47. Drain Cocks.
a. Five brass drain cocks, each with a lever handle and of 1⁄2-inch bore, are to be provided, and located one on each end of each water cylinder, and one above the upper valve deck.
Care should be taken to select a pattern of cock whose passageway is the practical equivalent of a 1⁄2-inch hole. Some patterns of 1⁄2-inch commercial cocks although threaded for 1⁄2-inch pipe thread have but a 1⁄4-inch hole through them. Such are not acceptable.
FOOTNOTE:
[D] Such detachable rubber check valves are now made up in regular form by the George F. Blake Mfg. Co., East Cambridge, Mass.
TESTS FOR ACCEPTANCE.
48. Test for Smoothness of Action.
a. Provide outlets for the water; start the pump slowly, gradually open steam-throttle to bring the pump to full speed.
The pump should run smoothly at the rated full speed of 70 revolutions per minute (or 60 revolutions if a 1,500-gallon pump) with full length of stroke, and meanwhile maintain a water pressure of 100 lbs. per square inch.