Abstract: A manifold for use with a tank in acid service includes a cylindrical main body having a central longitudinal axis, a tank connection and a plurality of parallel outlet connections in fluid communication with the cylindrical main body. The outlet connections are spaced apart at equal intervals along the main body and extend perpendicular to the central longitudinal axis of the main body. The cylindrical main body, the tank connection and outlet connections are each fabricated from a high density polyethylene having a density of from 0.956 to 0.964 gm/cm3. In one aspect, the manifold is fabricated from a high density polyethylene having a melt index of <0.15 gm/10 min., a flexural modulus of 110,000 to 160,000 psi and a tensile strength of >3600 psi. The high density polyethylene has a slow crack growth rate of >1000 hours, environmental stress cracking rate of >5000 hours.