GB191303453A - Improvements in and relating to Pumping Systems. - Google Patents

Abstract

3453. Rosencrans, H. F. Feb. 10. Regulating delivery by by-passes.- Relates to automatic and electrically-operated means for operating a valve in a bypass, in connexion with a pump, for the purpose of maintaining the pressure in water mains between certain predetermined limits, and further relates to means for altering these limits, for example in the event of fire. The pump 11, Fig. 1, draws from a supply pipe 10 and supplies to the mains 14 preferably through a surge tank 13 ; but when the pressure in the tank rises above or falls below certain limits, the by-pass valve 19 is automatically opened or closed respectively, and in the former case the pump simply forces water through the by-pass. Solenoids 27, 28, working in conjunction with a dash-pot 29, are used for operating the valve 19 and one or the other of these is energized by the throwing over of a switch 35, in circuit with a transformer 41, by the energizing of one of two solenoids 31, 32, also in circuit with the transformer 41, and with a switch 75, which is operated by changes of pressure in the tank 13. The switch-arm 75 is connected by gearing to the end of a Bourdon tube 52, which communicates through a pipe 51 with the tank 13, and thus, when certain superior or inferior limits of pressure are reached, contact is made with the terminal 67 or 66 respectively. The terminals 66, 67 are connected to metallic insulated rings 62, 63, Fig. 3, which may be rotated when it is desired to alter the pressure limits, and for this purpose a portion of the casing, Fig. 3, may be mounted on ball bearings 57 in the fixed member 48, and a sprocket-wheel 89, attached to the movable member, is rotated by the closing of a switch 106, when an alarm of fire is given. The closing of the switch 106 energizes a solenoid 92 working with a dash-pot 94, and at the same time a signal is conveyed to the pumping-station that more pumps may be required. Fig. 7 shows an alternative form in which a pressure cylinder 120 and piston 122 replace the Bourdon tube. The piston-rod carries collars 125, 126 for making and breaking the circuits of the solenoids 31, 32. A spring 129, against which the piston acts, is shortened and therefore strengthened by the energizing of an adjustable solenoid 132 through the closing of a switch 106 when an alarm of fire is given. A pilot light 109 in the pumping-station is simultaneously lighted. The limits of the domestic pressure may be adjusted by sliding the collars 125, 126 upon the piston-rod, or by altering the position of screws 142, and the fire pressure by means of the screws 142 or by raising or lowering the solenoid 132.