Hi all,
Wrapping up the build thread for the Worthington Brewery Pump model. These brewery pumps were intended for use pumping beer between brew tanks during manufacturing. They made different size versions, from 4" to 10" diameter pistons. Here is a picture of it all complete:
And a video of it pumping water - it measures out to pumping 3 liters per minute at 60 psi of compressed air inlet.
It has two 1.25" diameter steam pistons, with 3/4" pump plunger pistons. There are 4 inlet and 4 outlet valves per cylinder. Here is a cross section diagram of it from one of the old Worthington catalogs:
Note the extra pair of passages in the steam cylinder and the longer than normal D valve. Sicne there is no crankshaft to control travel, and each piston is linked to the other cylinders valve, these passages stop the piston movement near the end of travel without hitting the cylinder cap. As the piston gets near the end, it covers the inner passage, which is the exhaust passage, trapping the remaining steam at the end of the cylinder and bringing the piston to a soft stop. The outer passage is still clear, and can bring in new steam when the other piston gets to the end of its travel and opens this pistons valve. This diagram highlights what each passage does:
