| 摘要 |
<p>A valve 10 for use in a fire extinguisher includes isolation valve 12 comprising a ball-valve in which a valve 14 provides three channels 20, 22, 24 extending from an outer surface of the valve to a central void 26, effectively forming a T-shaped conduit within the valve 14. The first channel 20 and the second channel 22 provide a linear passageway through the valve member 12. The third channel 24, arranged perpendicularly to both the first channel 20 and the second channel 22, is of a smaller cross-section and provides a bypass vent. The valve 14 is arranged to either open a passageway between a pressurised extinguishant provided in a cylinder and outlet 32 or the valve 14 closes this passageway to prevent extinguishant being released from the cylinder. In both open and closed positions, a channel in the drive stem leads to a pressure gauge such that the pressure within the system can be monitored. The drive stem is concealed when the system is live preventing unauthorised movement of the isolation valve.</p> |
