Liquefied Petroleum Gases Bulk Storage Regulations (C.R.C., c. 1152)

30 (1) Unless filing is controlled by weighing, tanks shall be equipped with a fixed tube liquid level, a rotary tube, or an adjustable slip tube gauge, or other gauging device that will ensure that the maximum permitted filing density is not exceeded.  If the gauging device is a float type or a pressure differential type, the container shall also be provided with a fixed dip tube, rotary tube or adjustable slip tube gauge.

(2) Gauge glasses of the columnar type shall be restricted to charging plants where the fuel is withdrawn in the liquid phase only.  They shall be equipped with valves having metallic hand wheels; with excess flow valves and with extra heavy glass protected with a metal housing applied by the manufacturer.  These gauges shall be shielded against the direct rays of the sun.