The disclosure is of a ball check valve comprising a valve body with a flow passageway completely through it. The flow passageway is counterbored at one end to form a conical seat and at the other end to form a radial shoulder. The valve member comprises an integral ball and stem of an elastomer. The stem is inserted through the valve passageway and stretched to function in the nature of a tension spring, with lateral extensions on the stem seated against the radial shoulder of the valve body.