Chicago House Wrecking Company · Chicago House Wrecking Company · leaf 29
combination water column, on which this water glass is connected; also asafety valve and a drain cock for blowing out the water in the boiler atany time. We also provide a check valve to be~\ placed on the return main as shown in ■-» Fiirnrp. 7fi. « Figure 78.The purpose of this check valve is to
