pressure stop will raise both pressures to the required amount. Directly, the readjustment of the feed valve raises the brake-pipe pressure to 110 pounds; indirectly, it raises main-reservoir pressure to 130 pounds, because the increase of brake-pipe pressure equally increases the air pressure upon the diaphragm of the excess-pressure governor top: 110 pounds (brake-pipe pressure), plus 20 pounds (spring pressure), equals 130 pounds, the regulating power of excess-pressure governor top, High-Speed Brake.

(Where there is a possibility of having to change from the 70-pound brake to the High-Speed Brake, the high-pressure-right-hand-governor top should not be set at less than 140 pounds, in order that it may operate at a higher figure than the High-Speed pressure adjustment of the excess-pressure top.)

Another important feature is that before commencing, and during, the descent of steep grades, this governor enables the engineer to raise and maintain the brakepipe pressure about 20 pounds above the feed-valve regulation, merely by the use of release position of the automatic brake-valve, the position which should be used during such braking.

While the turning of adjustment nut 18 will increase or decrease the maximum pressure that can be obtained in the main reservoir, remember that turning adjusting nut 26 increases or decreases the amount of

Adjustment of Pump Governor

excess pressure that will be regularly carried; and that in running and holding positions of the automatic brake-valve the location of both hands on the large duplex gauge is governed by the adjustment of the feed valve; but that spring 27 in the excess-pressure governor top keeps the two gauge hands 20 pounds apart.

Copyright, 1909, by The Norman W. Henley Publishing Co.

THE COMBINED AIR STRAINER AND CHECK-VALVE.

With the advent of the No. 6 E-T equipment, the COMBINED AIR STRAINER AND CHECK-VALVE illustrated in Fig. 46 is furnished as a part of the locomotive-brake equipment, whether specified by the purchaser or not; and, if the Train Air Signal is to be used, two of these are furished. A 3-inch cut-out cock is also supplied to be used in connection with each.

In the ordinary automatic equipment the locomotive braking power is supplied from the brake pipe (train line), and the brake on a dead engine is automatically operative the same as any car brake. In the E-T equipment, however, while it is automatically operated through the brake-pipe air, locomotive braking pressure must be taken directly from the main reservoir: One application of the COMBINED AIR STRAINER AND CHECKVALVE is as the DEAD-ENGINE FEATURE, by which air from the brake pipe is supplied to the main reservoir of a dead engine, or one whose air pump is inoperative said engine being in tow-and this is an important adjunct to the E-T locomotive-brake equipment.