摘要 |
<p>There is provided a pilot valve ( 50 ), suitable for use in water and gas supply systems, the valve including biassing means ( 57 ), to control a gate ( 55 ), for controlling fluid flow through a control chamber ( 51 ), and a second chamber ( 52 ), which is sealed by a diaphragm ( 53 ), the second chamber ( 52 ), in use, receiving a control pressure for controlling the operation of the gate ( 55 ), such that an increase in control pressure acts to reduce fluid flow through the gate ( 55 ). The side of the diaphragm ( 53 ), against which the control pressure is not applied, is in fluid communication with the control chamber ( 51 ).</p> |