Premolded gasket joints for hub and plain end cast-iron soil pipe
shall be used and shall be a neoprene compression-type gasket which
provides a positive double seal in the assembled joint. The gasket
shall be a premolded one-piece unit, designed for joining the cast-iron
hub and plain end soil pipe and fittings. The assembled joint shall
be sealed by compression of the gasket between the exterior surface
of the spigot and the interior surface of the hub. The joint shall
be assembled following the manufacturer's recommendations, using
acceptable lubricant and special pipe-coupling tools designed for
that purpose. The plain spigot end shall be forced into the hub end
of the pipe for the full depth of the hub itself. Lubricant shall
be a bland, flax base, nontoxic material and shall not chemically
attack the gasket material.