The Hydro-Pro water system tanks by Goulds Pumps feature deep-drawn steel shells providing maximum material strength. The tanks also contain an inner shell, which prevents the diaphragm from over-expanding. The rubber-made diaphragm tanks separate air and water while maintaining air charge. Standard models feature an interior polypropylene tank liner. Mounted pump models feature an interior fusion-bonded polymeric lining. All standing and in-line buried models have a stainless steel system connection. The tanks have a maximum working pressure of 125 psi (except mounted pump models, which have 100 psi) and a temperature maximum of 120 F. Goulds Pumps,