In embodiments, a gate valve includes a valve body including a flow passage from a first opening to a second opening, and a gate channel having a first end intersecting the flow passage and a second end delineated by a third opening. A valve cover fits over the third opening. A cap fits over a valve cover opening. In embodiments, a valve cover includes a body with a second sealing surface protruding from a first sealing surface, both around an opening of the body. A cap has a third sealing surface to mate with the first sealing surface, and a fourth sealing surface congruent to the second sealing surface. In embodiments, a valve cover cap includes a body with a first sealing surface on an end of a wall. Pin flanges each have a pin hole having a pin hole axis oriented perpendicular to a center axis of the wall.