_a._ Four brass drain cocks, each with lever handle and of one-half
inch bore, are to be provided, and located one on each end of each
steam cylinder.
Care should be taken to select a pattern of cock whose passageway is
the full 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.