRC) to help design safe compressor systems, free from damaging pulsations. Built in 1955, the analog computer is the first device of its kind applied to natural gas pipeline systems and has been used to create or modify more than 10,000 installations worldwide in natural gas, petroleum, chemical, and nuclear industries. Analog computers predict physical behavior by simulating it in analogous processes instead of solving equations.

This analog uses electricity flowing through coils, capacitors, and resistors to model the fluctuating flow of compressed fluids. It is remarkable for being used long after other analogs were replaced by digital computers. Notable projects using the analog include the Alyeska Pipeline that brings North Slope oil down through Alaska, the first carbon-dioxide (CO 2) pipeline built for Canyon Reef, and the first reciprocating compressor high-pressure gas reinjection system on the Statfjord production platform in the North Sea.

When the American natural gas industry began to flourish after World War II, pipeline companies anticipated adding hundreds of thousands of horsepower to compressor stations. The resulting high pulses caused severe vibrations that literally rumbled through pipes, causing potential damage. In the early 1950s, the Pulsation Research Council (which later became the PCRC) formed a team of developers with technical advisors from oil and gas-transmission companies. Development work began in 1955 and an analog simulator was demonstrated that same year. A gas pumping system analog patent (No. 2,951,638) was filed on May 31, 1955. See ASME website for more information