National boilers, radiators, and specialties: catalog no. 26 (1920)
National Radiator Company · National Radiator Company · leaf 64
Automatic airvalves are indispen-sable factors in aheating plant andplay such an im-portant part thatthe use of cheaplymade air valves area serious menace tothe steam fitter aswell as to the owner. Solus Perfect Valve sideraS ^^^^^^l^^U^^ ™ *■&. • ***** con-air valve at a reasonable price P y°U…
