| 摘要 |
<p>A tempering valve for use in hot water supply systems, having a mixing chamber (5) arranged to mix water received from a cold water supply (2) and a hot water supply (3), and an outlet (4) through which the mixed water is discharged. The valve has a thermostatically controlled closure member (7) which is movable between two valve seats (19 and 20). Passage of cold water to the mixing chamber (5) is at least inhibited when the closure member (7) engages one seat (19), and passage of hot water to the mixing chamber (5) is prevented when the closure member (7) engages the other seat (20). Between those two positions, the closure member (7) proportionally controls flow to the mixing chamber (5). Fail safe means becomes operational in the event of failure of the thermostat (8), and that means may open a secondary flow passage (30) for cold water, or it may include a device, such as a coil operated disc valve (149) (Figures 7-9) which functions to shut-off escape of water through the valve outlet (104). Flow inducing means, such as a venturi (140, 142) (Fig. 6) may be incorporated to induce flow from the hot water supply (103) if that supply is at a pressure below the cold water supply (102).</p> |
