Test Procedure

This image is a Logic Diagram of a Flow Diversion Device (Leak Detect Valve Stem) for a computer or programmable logic controller (PLC).

• From the start position, if Power "On", the program can go into Inspect, Product, or clean in place Mode.
• In Inspect Mode, if the time is greater than the time required for the flow promoters to stop, a signal is sent to the detect valve solenoid.
• In Product Mode, the following conditions must be met for the system to go into and remain in forward flow:
  • The Temperature must be greater than pasteurization temperature
  • The manual divert must be off

  For the magnetic flow meter system:

  • The flow must be greater than 5% of the maximum (this refers to a loss of signal set point)
  • The flow must be less than the high flow alarm
  • The time must be greater than the legal hold Forward Flow Delay

  As well:

  • The Divert Microswitch must be in forward position and;
  • The time must be greater than the flush time

  If any of these conditions are not met, the detect Valve Solenoid is signalled to divert the flow.

• In clean in place mode, after a delay of greater than 10 minutes, or the time necessary for all flow promoters to stop (if they cannot operate), clean in place programming begins to clean the system. The detect valve solenoid allows the valve to move for cleaning.