THE WORTHINGTON DUPLEX PUMP.
The illustrations,Figs. 302and303, are sectional views of one side, or half, of the Worthington steam pump, showing two different designs. They illustrate the interior arrangement of the pump. The valve, as may be seen at, E, is an ordinary slide valve; the motion of this valve is controlled by a vibrating arm, F, which swings through the whole length of the stroke. The moving parts are always in contact, which ensures smooth and even motion.
This valve motion is the prominent and distinguishing characteristic of the Worthington duplex pump.Two steam pumps are placed side by side and so combined that one piston acts to give steam to the other, after which it finishes its own stroke and waits for its valve to be acted upon by the other pump before it can renew its motion. This pause allows the water valves to seat quietly, and removes any harshness of motion. As one or the other of the steam valves is always open, there is no dead point, and therefore the pump is always ready to start when the steam is admitted.
Fig. 304.
Fig. 304.
In the plunger and ring pattern,Fig. 302, there is a double-acting plunger, B, working through a deep metallic ring bored to fit the plunger. The plunger is located some inches above the suction valves, leaving asettling chamber, into which any foreign substance may fall out of the way of the wearing surfaces. Both the plunger and ring can be taken out and either refitted or, when necessary, renewed. The valves consist of small discs of rubber, or other suitable material, and are easily accessible through convenient handholes. This pattern is recommended where the liquid to be pumped contains small quantities of grit or foreign material, or where there is an unusually long or high suction lift.
In the piston-pattern pump,Fig. 303, there is a packed water piston, G, working in a brass-lined cylinder, H. Both the suction and the discharge valves are located above the water pistons, so that the pistons may be at all times submerged. This pattern is recommended where the liquid to be pumpedcontains no grit or foreign material.
Fig. 304shows the Worthington Admiralty pattern boiler feed pumpwhich is designed to meet the requirements of the United States Bureau of Steam Engineering for steam boiler pressure up to 250 lbs. to the square inch. The ordinary slide valves are replaced by piston valves with outside, adjustable, lost-motion links, making it possible to readily adjust the stroke. The water end is made of composition, gun metal, or cast-iron, as desired. When made of cast iron the water end is brass-fitted throughout.
Table of Sizes, Capacities, Etc.
Diameter ofSteamCylindersDiameter ofWaterPistonsLengthofStrokeHorse-powerof Boiler basedon 45 pounds ofwater per hour,which thispump willsupply atslow speed.41⁄223⁄4417051⁄431⁄25280646470641⁄2659071⁄25667096696071⁄241⁄210800961014001071022001281⁄21032001291⁄41038001410154800Diameter ofSteamCylindersDiameter ofWaterPistonsLengthofStrokeSizes of Pipes forShort LengthsTo be enlarged aslength increases.SteamPipeExhaustPipeSuctionPipeDeliveryPipe41⁄223⁄443⁄411⁄42251⁄431⁄25111⁄221⁄221⁄264611⁄2243641⁄2611⁄224371⁄25611⁄2254966221⁄25471⁄241⁄21011⁄22439610221⁄25410710221⁄2651281⁄21021⁄23651291⁄41021⁄236614101521⁄2386Diameter ofSteamCylindersDiameter ofWaterPistonsLengthofStrokeApproximate SpaceOccupiedInchesHeightDepthWidth41⁄223⁄4438182351⁄431⁄25462229646502332641⁄2650233271⁄25654283396657273671⁄241⁄2106628339610682736107107734401281⁄2108639441291⁄4108639441410151103650
A notable feature in this pump is the location of the exhaust passage;this opening is underneath the cradle—or the part that the pump rests upon—just forward of the steam cylinders. The flanges of the steam end and cylinders and the steam chest cover have been made heavier than the regular and strengthened to withstand the higher pressures.
Fig. 305is a sectional view of a larger size duplex pump than the one shown inFig. 302. The plunger, B, packing is identical, but the number of water valves is double; access for cleaning the suction chamber, C, is had by removing the hand hold plate at the side and in the center. The discharge valves are reached through the hand hold at D.
Fig. 305.
Fig. 305.