Weights and Measures Regulations (C.R.C., c. 1605)

297. A tank and its piping system and any equipment or accessories that can affect its accuracy of measurement shall be of such design, composition and construction that when a delivery is made from any capacity indication, the quantity of liquid delivered through any discharge valve rigidly connected to the tank is within the prescribed limits of error for the tank.

298. The shells or bulkheads of a tank shall consist of such material and be so constructed that they will not become distorted under any condition of loading under normal conditions of use.

299. A tank shall have an effective means of automatic venting to permit the free passage of air into and out of the tank when it is emptied and filled.

300. Subject to section 320, there shall be no pipe or other flow connection between two or more tanks that are separately calibrated, but a battery of calibrated tanks may be connected to a common discharge manifold that prevents flow from one tank to another.

301. The capacity indicators on a tank shall consist of

• (a) graduations on or adjacent to a gauge glass or tube; or

• (b) appropriate internal capacity indicators.

302. A capacity indicator shall only be installed in a tank at any level where a quantity of liquid equal to the limit of error referred to in section 325 for the indicated quantity causes the liquid at that level to rise by at least 2.5 mm or 3/32 of an inch.

303. A maximum capacity indicator shall be positioned to allow a volume equal to at least one per cent of the capacity of the tank for the thermal expansion of the liquid.

304. When an internal capacity indicator is installed in a tank,

• (a) the indicator shall be attached to a permanent section of the tank; and

• (b) a means shall be provided to attach a seal on the indicator.

305. A tank equipped with an internal capacity indicator shall have a suitable opening for the convenient installation, adjustment and sealing of the indicator assembly and the capacity indicator shall be located so that it can be seen under normal conditions of use.

306. Gauge glass fittings shall not, except on tanks for liquefied gases, be of the ball check type or be of any type designed to prevent loss of liquid in case of glass breakage, but a bottom gauge glass fitting may include an emergency valve if means are provided thereon to allow an inspector to seal the valve in the open position.

307. The discharge hose on a tank that discharges by gravity shall normally be of the dry hose type, without a shut-off valve at its discharge end, shall be of such length, size and stiffness as will ensure its complete drainage and shall be provided with a means to indicate when all of the measured liquid has been delivered thereby.