US Patent 7237280 Tub overflow assembly

An overflow assembly employs an overflow elbow having an externally threaded cylindrical fitting that extends through the tub overflow opening. An internally threaded retainer nut with integrally molded test cap is threadably engaged over the overflow elbow cylindrical fitting to compress gaskets against both the inside and outside surfaces of the tub. A test cap is integrally molded with the retainer nut and joined to the retainer nut by a thin, breakable connection. An undercut lip on the test cap facilitates use of a prying tool to break the thin connection and remove the test cap after testing of the drain plumbing. A trim cap snaps over the retainer nut to provide a finished appearance to the installed overflow assembly.