| 摘要 |
EXHAUST VENT A novel ventilator having a one-piece plastic base with integral tubular member having a through passageway for flow of an exhaust gas stream. The tubular member is preferably molded simultaneously with the base, rather than glued, so that the base and tubular member assembly comprise not only a sealed tubular member, but provide a single, seamless part. Thus, moist air cannot leak out of the air flow path between the interior and exterior of a wall or roof. The ventilator is also provided with a screen and a flapper type lid for the tubular member. The flapper lid seals the outer end of the tubular member against inflow of outside air at those times when there is no exhaust gas stream impinging against the flapper 50 as to keep the flapper in the open position. The ventilator may be provided in a variety of colors by pigmentation of the plastic to be molded into the ventilator.
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