GB1211199A - Improved method of testing for closure of series connected fuel valves - Google Patents

Abstract

1,211,199. Valves and valve testing. GAS COUNCIL. 7 Feb., 1968 [14 Nov., 1966], No. 50860/66. Heading F2V. [Also in Division F4] A method of testing whether two fuel valves 12 and 13 series connected in a fuel line 10 to a burner are effectively closed comprises subjecting the enclosure 15 between the valves to suction and confirming that the resulting pressure in the enclosure 15 is consistent with the values being closed. The method may be applied in three ways: firstly, the enclosure 15 is evacuated and a check made (by means of a pressure switch P) that a predetermined pressure is reached in a predetermined time; secondly, the pressure in enclosure 15 is reduced to a predetermined value and the enclosure 15 shut off from the suction source and the pressure checked that it does not rise above the value in a predetermined time; thirdly, the first and second ways are combined sequentially. The two valves may be combined in a single valve for example as an Figs. 8 and 10. In Fig. 10 a disc 40 can be moved in a chamber 41 towards and away from a port 42 open to an inlet passage 43. When closed the disc 40 seats on concentric O-rings 45, 46 between which there is a space 47 connected to the valve test means by a passage 48. In Fig. 10 a slide 64 is slidable between a slipper 65 and two concentric seals 66, 67, seated to a valve casing 60 as by O-rings 68, to interconnect inlet and outlet passages 62, 63 by way of a passage 69 in the slide 64 (shown open in Fig. 10). A passage 72 connects the annular space 71 between the seals to the valve testing means A third valve type (Fig. 9, not shown) comprises a spherical plug (50) rotatable in a spherical body (51) such that in one position a passage (52) in the plug (50) interconnects inlet and outlet passages (53, 54). Passages (57, 58) interconnect the passage (52) and the valve testing means.