Abstract: A foot-operated valve has a valve housing formed with a longitudinal bore which includes a front section and a rear section that has an internal diameter wider than that of the front section to form a shoulder which serves as a valve seat therebetween. The longitudinal bore has an open front end and a closed rear end. A valve stem extends into the longitudinal bore and is provided with a valve disc which is disposed in the rear section of the longitudinal bore. A valve stem has a front portion which extends sealingly through the open front end of the longitudinal bore. The valve disc is biased to abut normally against the valve seat so as to block normally communication between the front and rear sections of the longitudinal bore. A base has the valve housing secured thereon. The base is provided with an upwardly extending mounting seat disposed adjacent to the valve housing and formed with a cylindrical hole that is aligned with the valve stem.