Failure to specify the proper control level of hydrate alkalinity in high pressure industrial
boilers has resulted, over the years, in a myriad of problems. In the 1980s, the authors
encountered a high heat flux, moderately high pressure, “process-on-the-tube-side” heat
recovery boiler in a west coast oil refinery that had experienced two failures in quick
succession. Several different mechanisms had been proposed to explain the failures. Caustic
gouging was strongly suspected in the case of the first failure. While reviewing the available
literature during the process of formulating an internal chemical treatment program and control
regime, the authors uncovered a particularly compelling previously published paper that
appeared to have been largely forgotten by the industry. This work was used as the basis for
specifying hydrate alkalinity control in this system, with great long term success.