| 摘要 |
Plants with a number of tanks producing adhesives and with their gases continuously purged with inert gas have a gas disposal equipment. The mixed inert gas-evolved gas is passed from all the tanks through a common pipeline with pressure control valve into a processing plant; the valve is regulated to maintain a constant gas pressure of 0.1-0.2 mbar. A feed pipe beyond the valve supplies a larger volume of air than that of the inert/evolved gas mixture, and a fan maintains a constant under-pressure of 3-4 mbar in the common pipeline beyond the valve. The valve is a pendulum non-return type. An annular housing contains a flap which revolves eccentrically above the centre line on needle bearings, these bearings engage correspondingly tapered holes in the rim of the flap, and they have segmental stops matching the eccentricity of the axis of the flap; the housing has a groove one each side to open the flap in one direction only, and an adjustable counter-weight is provided on the flap underneath the axis of rotation.
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