(a) Instruments and controls common to different thermal processing systems—(1) Indicating temperature devices. Each retort must be equipped with at least one indicating temperature device that measures the actual temperature within the retort. The indicating temperature device, not the temperature/time recording device, must be used as the reference instrument for indicating the process temperature.

1. (i) Mercury-in-glass thermometers. A mercury-in-glass thermometer must have divisions that are readable to 1 °F (or 0.5 °C) and whose scale contains not more than 17 °F/inch (or 4.0 °C/cm) of graduated scale. Each mercury-in-glass thermometer must be tested for accuracy against a known accurate standard upon installation and at least once a year to ensure its accuracy. Records that specify the date, standard used, test method, and the person or testing authority performing the test must be maintained on file by the establishment and made available to Program employees. A mercury-in-glass thermometer that has a divided mercury column or that cannot be adjusted to the standard must be repaired and tested for accuracy before further use, or replaced.
2. (ii) Other devices. Temperature-indicating devices, such as resistance temperature detectors, used in lieu of mercury-in-glass thermometers, must meet known, accurate standards for such devices when tested for accuracy. The records of such testing must be available to FSIS program employees.

3. (2) Temperature/time recording devices. Each thermal processing system must be equipped with at least one temperature/time recording device to provide a permanent record of temperatures within the thermal processing system. This recording device may be combined with the steam controller and may be a recording/controlling instrument. When compared to the known accurate indicating temperature device, the recording accuracy must be equal to or better than 1 °F (or 0.5 °C) at the process temperature. The temperature recording chart should be adjusted to agree with, but must never be higher than, the known accurate indicating temperature device. A means of preventing unauthorized changes in the adjustment must be provided. For example, a lock or a notice from management posted at or near the recording device warning that only authorized persons are permitted to make adjustments, are satisfactory means for preventing unauthorized changes. Air-operated temperature controllers must have adequate filter systems to ensure a supply of clean, dry air. The recorder timing mechanism must be accurate.

   1. (i) Chart-type devices. Devices using charts must be used only with the correct chart. Each chart must have a working scale of not more than 55 °F/inch (or 12 °C/cm.) within a range of 20 °F (or 11 °C) of the process temperature. Chart graduations must not exceed 2 °F degrees (or 1 °C) within a range of 10 °F (or 5 °C) of the process temperature. Multipoint plotting chart-type devices must print temperature readings at intervals that will assure that the parameters of the process time and process temperature have been met. The frequency of recording should not exceed 1-minute intervals.
   2. (ii) Other devices. Temperature/time recording devices or procedures used in lieu of chart-type devices must meet known accurate standards for such devices or procedures when tested for accuracy. Such a device must be accurate enough for ensuring that process time and temperature parameters have been met.
4. (3) Steam controllers. Each retort must be equipped with an automatic steam controller to maintain the retort temperature. This may be a recording/controlling instrument when combined with a temperature/time recording device.
5. (4) Air valves. All air lines connected to retorts designed for pressure processing in steam must be equipped with a globe valve or other equivalent-type valve or piping arrangement that will prevent leakage of air into the retort during the process cycle.
6. (5) Water valves. All retort water lines that are intended to be closed during a process cycle must be equipped with a globe valve or other equivalent-type valve or piping arrangement that will prevent leakage of water into the retort during the process cycle.

(v) Vents.

1. (A) Vents must be located in that portion of the retort opposite the steam inlet and must be designed, installed, and operated in such a way that air is removed from the retort before timing of the thermal process is started. Vents must be controlled by a gate, plug cock, or other full-flow valve which must be fully opened to permit rapid removal of air from retorts during the venting period.
2. (B) Vents must not be connected to a closed drain system without an atmospheric break in the line. Where a retort manifold connects several pipes from a single retort, the manifold must be controlled by a gate, plug cock, or other full-flow valve and the manifold must be of a size such that the cross-sectional area of the manifold is larger than the total cross-sectional area of all connecting vents. The discharge must not be connected to a closed drain without an atmospheric break in the line. A manifold header connecting vents or manifolds from several still retorts must lead to the atmosphere. The manifold header must not be controlled by a valve and must be of a size such that the cross-sectional area is at least equal to the total cross-sectional area of all connecting retort manifold pipes from the maximum number of retorts to be vented simultaneously.
3. (C) Some typical installations and operating procedures are described below. Other retort installations, vent piping arrangements, operating procedures or auxiliary equipment such as divider plates may be used provided there is documentation that the air is removed from the retort before the process is started. Such documentation must be in the form of heat distribution data or other documentation from the equipment manufacturer or processing authority. This information must be maintained on file by the establishment and made available to Program employees for review.
4. (D) For crateless retort installations, the establishment must have heat distribution data or other documentation from the equipment manufacturer or from a processing authority that demonstrates that the venting procedure used accomplishes the removal of air and condensate. This information must be maintained on file by the establishment and made available to Program employees for review.

5. (E) Examples of typical installations and operating procedures that comply with the requirements of this section are as follows:

   (1) Venting horizontal retorts. (i) Venting through multiple 1 inch (2.5 cm) vents discharging directly to the atmosphere.

   

   (ii) Venting through multiple 1 inch (2.5 cm) vents discharging through a manifold to the atmosphere.

   

   (iii) Venting through water spreaders.

   

   (iv) Venting through a single 2 1/2 inch (6.4 cm) top vent for retorts not exceeding 15 feet (4.6 m) in length.

   

   (2) Venting vertical retorts. (i) Venting through a 1 1/2 inch (3.8 cm) overflow.

   

   (ii) Venting through a single 1 inch (2.5 cm) side or top vent.

   

6. (3) Batch agitating retorts—(i) Venting and condensate removal. The air in the retort must be removed before processing is started. Heat distribution data or other documentation from the manufacturer or from the processing authority who developed the venting procedure must be kept on file by the establishment and made available to Program employees for review. At the time the steam is turned on, the drain must be opened to remove steam condensate from the retort. A bleeder must be installed in the bottom of the retort to remove condensate during retort operation. The condensate bleeder must be so arranged that the retort operator can observe that it is functioning properly. The condensate bleeder must be checked with sufficient frequency to ensure adequate removal of condensate. Visual checks should be performed at intervals of not more than 15 minutes and the results recorded. Intermittent condensate removal systems must be equipped with an automatic alarm system that will serve as a continuous monitor of condensate bleeder functioning. The automatic alarm system must be tested at the beginning of each shift for proper functioning and the results recorded. If the alarm system is not functioning properly, it must be repaired before the retort is used.
7. (ii) Retort or reel speed timing. The retort or reel speed must be checked before process timing begins and, if needed, adjusted as specified in the process schedule. In addition, the rotational speed must be determined and recorded at least once during process timing of each retort load processed. Alternatively, a recording tachometer can be used to provide a continuous record of the speed. The accuracy of the recording tachometer must be determined and recorded at least once per shift by checking the retort or reel speed using an accurate stopwatch. A means of preventing unauthorized speed changes on retorts must be provided. For example, a lock or a notice from management posted at or near the speed adjustment device warning that only authorized persons are permitted to make adjustments is a satisfactory means of preventing unauthorized changes.
8. (4) Continuous rotary retorts—(i) Venting and condensate removal. The air in the retort must be removed before processing is started. Heat distribution data or other documentation from the manufacturer or from the processing authority who developed the venting procedure must be kept on file by the establishment and made available to Program employees for review. At the time the steam is turned on, the drain must be opened to remove steam condensate from the retort. A bleeder must be installed in the bottom of the shell to remove condensate during the retort operation. The condensate bleeder must be so arranged that the retort operator can observe that it is functioning properly. The condensate bleeder must be checked with sufficient frequency to ensure adequate removal of condensate. Visual checks should be performed at intervals of not more than 15 minutes and the results recorded. Intermittent condensate removal systems must be equipped with an automatic alarm system that will serve as a continuous monitor of condensate bleeder functioning. The automatic alarm system must be tested at the beginning of each shift for proper functioning and the results recorded. If the alarm system is not functioning properly, it must be repaired before the retort is used.
9. (ii) Retort speed timing. The rotational speed of the retort must be specified in the process schedule. The speed must be adjusted as specified, and recorded by the establishment when the retort is started, and checked and recorded at intervals not to exceed 4 hours to ensure that the correct retort speed is maintained. Alternatively, a recording tachometer may be used to provide a continuous record of the speed. If a recording tachometer is used, the speed must be manually checked against an accurate stopwatch at least once per shift and the results recorded. A means of preventing unauthorized speed changes on retorts must be provided. For example, a lock or a notice from management posted at or near the speed adjustment device warning that only authorized persons are permitted to make adjustments is a satisfactory means of preventing unauthorized changes.
10. (5) Hydrostatic retorts—(i) Basic requirements. The basic requirements for indicating temperature devices and temperature/time recording devices are described in paragraphs (a)(1) and (2) of this section. Additionally, indicating temperature devices must be located in the steam dome near the steam/water interface. Where the process schedule specifies maintenance of particular water temperatures in the hydrostatic water legs, at least one indicating temperature device must be located in each hydrostatic water leg so that it can accurately measure water temperature and be easily read. The temperature/time recorder probe must be installed either within the steam dome or in a well attached to the dome. Each probe must have a 1/16 inch (1.6 mm) or larger bleeder opening which emits steam continuously during the processing period. Additional temperature/time recorder probes must be installed in the hydrostatic water legs if the process schedule specifies maintenance of particular temperatures in these water legs.
11. (ii) Steam inlet. The steam inlets must be large enough to provide steam for proper operation of the retort.
12. (iii) Bleeders. Bleeder openings 1/4 inch (or 6 mm) or larger must be located in the steam chamber(s) opposite the point of steam entry. Bleeders must be wide open and must emit steam continuously during the entire process, including the come-up time. All bleeders must be arranged in such a way that the operator can observe that they are functioning properly.
13. (iv) Venting. Before the start of processing operations, the retort steam chamber(s) must be vented to ensure removal of air. Heat distribution data or other documentation from the manufacturer or from a processing authority demonstrating that the air is removed from the retort prior to processing must be kept on file at the establishment and made available to Program employees for review.
14. (v) Conveyor speed. The conveyor speed must be calculated to obtain the required process time and recorded by the establishment when the retort is started. The speed must be checked and recorded at intervals not to exceed 4 hours to ensure that the correct conveyor speed is maintained. A recording device may be used to provide a continuous record of the conveyor speed. When a recording device is used, the speed must be manually checked against an accurate stopwatch at least once per shift by the establishment. A means of preventing unauthorized speed changes of the conveyor must be provided. For example, a lock or a notice from management posted at or near the speed adjustment device warning that only authorized persons are permitted to make adjustments is a satisfactory means of preventing unauthorized changes.
15. (vi) Bleeders and vent mufflers. If mufflers are used on bleeders or vent systems, the establishment must have documentation that the mufflers do not impede the removal of air from the retort. Such documentation must consist of either heat distribution data or other documentation from the muffler manufacturer or from a processing authority. This information must be maintained on file by the establishment and made available to Program employees for review.
16. (c) Pressure processing in water—(1) Common to batch still and agitating retorts—(i) Basic requirements. The basic requirements for indicating temperature devices and temperature/time recording devices are described in paragraphs (a)(1) and (2) of this section.
17. (ii) Pressure recording device. Each retort must be equipped with a pressure recording device which may be combined with a pressure controller.
18. (iii) Heat distribution. Heat distribution data or other documentation from the equipment manufacturer or a processing authority demonstrating uniform heat distribution within the retort must be kept on file at the establishment and made available to Program employees for review.
19. (iv) Drain valve. A non-clogging, water-tight drain valve must be used. Screens must be installed over all drain openings.
20. (2) Batch still retorts—(i) Temperature device bulbs and probes. The indicating temperature device bulbs or probes must be located in such a position that they are beneath the surface of the water throughout the process. On horizontal retorts, the indicating temperature device bulb or probe must be inserted directly into the retort shell. In both vertical and horizontal retorts, the indicating temperature device bulb or probe must extend directly into the water a minimum of 2 inches (or 5 cm) without a separable well or sleeve. In vertical retorts equipped with a recorder/controller, the controller probe must be located at the bottom of the retort below the lowest crate rest in such a position that the steam does not strike it directly. In horizontal retorts so equipped, the controller probe must be located between the water surface and the horizontal plane passing through the center of the retort so that there is no opportunity for direct steam impingement on the controller probe. Air-operated temperature controllers must have filter systems to ensure a supply of clean, dry air.
21. (ii) Crate supports. A bottom crate support must be used in vertical retorts. Baffle plates must not be used in the bottom of the retort.
22. (iii) Stacking equipment. For filled flexible containers and, where applicable, semi-rigid containers, stacking equipment must be designed to ensure that the thickness of the filled containers does not exceed that specified in the process schedule and that the containers do not become displaced and overlap or rest on one another during the thermal process.
23. (iv) Water level. There must be a means of determining the water level in the retort during operation (i.e., by using a gauge, electronic sensor, or sight glass indicator). For retorts requiring complete immersion of containers, water must cover the top layer of containers during the entire come-up time and thermal processing periods and should cover the top layer of containers during cooling. For retorts using cascading water or water sprays, the water level must be maintained within the range specified by the retort manufacturer or processing authority during the entire come-up, thermal processing, and cooling periods. A means to ensure that water circulation continues as specified throughout the come-up, thermal processing, and cooling periods must be provided. The retort operator must check and record the water level at intervals to ensure it meets the specified processing parameters.
24. (v) Air supply and controls. In both horizontal and vertical still retorts, a means must be provided for introducing compressed air or steam at the pressure required to maintain container integrity. Compressed air and steam entry must be controlled by an automatic pressure control unit. A non-return valve must be provided in the air supply line to prevent water from entering the system. Overriding air or steam pressure must be maintained continuously during the come-up, thermal processing, and cooling periods. If air is used to promote circulation, it must be introduced into the steam line at a point between the retort and the steam control valve at the bottom of the retort. The adequacy of the air circulation for maintaining uniform heat distribution within the retort must be documented by heat distribution data or other documentation from a processing authority, and such data must be maintained on file by the establishment and made available to Program employees for review.
25. (vi) Water recirculation. When a water recirculation system is used for heat distribution, the water must be drawn from the bottom of the retort through a suction manifold and discharged through a spreader that extends the length or circumference of the top of the retort. The holes in the water spreader must be uniformly distributed. The suction outlets must be protected with screens to keep debris from entering the recirculation system. The pump must be equipped with a pilot light or a similar device to warn the operator when it is not running, and with a bleeder to remove air when starting operations. Alternatively, a flow-meter alarm system can be used to ensure proper water circulation. The adequacy of water circulation for maintaining uniform heat distribution within the retort must be documented by heat distribution or other documentation from a processing authority, and such data must be maintained on file by the establishment and made available to Program employees for review. Alternative methods for recirculation of water in the retort may be used, provided there is documentation in the form of heat distribution data or other documentation from a processing authority maintained on file by the establishment and made available to Program employees for review.
26. (vii) Cooling water entry. In retorts for processing product packed in glass jars, the incoming cooling water should not directly strike the jars, in order to minimize glass breakage by thermal shock.
27. (3) Batch agitating retorts—(i) Temperature device bulbs and probes. The indicating temperature device bulb or probe must extend directly into the water without a separable well or sleeve. The recorder/controller probe must be located between the water surface and the horizontal plane passing through the center of the retort so that there is no opportunity for steam to directly strike the controller bulb or probe.
28. (ii) Stacking equipment. All devices used for holding product containers (e.g., crates, trays, divider plates) must be so constructed to allow the water to circulate around the containers during the come-up and thermal process periods.
29. (iii) Water level. There must be a means of determining the water level in the retort during operation (i.e., by using a gauge, electronic sensor, or sight glass indicator). Water must completely cover all containers during the entire come-up, thermal processing, and cooling periods. A means to ensure that water circulation continues as specified throughout the come-up, thermal processing, and cooling periods must be provided. The retort operator must check and record the adequacy of the water level with sufficient frequency to ensure it meets the specified processing parameters.
30. (iv) Air supply and controls. Retorts must be provided with a means for introducing compressed air or steam at the pressure required to maintain container integrity. Compressed air and steam entry must be controlled by an automatic pressure control unit. A non-return valve must be provided in the air supply line to prevent water from entering the system. Overriding air or steam pressure must be maintained continuously during the come-up, thermal processing, and cooling periods. If air is used to promote circulation, it must be introduced into the steam line at a point between the retort and the steam control valve at the bottom of the retort. The adequacy of the air circulation for maintaining uniform heat distribution within the retort must be documented by heat distribution data or other documentation from a processing authority, and such data must be maintained on file by the establishment and made available to Program employees for review.
31. (v) Retort or reel speed timing. The retort or reel speed timing must be checked before process timing begins and, if needed, adjusted as specified in the process schedule. In addition, the rotational speed must be determined and recorded at least once during process timing of each retort load processed. Alternatively, a recording tachometer can be used to provide a continuous record of the speed. The accuracy of the recording tachometer must be determined and recorded at least once per shift by the establishment by checking the retort or reel speed using an accurate stopwatch. A means of preventing unauthorized speed changes on retorts must be provided. For example, a lock or a notice from management posted at or near the speed adjustment device warning that only authorized persons are permitted to make adjustments is a satisfactory means of preventing unauthorized changes.
32. (vi) Water recirculation. If a water recirculation system is used for heat distribution, it must be installed in such a manner that water will be drawn from the bottom of the retort through a suction manifold and discharged through a spreader which extends the length of the top of the retort. The holes in the water spreader must be uniformly distributed. The suction outlets must be protected with screens to keep debris from entering the recirculation system. The pump must be equipped with a pilot light or a similar device to warn the operator when it is not running and with a bleeder to remove air when starting operations. Alternatively, a flow-meter alarm system can be used to ensure proper water circulation. The adequacy of water circulation for maintaining uniform heat distribution within the retort must be documented by heat distribution data or other documentation from a processing authority, and such data must be maintained on file by the establishment and made available to Program employees for review. Alternative methods for recirculation of water in the retort may be used provided there is documentation in the form of heat distribution data or other documentation from a processing authority maintained on file by the establishment and made available to Program employees for review.
33. (vii) Cooling water entry. In retorts for processing product packed in glass jars, the incoming cooling water should not directly strike the jars, in order to minimize glass breakage by thermal shock.
34. (d) Pressure processing with steam/air mixtures in batch retorts—(1) Basic requirements. The basic requirements for indicating temperature devices and temperature/time recording devices are described in paragraphs (a)(1) and (2) of this section. Additionally, bulb sheaths or probes for indicating temperature devices and temperature/time recording devices or controller probes must be inserted directly into the retort shell in such a position that steam does not strike them directly.
35. (2) Recording pressure controller. A recording pressure controller must be used to control the air inlet and the steam/air mixture outlet.
36. (3) Circulation of steam/air mixtures. A means must be provided for the circulation of the steam/air mixture to prevent formation of low-temperature pockets. The efficiency of the circulation system must be documented by heat distribution data or other documentation from a processing authority, and such data must be maintained on file by the establishment and made available to Program employees for review. The circulation system must be checked to ensure its proper functioning and must be equipped with a pilot light or a similar device to warn the operator when it is not functioning. Because of the variety of existing designs, reference must be made to the equipment manufacturer for details of installation, operation, and control.
37. (e) Atmospheric cookers—(1) Temperature/time recording device. Each atmospheric cooker (e.g., hot water bath) must be equipped with at least one temperature/time recording device in accordance with the basic requirements described in paragraph (a)(2) of this section.
38. (2) Heat distribution. Each atmospheric cooker must be equipped and operated to ensure uniform heat distribution throughout the processing system during the thermal process. Heat distribution data or other documentation from the manufacturer or a processing authority demonstrating uniform heat distribution within the cooker must be kept on file by the establishment and made available to Program employees for review.
39. (f) Other systems. All other systems not specifically delineated in this section and used for the thermal processing of canned product must be adequate to produce shelf-stable products consistently and uniformly.

40. (g) Equipment maintenance.

    1. (1) Upon installation, all instrumentation and controls must be checked by the establishment for proper functioning and accuracy and, thereafter, at any time their functioning or accuracy is suspect.
    2. (2) At least once a year each thermal processing system must be examined by an individual not directly involved in daily operations to ensure the proper functioning of the system as well as all auxiliary equipment and instrumentation. In addition, each thermal processing system should be examined before the resumption of operation following an extended shutdown.
    3. (3) Air and water valves that are intended to be closed during thermal processing must be checked by the establishment for leaks. Defective valves must be repaired or replaced as needed.
    4. (4) Vent and bleeder mufflers must be checked and maintained or replaced by the establishment to prevent any reduction in bleeder efficiency.
    5. (5) When water spreaders are used for venting, a maintenance schedule must be developed and implemented to assure that the holes are maintained at their original size.
    6. (6) Records must be kept on all maintenance items that could affect the adequacy of the thermal process. Records must include the date and type of maintenance performed and the person conducting the maintenance.

41. (h) Container cooling and cooling water.

    1. (1) Potable water must be used for cooling except as provided for in paragraphs (h)(2) and (3) of this section.
    2. (2) Cooling canal water must be chlorinated or treated with a chemical having a bactericidal effect equivalent to chlorination. There must be a measurable residual of the sanitizer in the water at the discharge point of the canal. Cooling canals must be cleaned and replenished with potable water to prevent the buildup of organic matter and other materials.
    3. (3) Container cooling waters that are recycled or reused must be handled in systems that are so designed, operated, and maintained so there is no buildup of microorganisms, organic matter, and other materials in the systems and in the waters. System equipment, such as pipelines, holding tanks and cooling towers, must be constructed and installed so that they can be cleaned and inspected. In addition, the establishment must maintain, and make available to Program employees for review, information on at least the following:
42. (i) System design and construction;
43. (ii) System operation including the rates of renewal with fresh, potable water and the means for treating the water so that there is a measurable residual of an acceptable sanitizer, per paragraph (h)(2) of this section, in the water at the point where the water exits the container cooling vessel;
44. (iii) System maintenance including procedures for the periodic cleaning and sanitizing of the entire system; and
45. (iv) Water quality standards, such as microbiological, chemical and physical, monitoring procedures including the frequency and site(s) of sampling, and the corrective actions taken when water quality standards are not met.
46. (i) Post-process handling of containers. Containers must be handled in a manner that will prevent damage to the hermetic seal area. All worn and frayed belting, can retarders, cushions, and the like must be replaced with nonporous materials. To minimize container abrasions, particularly in the seal area, containers should not remain stationary on moving conveyors. All post-process container handling equipment should be kept clean so there is no buildup of microorganisms on surfaces in contact with the containers.