GB1363096A - Valve assembly controlling filling of a receptacle from a liquid feed line - Google Patents

Abstract

1363096 Valve assemblies J G THOMSON 28 March 1972 [6 April 1971] 10637/71 Heading G3P An apparatus for preventing the generation of static electricity, and therefore the risk of explosion, when filling a tanker with petroleum, comprises a valve assembly which provides an initial rate of flow which is less than that at which static electricity is generated but which increases to a maximum once the end of the apparatus has become submerged beneath the rising level of the petroleum. In one embodiment. Fig. 2, the valve assembly is mounted in a filling line 11 and comprises a spoked main ring valve 25, a pilot valve 40 for controlling the flow of liquid to the underside of a piston 26 forming part of the main valve, a shut-off valve 80, and a liquid level sensor 15. The pilot valve member 48 is attached to a diaphragm 45 and normally closes a passage 111. The cut-off valve comprises a spool 101 attached to a diaphragm 90. In use, liquid entering at A trickles through restricted passage 21 and passes through line 11 to the tanker. As the liquid level rises in the conical portion 63 of the sensor 15, the pressure on the underside of the diaphragm 45 is increased thereby causing the valve member 48 to move to an open position. Liquid also entering at B can now flow through passages 56, 110, groove 103, and passage 111 to the underside of piston 26. As the piston is lifted the main valve 25 is moved to its fully open position. Once the liquid level in the tanker closes a port 98 in the line 11, the pressure on the right-hand side of diaphragm 90 increases, thereby causing the spool 101 to move to the left. In this position, the spool diverts liquid from passage 110 through groove 104, into passages 107 and 108, and thence to the topside of the piston, whilst simultaneously venting the underside of the piston through passage 111, groove 103 and passage 105. The main valve 25 moves to a shut-off position in consequence. In another embodiment, Fig. 3, each side of the diaphragm carrying the pilot valve member 123 is vented to atmosphere. However, as one of the vents 139 is closed by the rising level of liquid, a vacuum is generated in the chamber 126 by virtue of liquid flowing past a U-tube 135. This causes the pilot valve to actuate the main valve. A flexible diaphragm 155 serves to reduce flow turbulence.