June 1, 1917.] 



THE INDIA RUBBER WORLD 



515 



The discharge water passes from the right trunnion in the direc- 

 tion of the short arrows to the discharge valve B ; the same trun- 

 nion is used for the inlet and discharge water. In operation the 

 water to be handled is returned to a receiver and flows by 

 gravity to the bowl of the trap through a check valve. When 

 the bowl is full of water it tilts to its lowest position, which ac- 

 tion opens the steam and discharge valves. Live steam, there- 

 fore, rushes into the bowl and the water, being under steam 

 pressure, is forced out through the inlet passage, but, being pre- 

 vented from returning to the receiver by the check valve, passes 

 through the upper part of the yoke, the discharge valve and the 

 discharge pipe. 



As soon as the water has been discharged from the bowl the 

 weight brings it back to the tilling position, which action closes 



the steam and discharge 



valves, when the cycle of fill- 

 ing and discharging is re- 

 peated. 



The Morehead design of 

 tilting return traps is shown 

 in Fig. 13. This trap receives 

 water of condensation and 

 automatically delivers it to 

 the boiler at practically the 

 temperature due to the pres- 

 sure at which the steam is 

 condensed. The steam pres- 

 sure is admitted to the sur- 

 face of the water in the trap 

 and is automatically shut off 

 before the trap tank is empty. 



Fig. 11. 



Tilting Tr.\p. 



The steam used is only such as 

 is condensed by the latent heat passing from it to the water in 

 the tank and all is returned to the boiler. 



Referring to Fig. 13, the water enters the trap through the 

 inlet pipe in the direction of the arrows pointed toward the 

 center through the w-ater end of the trunnion A. The opposite 

 trunnion holds the steam admission valve which regulates the 

 steam supply. The tank is counterbalanced by a cast-iron 

 counterpoise weight on the end of a wrought-iron lever. At the 



point of application of this 

 valve lever to the tank, an 

 extension rod engages with a 

 lever controlling the steam 

 valve. 



Just under the ends of the 

 tank are two upright buffers 

 which limit the swing of and 

 provide resting points for the 

 trap in its filling and dis- 

 charge position, thus remov- 

 ing all weight from the trun- 

 nion packing. 



The trap tank is maintained 

 in a horizontal position by 

 the weight lever, and when 

 sufficient water has entered 

 the trap to overcome the ac- 

 tion of the lever, the tank 

 will tilt downward, automat- 

 ically opening the live-steam 

 valve, admitting steam at 

 boiler pressure above the water. The pressure in the tank 

 then forces the water out of the rear connection through the 

 water trunnion and discharge pipe to the boiler. When the 

 tank is relieved of water the weight tilts it back to its original 

 position, and the filling and tilting action is repeated. 

 VACUUM TR.\r.S. 

 Vacuum traiis are used for drying vacuum lines or any ap- 



FiG. 12. .\rr.\ngement of 



Trunnions .\nd V.-\lves. 



BUNDY Tr.\p. 



Fig. 13. Morehe.jvd Tiltixg Tr.\p. 



paratus working under a vacuum. The Detroit vacuum trap, 

 shown in Fig. 14, is always placed at the low point of the heat- 

 ing system and receives the condensation by its vacuum, lifting 

 it to the return trap on top of the boiler. In operation, when 

 the vacuum trap fills it 

 tilts downward, the live 

 steam valve is opened, 

 which allows a pressure 

 on the trap above the 

 water. This pressure 

 forces the condensation 

 up to the return trap on 

 top of the boiler. This 

 upper trap receiving the 

 water, fills and tilts for- 

 ward, opening the live 

 steam valve. Thus the 

 trap pressure being equal 

 to the boiler pressure, 

 the water by the law of 

 gravity flows into the 

 boiler, due to its posi- 

 tion several feet above 

 the water line. When the traps have emptied they automatically 

 return to a filling position, closing the live steam valve and 

 opening the air vent valve on the upper trap and the cold water 

 valve on the vacuum trap. 



Another vacuum trap, known as Winter's, is illustrated in Fig. 

 IS. One end of the trap body is fitted with a removable head 

 and secured by bolts, as shown. Connected to the top of the 

 trap is a swing check-valve C, opening toward the trap, h dis- 

 charge pipe carrying an outlet check-valve D, which swings away 

 from the trap, is connected to the bottom. In the chamber below 

 the pipe A'' is a bronze bushing L, containing a piston valve A. 

 Internal ports ape so placed in the valve chamber that they 

 communicate with two sets of radial ports B and G. in the bush- 

 ing, the port M being in communication with the pipes N and O. 



The pipe N 

 connects with 

 the pipe to be 

 drained, and O 

 with the atmos- 

 phere. 



The piston 

 valve is at- 

 tached to one 

 end of a valve- 

 stem, the move- 

 ment of the 

 valve being lim- 

 ited in one di- 

 rection by the 

 liead of the 

 hushing, and in 



the other direction by a socket nut screwed on the valve-stem and 

 working in a socket, as shown, at the right of the adjustable disk 

 F : the valve stem also carries the adjustable disk /. 



There are two inward projecting brackets, P and Q, the first 

 supporting a shaft R, upon which is loosely mounted a rocker 

 with which is connected one end of the link S. the other end 

 being connected, by means of a pin at T, on the lever carrying 

 the ball-float K, which imparts a rocking movement to the lever 

 when the water level in the trap varies. On the shaft R a 

 hammer or lever of unstable equilibrium is mounted, the upper 

 end of the hammer having two arms which straddle the valve- 

 stem. The rocker is provided with two toes E and H, which 

 engage the hammer, thus giving the necessary valve movement. 



14. Detroit \'.\cuum Tr.\p. 



