Excerpt from 1000 Practical Air Brake Questions and Answers for Railroad Men Q. Is the 8-inch a single or double acting pump? A. Double acting. Q. What do we mean when we say a double acting p'ump A. A pump that compresses air on both up and down stroke. Q. How are the receiving and discharge valves located cylinder though in two separate cages, one above the other. Q. Which is the receiving valve 'in each cage? A. The lower valve. Q. 'are the receiving and discharge valves in an 8 - inch pump of the same size? A. No; the receiving valves are the smaller. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.