A valve assembly configured to be mounted on a support structure comprises a flowbody having a first port, a second port, and a flow passage there between. A flange is coupled around the flowbody proximate the first port. A sleeve extends into the flowbody through the first port, and a radial lip is coupled to the sleeve proximate the first port. A retaining ring is coupled to the flange and configured to confine the radial lip between the retaining ring and the support structure to secure the sleeve within the flowbody when the valve assembly is mounted on the support structure.