Compressor Efficiency - I just hurt my brain.

I used to work for a Natural Gas pipeline. The older compressors had cylinders large enough to climb into. New compressors were turbine types, so the math might be very different from anything we need for airguns. The compressors could either push or pull gas down the line. Since the line was bi-directional (don't ask me how it worked, I'm not an engineer), the compressors were large and if they got out of balance, you knew it in a hurry.

Best not worry too much about that article. Unless you want to push stuff down large pipelines, the article doesn't apply. Ours was a 42 inch pipe on the main line with smaller gathering systems at each gas field. The gas from the wellhead was gathered to the plant (Gas accounting is an interesting field where well owners are paid by volume and BTU content), processed at the plant then injected into the main line when demand needs the gas somewhere.

Anyway, keeping a 42 inch line at (I don't remember the pressure, but I think it was over 1800 PSI) over a 400 or 500 mile length was quite a feat. Worked great until some clown on a back hoe decided he didn't need the mandated pipeline inspector to oversee the dig. He died in a gas flame blowing right through the cab of the backhoe. That was back in the mid 1990's. Do be careful around the pipelines, treat them with respect.

Enough on Natural Gas, just ignore stuff like that because any compressors we use are what they are and whether they are 80% or 100% efficient, we really can't change it.