Chicago Fittings Corporation certifies that all Sealastic™ Gas Fittings manufactured with loose stiffeners, when installed per Chicago Fittings installation instructions, will meet all applicable requirements defined under D.O.T. 192.238(b), ASTM D2513 Category 1, ASTM F1973, ASTM F1948-99a Category 1 and NFPA 54 (ANSI Z223.1). The loose stiffeners must be manufactured or approved by Chicago Fittings to adhere to these requirements. Should a stiffener not be manufactured or approved by Chicago Fittings, it will be the responsibility of the operating utility or end user to assure they adhere to the above defined standards.