A SIPHON BREAK AS A BLOCKING VALVE

An experiment was conducted io determine the feasibility of using the breaking of a siphon as a quick-acting means for stopping sodium fiow following a loss of pump power. A 2-in. pipe system with a high-speed free-surface centrifugal pump was used in this investigation. Runs were made with sodium at 500 and 940 deg F, cover gas at various pressures up to 10 psig, and Reynolds numbers up to approximately 360,000. The siphon-break was established as an effective method for rapid flow stoppage; however, a brief reversal of flow follows the initial flow stoppage. An expression for the flow transient following the breaking of the siphon was derived which agreed reasonably well with experimental results. (auth)