The United Association of Plumbers, Steamfitters, Refrigeration & HVAC Service Technicians Local Union 230 is proud to be the oldest, continuously operating craft union in San Diego — and we are still going strong! United Association Local Union 230 offers a wide range of technical skills that are valued throughout the construction industry. Our members are the piping professionals that provide the San Diego Community with the complex piping systems that are responsible for potable water, sanitary systems, medical gas, heating, cooling, and purity piping for the pharmaceutical and micro-electronic industries along with an array of other services that help make San Diego America’s Finest City.