ASTM F991-86

1.1 This specification provides design, construction, and purchasing criteria for docking/drain plug and boss assemblies.

1.2 Assemblies are intended for installation in shell, rudder, and tank bottom plate from 5/16 through 11/2 in.

1.3 Assemblies shall be installed at the lowest point of a tank or rudder for draining during dry docking or cleaning of tanks.

1.4 The values stated in inch-pound units are to be regarded as the standard.