| 摘要 |
<p>The floating-roof tank is constructed by the erection of a number of short steel angle supports (4) on a baseplate (3) after the sidewall (2) has been erected to a given height. The floating roof is formed on the supports by mounting pontoons (5) round a cover plate (6), and inflatable seals (8) are then fixed in position round the outside of the pontoons, compressed air being delivered to them to seal off the gap between the pontoons and sidewall. Air is blown into the chamber formed under the floating roof, so that this rises in a horizontal position to a predetermined level with the aid of a winch rope (14), forming a sufficient working area underneath. The roof is then secured at the higher level by means of a number of supporting columns (18).</p> |
