LYCOS RETRIEVER 
Espresso Machine: Pressure
built 176 days ago
Just like the commercial machines, the Rancilio Silvia features a three-way solenoid valve that instantly releases any built up pressure in the portafilter once you complete an espresso shot. This allows for instant reloading of the machine for another shot, and no mess or fuss when removing the portafilter.
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Many high-end home and all commercial espresso machines feature a pressure relief system that helps reduce splatter if you should inadvertently remove the portafilter too quickly. The pressure relief system ... greatly reduces dripping after the brew switch has been turned off resulting is a “dry puck” of coffee grounds for easier cleanup. This is done thanks to the three-way solenoid valve.
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These Italian espresso machines offer old world style and craftsmanship with the ability to brew exquisite espresso; ... they do require the most skill to operate and are only recommended for the hands-on espresso purist who is willing to experiment. Pump pressure is developed by manually pulling the lever.
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