theksmith 5,778 Posted August 15 Our trailer has a black water flush/rinse connection. The plumbing that it routes through includes the common "vacuum breaker" style check valve to prevent accidentally back-flowing from the black tank into the hose and water supply. Apparently these are known to be rather delicate and not last long. Reviews for the brass versions aren't really any better than the all plastic ones. My question is, why is this vacuum breaker style used in this application instead of a simple spring based one-way check valve? Thanks! Share this post Link to post Share on other sites