How long Thomas Messenger continued manufacturing his valves is uncertain. He certainly continued endeavouring to perfect his valve design as he successfully patented another two designs, one in 1876, another in 1881. He then appears to have moved onto trying to improve pipe connections, again successfully submitting two patent applications, one in 1885 and another, his last, as late as 1895, when he was in his late 60s. He even spent time trying to design another boiler, although the patent application failed.
In 1876, he described himself as a mechanical engineer, in 1881 was a valve manufacturer but by 1885 as simply an engineer or civil engineer, a term he continued to use until his last patent application in 1895.