Abstract: A handle assembly mountable on a valve is disclosed. The assembly includes a head having a receptacle engageable with a rotatable shaft on the valve and a grip projecting outwardly from the head to facilitate turning of the head for actuating the valve. An arcuate slot is positioned in the head, the slot having a curvature matched to the arcuate motion of the handle when used to turn the valve shaft. A limit post is attached to the valve and projects through the slot. A jam nut is mounted on the post adjacent to the head. When tightened against the head the jam nut fixes the position of the head relatively to the valve. A bolt is positioned within the slot and retained by a nut. The bolt is movable along the slot to a predetermined position where it can be temporarily fixed by tightening the nut. The bolt acts as a memory stop when it engages the limit post as the head is turned.

Abstract: A flexible, resilient incompressible seal for a butterfly valve is disclosed formed from a loop having a perimeter mounting surface and a perimeter sealing surface with first and second oppositely disposed axial surfaces extend between the perimeter sealing and mounting surfaces. Channels are positioned in the axial surfaces in spaced relation around the seal. The channels extend from the perimeter mounting surface toward the perimeter sealing surface and provide fluid communication to the perimeter mounting surface allowing fluid trapped against the perimeter mounting surface to escape when compressed by the closing of the valve. A void space is positioned in the perimeter mounting surface in the form of grooves or dimples allowing the perimeter sealing surface to deform under compression when the seal is captured within the valve and substantially restrained from deforming.