Attachment 2 - Vendor Questions and Corresponding Government Answers.pdf

Could you please provide clarification on the following questions?

1. Required temperature uniformity: What temperature uniformity is the oven required to achieve within its usable work zone—for example, ±5°F, ±10°F, ±15°F, ±25°F, or another tolerance?

A. We are allowed ±15°F.

2. AMS2750: Is the oven required to comply with AMS2750 or another pyrometry/process specification? If AMS2750 applies, what furnace class and instrumentation type are required, and what revision is applicable?

A. The Government believes it is.

3. TUS/SAT records: Please provide the most recent successful and unsuccessful Temperature Uniformity Survey (TUS) and System Accuracy Test (SAT) reports, if applicable. Has failure of a TUS or SAT contributed to the oven being taken out of service?

A. This is unknown and we do not have any documented failures of the test and no surveys.

4. NFPA 86 classification: Does McConnell AFB currently consider and operate the oven as an NFPA 86 Class A oven in accordance with the manufacturer's safety-design nameplate? Has the process, solvent loading, batch size, operating temperature, or intended use changed from the original design?

A. Yes, it follows the NFPA 86 class A.

5. Nature of the failure: What specifically is the oven presently not doing? Does it fail to start, purge, ignite, heat, maintain temperature, achieve uniformity, achieve/maintain vacuum, complete a cure cycle, or pass a required inspection/test? Are there any known alarms or intermittent faults?

A. This is unknown.

6. Last successful operation: When was the last time the oven successfully processed an acceptable production load, and why was it subsequently removed from service?

A. The last known run of the system was well over 3 years ago.

7. Door/latch condition: One of the supplied photographs appears to show that a portion of the door-closing/latching mechanism is missing. Is the oven door currently capable of being completely closed, latched, and sealed? Please provide detailed photographs of the complete door perimeter, seals/gaskets, hinges, and all latching components.

A. The door latch broke off and it won’t fully close.

8. Vacuum performance: What vacuum level is required at each process connection? Is there a specified allowable leakage/decay rate, and are all six vacuum connections required to operate simultaneously?

A. We need at a minimum, a vacuum pressure of 25, no allowable leakage or decay rate and it would be preferred to have all 6 work in tandem if possible.

9. Vacuum monitoring: The photographs appear to show six vacuum process connections and individual vacuum sensing devices/transducers. Are the individual vacuum levels monitored and/or recorded during a production cure? If so, where is that data recorded?

A. Unsure if there is a screen or program that records that data. To our knowledge, the vacuum has never been operated.

10. Data acquisition/BMS: The paper chart recorder visible in the photographs appears to have only one pen, presumably recording oven temperature. Are the vacuum readings and/or additional oven process variables recorded elsewhere, such as through the facility's Schneider Electric EcoStruxure Building Management System or another data-acquisition system?

A. To our knowledge, the oven’s heating operation was the only working portion of the process.

11. Powerex vacuum system: When was the Powerex vacuum pump/system last successfully operated, and when was it last serviced? Please provide any available service and maintenance history.

A. This is unknown.

12. Equipment maintenance records: Please provide available maintenance records, previous troubleshooting/service reports, calibration records, and repair history for both the Grieve oven and Powerex vacuum system.

A. We do not have any records of repairs or servicing for either system.

13. Burner and gas train: Please provide detailed photographs showing the burner and complete gas train, including readable manufacturer/model information for the burner, flame safeguard/burner management equipment, combustion blower, regulators, safety shutoff valves, gas pressure switches, and modulating actuators.

A. Pictures are attached.

14. Heating configuration: The manufacturer's safety-design plate states that products of combustion enter the oven, which appears consistent with a direct-fired heating arrangement.

Please confirm whether the burner fires directly into the recirculating oven atmosphere or through a heat exchanger.

A. Can not confirm.

15. Current process materials: The original Class A safety-design plate lists MEK, acetone, alcohol, and methyl propyl ketone, with up to 0.20 gallons of solvent/volatiles entering the oven per batch. Does the current process actually introduce these or other flammable volatiles? Are the composite parts processed exposed/unbagged, vacuum-bagged, or both?

1. Yes, and both.

16. Oven interior/air distribution: None of the supplied photographs show the interior of the oven.

Please provide detailed photographs of the entire work zone, supply and return openings, plenums, baffles, adjustable dampers, and other components of the internal air-distribution system.

A. Pictures are attached.

17. Previous airflow adjustments: Have the oven's internal dampers or air-distribution components previously been adjusted in an attempt to correct a temperature-uniformity problem? If so, are the original settings or balancing information available?

A. This is unknown.

18. Combustion/emissions records: Is a recent burner combustion-analysis or emissions report available? Please provide the most recent report and any burner setup/commissioning documentation.

A. This is not available.

19. Drawings/manuals: Please provide available electrical drawings, combustion/gas-train drawings, vacuum-system drawings, mechanical/airflow drawings, sequence of operation, Grieve manuals, and controls documentation.

A. All available documents are attached.

20. Modification history: Has the oven's original control, combustion, ventilation, vacuum, or air-distribution system been modified? The photographs appear to show newer Watlow controls. If the controls have been upgraded, please provide documentation of the modification, if available.

A. Not that we are aware of.