46 CFR 134.180: Piping for fire-main suction.

(a) Except as provided by paragraph (b) of this section, suction lines must comply with § 132.110 of this subchapter.

(b) Suction lines that extend below the main deck outside the hull plating and that supply the fire pump with the liftboat in the elevated mode must be metallic, unless they comply with § 56.60-25(c) of this chapter for vital fresh-water and salt-water service, except that they may be of unlimited length.