Pressure gauge and instrument valves
Pressure gauge valves are installed in the piping to function as shut-off valves for a pressure gauge. It is very typical that a water syphon is also installed in the piping before the pressure gauge valve.
Different pressure gauge valves are available, but usually they are delivered either with or without an inspection flange. A model fitted with an inspection flange, a so-called engineer valve, is designed for applications where a third party inspector should be able to quickly check the line pressure with his/her own pressure gauge.