Copper lines have virtually no stiffness or mass.
Bronze Hose & Braid w/ Copper Sweat Ends 2 x 18 metallic flexible hoses reduce pipe wall noise transmission, prevent pipe fatigue, simplify alignment problems and reduce equipment flange stress. Not suitable for steam. Hoses are manufactured with bronze hose covered by a tightly woven bronze braid. Braided bronze hose with copper sweat ends are designed for all services except refrigerant.