Abstract: A plug valve having a modular construction. The valve has a solid, single-piece body with two opposed openings interrupted by an internal chamber. The chamber houses a rotatable plug which selectively restricts or allows flow from one of the two openings to the other. Inserts partially surround the plug and have openings that corresponds to openings in the valve body and the plug. A seat with an end surface corresponding to each insert extends partially within each opening. A bolted-on flange extends from each side of the valve and has an internally placed sleeve which defines the flow path through the valve. The sleeve may seal against the seat at one of its ends. A non-planar groove may be formed in the end surface of each seat to seal the opening against each insert.

Abstract: A plug valve having a modular construction. The valve has a solid, single-piece body with two opposed openings interrupted by an internal chamber. The chamber houses a rotatable plug which selectively restricts or allows flow from one of the two openings to the other. Inserts partially surround the plug and have openings that corresponds to openings in the valve body and the plug. A seat with an end surface corresponding to each insert extends partially within each opening. A bolted-on flange extends from each side of the valve and has an internally placed sleeve which defines the flow path through the valve. The sleeve may seal against the seat at one of its ends. A non-planar groove may be formed in the end surface of each seat to seal the opening against each insert.