Pressure gauge siphons are used to protect the pressure gauge from the effect of hot pressure media such as steam and also to reduce the effect of rapid pressure surges. The pressure medium forms a condensate and is collected inside the coil or pigtail portion of the pressure gauge siphon. The condensate prevents the hot media from coming in direct contact with the pressure instrument. When the siphon is first installed, it should be filled with water or any other suitable separating liquid.