Espresso Machine (OPV) Over Pressure Valve is used to regulate the brewing pressure in an espresso machine and prevent overextraction of the coffee. OPV is an important component in the brewing system of an espresso machine and it needs to be set correctly to help you achieve the best quality espresso.

The Defender Series® Overfill Prevention Valve (OPV) prevents the overfill of an underground storage tank during a gravity-fed product delivery. It employs a revolutionary magnetically-coupled actuator system to provide positive shutoff. This unique method of shutoff eliminates any penetrations in the valve, making it both vapor and leak tight.

The Over pressure Valve (OPV) also known as an Expansion Valve, is an often neglected, but very important part of your machine. Vibration pumps produce around 15-18 bar unregulated, depending on type.

2024年4月25日 · opv其实就是over pressure valve 过压保护阀。 其作用就是在咖啡机器中，让咖啡酿造的压力不至于太高，一般设定在10bar以内，也就是说，单使用的咖啡粉过细的时候，这时候管路中的OPV就发挥作用，过压的水从OPV 支路上泄露出去。

2013年5月29日 · An OPV (Over Pressure Valve) allows the machine to reduce the pressure coming through the group head, typically by dumping excess water back into the water tank. It is partly a safety device to allow the release of excess pressure (say if the filter is blocked). Many OPV's are adjustable or moddable.

2023年10月31日 · You can reduce the pressure by adjusting the over-pressure valve (OPV) inside the machine. The OPV regulates the pressure, and by opening your Barista Express and unscrewing the OPV a little, you reduce the pressure for a smoother espresso.

2025年2月24日 · At its core, an Over Pressure Valve (OPV) is a pressure relief valve. In the context of an espresso machine, its primary function is to limit the maximum pressure exerted during the brewing process. Espresso machines typically aim for around 9 bars of pressure at the group head (where the espresso is extracted).

Complete new version Rancilio Silvia Expansion/OPV Valve, adjustable up to 10 Bar. Includes two copper gaskets, but does not include the 1/8" M compression fitting or nut. The new version (post 2008) Silvia's come with a flexible stainless steel hose that has a male thread on one end that threads directly into the valve.

Luckily there is a little device that is in some espresso machines called an Over Pressure Valve (OPV) this allows the excess pressure from the pump to be released. This allows for the coffee to be extracted at the right pressure. Unfortunately most machines if they even have an OPV have to adjusted when you first get them.

Here is the step-by-step process for adjusting the expansion valve/pump pressure on the Lelit Victoria espresso machine. (Difficulty ☕☕☕)