| 摘要 |
<p>The push button tap head is screwed into a tap, in place of the conventional head. The existing valve seat is permanently closed by a seal. When the valve is open, water flows through the central orifice into the tap outlet. The tap is opened by pressing the head to force the valve off the seat. When the valve is depressed, the piston in the cylinder moves down and water is forced past the flexible seal to fill the chamber. When the button is released the water can only pass slowly through the calibrated hole and the valve closes slowly.</p> |
