Two embodiments of a normally closed asymmetric tapered fitting valve are disclosed. Each tapered fitting valve comprises a single molded incompressible, but supple part and a skeletal support whereby the tapered fitting valve is opened by insertion into a correspondingly sized female tapered fitting. Use of the valve specifically targets use with medical luer fittings, but is not limited thereto. The preferred embodiment of an actuator portion of the valve has dimensions which are identical those of a female tapered fitting into which the valve is inserted to open. The valve opens by compressing a slit which is disposed along a major axis of the asymmetric valve as it is advanced through a tapered circular duct. The valve has back-to-back closure features which maintain the valve closed when not inserted. A stand-alone male adapter comprising the tapered fitting valve is disclosed. Also, a syringe barrel comprising a skeletal support structure for a securely affixed valve to thereby provide a syringe barrel with an integrally affixed male adapter is also disclosed.