Principles of sanitation applicable to the construction of new vessels.

Date:
[1949]
Catalogue details

Licence: Public Domain Mark

Credit: Principles of sanitation applicable to the construction of new vessels. Source: Wellcome Collection.

    20/122 (page 6)
    (4) Water-level indicators actuated by air pressure. The air may be supplied by a hand pump, an independent compressor, or through a ‘press-on’’ valve with a filter or liquid trap in- stalled in the supply line from the main compressed-air system. (5) An enclosed float gauge. (6) A water-operated pressure gauge. 1.45 Drains. The potable water tank should be provided with a means whereby the tank can be completely drained. The drain opening should be large enough to facilitate flushing the tank and at least 14 in diameter. If drainage is by gravity flow, the opening should be in the bottom of the tank and should terminate flush with or below the inner surface of the tank bottom. The installation should be such as’ to avoid a rein- forcing plate, a raised welding bead, or a protruding pipe in way of the hole which would prevent complete drainage. This can be accomplished as shown in Fig. 2,A and B. If a potable water pump suction line is used as a drain line andcannot be installed the same as a gravity drain, then it should draw from a sump as shown in Fig. 2,C. TANK SIPE COUNTER-BORE AND FILLET WELD BOTTOM oF TANK WELD BOTTOM OF TANK) TT Cie SET ERNMIE = A screw plug or capped nipple should be installed as a drain only when it 1s easily accessible and the water can be wasted directly therefrom. A pipe drainage system should be independent of all other water systems and should be protected as specified inSec. 6.22, p. 26. Ifa locking-type valve is not provided, the end of the drain line should be plugged or capped to prevent the loss of water in case the drain valve is loosened by vibration. The screw plug or the drain cap should be secured to the pipe or bulkhead by means of a keeper chain to prevent it from dropping to the deck. | The discharge to waste should be from the discharge main at a point before any branches take off to the distribution system. A valve should be installed on the main immediately beyond the drain line take-off. 1.5 DISTRIBUTION 1.51 Pump Suctionor Feed Line. The suction line of the potable water pump should not be cross connected with the piping or storage tank of any non-potable water system either directly or through a manifold. There