ShurFlo Pressure Regulator none adjustable 30 PSI #183-130-NF

Most espresso machines that can be plumbed in come with a stainless steel braided water line to connect them to your water source. If you read the user manual you'll notice the maximum allowed water pressure should not exceed 2-3 bars.

This industrial pressure Regulator keeps the water pressure at 2 bar (30 PSI)

Shurflo Water Pressure Reducer Valves (WPRV) are fixed pressure water-reducing devices (non-adjustable)
• Minimizes incoming water pressure fluctuations while guarding against pressure spikes
• Actual pressure reduction is dependent upon input pressure and outlet flow rate

Comes with 2 John Guest Push-In style fittings for 3/8" OD Tube.