SAND IN THE PUMP-CHAMBERS.
The pump has one arch-enemy, which comes off victor in every conflict. That is sand. The railway idiom which uses the word “sand” to express courage, originated in the knowledge of how certainly and quickly a handful of sand would vanquish the best pump that mechanical skill might produce. The grit works its way among the packing, and tears and cuts the plunger out of shape: it insinuates itself up between the cages and valves, and holds the latter so fast that hard hammering is often needed to dissolve the compact. Proper washing out of the tank, cleansing of feed-pipes, and the use of water free from sand, is the only sure remedy for this evil. Where an engineer is situated so that he must take water containing sand in suspension, partial relief will be obtained by giving the valves free side-room in the cages; but an injector will be found much superior to a pump as a means of putting sand-contaminated water into a boiler.