Abstract: A nipple-type waterer having a resilient elastomeric plug which functions both as the spring and as the orifice member for regulating flow through the device. The elastomeric plug bears against the head of the valve stem and is threadably seated within the housing and adjustably positioned for varying the resilient closing force imposed on the valve stem. The usual O-ring creates the main seal between the housing and the outer side of the valve stem head. The elastomeric plug also has an annular sealing ridge thereon which creates a second area of sealed engagement with the rear side of the valve stem head.