FIG. 1. NO. 6 DISTRIBUTING VALVE AND DOUBLE CHAMBER RESERVOIR. Technical Contributions for this department must be received by the Editor on or before the 12th of the month to be in time for the succeeding issue. Westinghouse No. 6 E-T Equipment— BY T. F. LYONS. Q. What is the duty of the distributing valve? A. To admit air from the main reservoir to the locomotive brake cylinders when applying the brake, to exhaust the air from the brake cyl- MR. inders when releasing the brake, to automatically maintain the brake cylinder pressure against leakage and to develop the proper brake cylinder pressure gardless of piston travel. Q. Name the different parts of the distributing valve. re A. Referring to the numbered parts in Figs. 1 and 2. 2. Body. 3. Application valve. cover. 4. Cover screw. 5. Application valve. 6. Application valve spring. 7. Application cylinder cover. 8. Cylinder cover bolt and nut. 9. Cylinder cover gasket. 10. Application piston. 11. Piston follower. 12. Packing leather expander. FIG. 2. NO. 6 DISTRIBUTING VALVE. 38. Distributing valve drain cock. 39. Application valve cover gasket. 40. Application piston cotter. 41. Distributing valve gasket (not shown). 42. Oil plug. 43. Safety valve air strainer. 44. Equalizing piston graduating sleeve. 45. Equalizing piston graduating spring nut. 46. Equalizing piston graduating spring. FIG. 3. RELEASE AND CHARGING POSITION. 24. Cylinder cap bolt and nut. 25. Cylinder cap gasket. 26. Equalizing piston. 27. Equalizing piston packing ring. 28. Graduating valve. 29. Graduating valve spring. 31. Equalizing valve. 32. Equalizing valve spring. 33. Lower cap nut. 34. Safety valve. 35. Double chamber reservoir. Q. To what is the distributing valve attached? A. To the distributing valve reservoir or double chamber reservoir. Q. How many chambers has the distributing valve reservoir? A. Two- pressure chamber and application chamber. Q. Name the different pipe connections to the distributing valve reservoir. A. Referring to the lettered and numbered parts in the different cuts: MR, Main reservoir pipe. IV, Distributing valve release pipe. II, Application cylinder pipe. CYLS, Brake cylinder pipe. BP, Brake pipe. Q. To what do these different pipes connect? A. The supply pipe, which is the upper pipe on the left, connects the distributing valve with the main reservoir pipe. The application cylinder pipe, which is the middle pipe on the left, connects the application cylinder of the distributing valve with the automatic and independent brake valves. The distributing valve release pipe, which is the lower pipe on the left, connects the application cylinder exhaust port in the distributing valve with the independent brake valve, and through it, when in pressure chamber and application cylinder and chamber is practically the same as that of an auxiliary reservoir and brake cylinder, it will be understood that one pound from the pressure chamber will make 2 pounds in the application cylinder and chamber; in other words, with the pressure chamber charged to 70 pounds and no pressure in the application cylinder or chamber, if they were connected and allowed to re-equalize they would do so at about 50 pounds; that is, 20 pounds from the pressure chamber would make 50 pounds in the application chamber and cylinder. FIG. 5. SERVICE LAP. cation chamber and cylinder, also closing port e, which leads to the safety valve, Fig. 5. Q. Where is the application cylinder iocated? A. At the left of the application piston 10. Q. Upon what does the amount of pressure in the application cylinder and chamber depend, when making an automatic service application of the brake? A. On the amount of brake-pipe reduction; and as the relative volume of the Q. How is the application piston 10 affected by the air pressure in the application cylinder g? A. Pressure forming in this cylinder will force the piston to the right. Q. When the application piston moves to the right, what takes place? A. The piston in moving to the right will carry with it the exhaust valve 16, closing the exhaust ports e and d, at the same time moving the application valve 5, opening the supply port b allowing main reservoir from chamber q to flow through ports b and c to the connection marked CYLS, and on to the different brake cylinders on the locomotive. Q. How long will the air continue to flow to the brake cylinders? A. Until the pressure in the brake cylinders and chamber b at the right of the application piston 10 becomes slightly greater than that in the application cylinder g, when the piston will move back, carrying the application valve 5 with it, just far enough to close port b or to lap position, figure 5. The piston is assisted in its movement by the graduating spring 20, which was compressed when the valve moved to application position. Q. With the application valve 5 in lap position, if there be brake-cylinder leakage will the locomotive brake leak off? A. No. Q. Explain why. A. Any drop in brake-cylinder pressure will be felt in chamber b at the right of the application piston 10, causing a difference in pressure on the two sides of the piston, thus allowing the pressure in the application cylinder to move the application piston 10 and application valve 5 to the right, again opening the supply port b, allowing main-reservoir air to flow from chamber a to the brake cylinders until the pressure is again slightly greater than that in the application cylinder g, when the application MR this way air will be sup- Q. What effect will the piston travel have on the pressure developed in the brake cylinder? A. None; as the pressure in the brake cylin pipe side of the equalizing piston 26; this increase of pressure above that on the left or pressure chamber side of the piston will cause the piston to move toward the left, carrying with it the graduating valve 28 and equalizing valve 31 to release position, or until cavity k in the equalizing valve registers with ports w, h and i. Q. When the equalizing valve 31 is in release position what takes place? ders is dependent entirely on the pressure in the application cylinder, which is not affected by the piston travel. Q. Explain the movement of the parts in the distributing when the automatic brake valve is moved to release position, after an automatic application of the brake. A. In release position, air from the main reservoir flows direct to the brake pipe, causing a rise of pressure which is felt in chamber p on the right or brake FIG. 6. EMERGENCY. A. This allows air from the application cylinder g and application chamber to flow to the distributing valve release pipe IV and on through the independent brake valve to the automatic brake valve, where the port to which this pipe leads is blanked by the automatic rotary valve, which prevents the air from leaving the application cylinder and application chamber, thus holding the locomotive brake applied while the train brakes are being released. Q. Is the action similar where the |