1. (a) Regenerators shall be constructed, installed and operated so that at all times the pasteurized product in the regenerator will automatically be under greater pressure than the raw product in the regenerator.
2. (b) The pasteurized product, between its outlet from the regenerator and the nearest point downstream open to the atmosphere, shall rise to a vertical elevation of 12 inches above the highest raw product level downstream from the constant-level tank, and shall be open to the atmosphere at this or a higher elevation.
3. (c) The overflow of the top rim of the constant-level raw product tank shall always be lower than the lowest product level in the regenerator.
4. (d) No pump or flow-promoting device which can affect the proper pressure relationships within the regenerator shall be located between the pasteurized product outlet from the regenerator and the nearest downstream point open to the atmosphere.

5. (e) No pump shall be located between the raw product inlet to the regenerator and the raw product supply tank unless it is designed and installed to operate ony when the product is flowing through the pasteurized product side of the regenerator and the pressure of the pasteurized product is higher than the maximum pressure produced by the pump. This may be accomplished by wiring the booster pump so that it cannot operate unless:

   1. (1) the metering pump is in operation;
   2. (2) the flow-diversion device is in forward-flow position; and

   3. (3) the pasteurized product pressure exceeds, by at least 1 psi, the maximum pressure developed by the booster pump.

      Pressure gauges shall be installed at the raw product inlet to the regenerator and at the pasteurized product outlet of the regenerator or the outlet of the cooler. The accuracy of required pressure gauges shall be checked by the regulatory agency upon installation, quarterly thereafter, and following any repair or adjustment.

6. (f) The motor, casing and impeller of the booster pump shall be identified and a record of that information maintained as directed by the regulatory agency. All electric wiring shall be in permanent conduit except that rubber-covered cable may be used for final connections.
7. (g) All raw product in the regenerator shall drain freely into the constant-level raw product tank when the raw product pump(s) are shut down and the raw product outlet from the regenerator is disconnected.

8. (h) When vacuum equipment is located downstream from the flow-diversion device, means shall be provided to prevent the lowering of the pasteurized product level in the regenerator during periods of diverted flow or shutdown. An effective vacuum breaker and an automatic means of preventing a negative pressure shall be installed in the line between the vacuum chamber and the pasteurized product inlet to the regenerator.

   Note:

   See Appendix 3 of this Title for further discussion concerning methods of achieving the required pressure relationships within the regenerator.

Pasteurizers employing product-to-product regenerative heating with both sides closed to the atmosphere shall comply with the following: