Pressure Gauges Glycerine Filled

State the range, the dial size, the connection position and mounting (bottom direct, rear direct, rear with front flange, rear with U-clamp) and the thread. A rear-connected panel gauge cannot replace a bottom-connected line gauge, and a G1/2" gauge will not screw into a G1/4" port.

Pick the range so the working pressure stays well inside it. A typical EN 837-1 liquid-filled gauge is rated for steady pressure up to 3/4 of full scale, fluctuating pressure up to 2/3 of full scale and full scale only for a short time; a pulsating pump discharge therefore needs a higher range than its normal reading suggests.^[2]

Ask for the accuracy class and the standard to be stated (class 1.6 to EN 837-1 is common for 63 mm gauges), the wetted materials (the typical gauge has a copper-alloy element and movement) and whether a restrictor is fitted — some high-range liquid-filled gauges come with a brass restrictor in the connection to damp pulsation.^[2]

Liquid-filled Bourdon gauges are built to EN 837-1. A representative maker’s data sheet for a glycerine-filled 63 mm gauge gives accuracy class 1.6, IP 65, a permissible ambient temperature of –20 to +60 °C and a medium temperature of +60 °C maximum — so check the medium temperature before fitting one directly on a hot line.^[2]