What is inside a retail gas station "above the ground" part

Probably a small computer. Notta whole lotta.

Apparently these contain very large vacuum pumps. Every time I leave one I find that my wallet has been sucked clean.

Usually a pump with dual heads (2 pumps if it also has a diesel nozzle) Metering unit which controls how much low grade to mix with the high grade for the blends. Set of flow meters Display, selection, control boards, receipt printer and the credit card reader head.

printer and

That's great to know! Thanks! Those pumps, are they diaphragm pumps or something else?

I was kind of hoping that there is some kind of a pump in there.

printer and

There are no pumps in those units, modern gas stations use submersible turbine pumps similar to well pumps. All that is in those dispenser units is a set of metering units, possibly some filters and a PC with card and prox readers. I'm afraid scrap wise the stainless steel cabinet it's all in is probably the most valuable part.

Take a look at this thread for more info than you ever wanted on fuel stations:

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Yes, there is not much, indeed.

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Not to sure about that, around here you can hear the pumps pumping. But even if modern pumps use STP's, if those are older pumps they will have the pump inside them.

Remove 333 to reply. Randy

receipt printer and

You may be hearing the flowmeter turning. On the older gas pumps I'm familiar with the flowmeter was essentially a positive displacement motor driving the tabulating mechanism. It appears that the pump on the page cited has a similar arrangement except the "motor" (the silver device in the second pic) drives an encoder instead of a mechanical display as in an old pump.

receipt printer and

I think they would have to be quite old to actually have pumps in them. What you hear is more likely to be either the noises from the metering units, or in some cases if the area is quiet you may hear the in-tank pumps whirr transmitted through the fuel lines much the same way as you can hear your well pump 200' down the well if you listen at the plumbing in the house.

If you do wind up getting them, I would be interested in a few of the displays, if they are color.

I was replying to the last question and implying that your first two were correct.

But, Iggy Poo, if you must ask, there are certainly light bulbs, screws, and sheetmetal panels and framework inside, too. Last, but not least, several stickers for inspectors and/or calibration will be hidden inside. Perhaps a plastic window or two hide there, too.

a pretty good high volume pump, computer controls and an RS-485 gizmo and at least 1, if not two motors

Gunner