Abstract: A discharge control system for a reservoir having a pressure-communicating valve in a valve chamber with the inlet of the pressure-communicating valve connected the reservoir outlet aperture and the outlet of the pressure-communicating valve connected to a discharge aperture in the containment structure for the valve chamber. An auxiliary reservoir outlet aperture enables water to flow from the reservoir into the valve chamber, submerging the pressure-communicating valve. Water flows from the valve chamber through a valve chamber outlet aperture that is substantially the same as the auxiliary reservoir outlet aperture and is located at substantially the same height as the center of the reservoir outlet aperture. One or more supplemental auxiliary reservoir outlet apertures are located at incrementally greater heights in the containment wall for said reservoir to assure that water will enter and leave the valve chamber at the same rate under all conditions.

Abstract: A valve seat for a valve used with a treater tank comprising a body having a generally cylindrical bore threthrough, the body having a first end, a second end and being made of metal, the first end having a counterbore concentric with the cylindrical bore, the body having means on the second end for mounting the valve seat in the valve and an insert carried by the body and received in the first end, the insert being comprised of an erosion-resistant synthetic polymeric material having a cylindrical passageway therethrough, the insert having a first portion defining first inner and outer concentric cylindrical surfaces, the first outer surface having a diameter greater than the diameter of the counterbore, an annular sealing surface being formed on the first portion, and a second, generally cylindrical portion, said second portion being received in the counterbore and means disposed between the body and the second portion to secure the insert to the body and effect fluid-tight sealing between said insert and s