Tenn. Comp. R. & Regs. 1200-03-18-.31 - SOLVENT METAL CLEANING

(1) This rule applies to all solvent metal cleaning sources with the following exemptions:

(a) Any open top vapor degreasing operation with an open area smaller than 1 square 22 meter (m ) (10.8 square feet [ft ]) is exempt from Subparts (3)(b)3(ii) and (iv) of this rule;

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(b) Any conveyorized degreaser with an air/solvent interface smaller than 2.0 m (21.5 ft ) is exempt from Part (3)(c)2 of this rule; and

(c) Sources within a facility:

1. In Hamilton or Shelby County whose potential VOC emissions from all solvent metal cleaning within the facility are less than 25 tons of volatile organic compounds (VOC's) per year; or

2. In any county other than Davidson, Hamilton, Rutherford, Shelby, Sumner, Williamson, or Wilson County whose potential VOC emissions from all solvent metal cleaning within the facility are less than 100 tons of volatile organic compounds (VOC's) per year.

(2) For the purpose of this rule, the following definitions apply:

(a) "Air/solvent interface" means the surface area defined by points of contact between the solvent liquid or vapor in the cleaner/degreaser and the surrounding air.

(b) "Cold cleaning" means the batch process of cleaning and removing soils from a metal surface by spraying, brushing, flushing, or immersion while maintaining the solvent below its boiling point. Wipe cleaning is not included in this definition.

(c) "Conveyorized degreasing" means the process of cleaning and removing soils from a continuous stream of metal parts using either cold or vaporized solvents.

(d) "Freeboard height" means, for a cold cleaner, the distance from the liquid solvent level in the degreaser tank to the lip of the tank. For an open-top vapor degreaser, it is the distance from the vapor level in the tank during idling to the lip of the tank. For a vapor-conveyorized degreaser, it is the distance from the vapor level to the bottom of the entrance or exit opening, whichever is lower. For a cold-conveyorized degreaser, it is the distance from the liquid solvent level to the bottom of the entrance or exit opening, whichever is lower.

(e) "Freeboard ratio" means the freeboard height divided by the smaller interior dimension (length, width, or diameter) of the degreaser tank.

(f) "Open-top vapor degreasing" means the process using condensation of hot solvent vapor to clean and remove soils from a batch of metal parts.

(g) "Refrigerated chiller" means a device mounted above both the water jacket and the primary condenser coils which carries a refrigerant that provides a chilled air blanket above the solvent vapor, thereby reducing emissions from the degreaser bath.

(h) "Solvent metal cleaning" means the process of cleaning soils from metal surfaces by cold cleaning, open-top vapor degreasing, or conveyorized degreasing.

(3) Standards as follow apply:

(a) The owner or operator of a cold cleaning facility shall:

1. Equip the cleaner with a cover that is easily operated with one hand, if:

(i) The solvent true vapor pressure is greater than 2 kiloPascals (kPa) (15 millimeters of Mercury [mm Hg] or 0.3 pounds per square inch [psi]) measured at 38C (100°F) by ASTM D323-89;

(ii) The solvent is agitated; or

(iii) The solvent is heated;

2. Equip the cleaner with an internal drainage facility so that parts are enclosed under the cover while draining if the solvent true vapor pressure is greater than 4.3 kPa (32 mm Hg or 0.6 psi) measured at 38°C (100°F) by ASTM D323-89, except that the drainage facility may be external for applications where an internal type cannot fit into the cleaning system;

3. Implement one of the following control measures if the solvent true vapor pressure is greater than 4.3 kPa (32 mm of mercury or 0.6 psi) measured at 38°C (100°F) by ASTM D323-89, or if the solvent is heated above 50°C (120°F):

(i) Freeboard that gives a freeboard ratio greater than or equal to 0.7; or

(ii) Water cover at least 2.54 centimeters (1 inch) in depth (solvent shall be insoluble in and heavier than water); or

(iii) Another system of equivalent control, such as a refrigerated chiller or a arbon adsorber, approved as a revision to the State Implementation Plan;

4. Provide a permanent, legible, conspicuous label, summarizing the operating requirements;

5. Store waste solvent in covered containers;

6. Close the cover whenever parts are not being handled in the cleaner;

7. Drain the cleaned parts until dripping ceases;

8. If used, supply a solvent spray that is a solid fluid stream (not a fine, atomized, or shower-type spray) at a pressure that does not exceed 10 pounds per square inch gauge (psig); and

9. Degrease only materials that are neither porous nor absorbent.

(b) The owner or operator of an open top vapor degreaser shall:

1. Equip the vapor degreaser with a cover that can be opened and closed easily without disturbing the vapor zone;

2. Provide the following safety switches:

(i) A vapor level thermostat that shuts off the sump heat if the condenser coolant is either not circulating or too warm; and

(ii) A spray safety switch that shuts off the spray pump if the vapor level drops more than 10 centimeters (cm) (4 inches [in]);

3. Implement one of the following control measures:

(i) Freeboard ratio greater than or equal to 0.75 and, if the degreaser opening 22 is greater than 1 m (10.8 ft ), a powered cover;

(ii) Refrigerated chiller;

(iii) Enclosed design (cover or door opens only when the dry part is actually entering or exiting the degreaser);

(iv) Carbon adsorption system, with ventilation greater than or equal to 15 32 cubic meters per minute per square meter (m /min/m ) (50 cubic feet per 32 minute per square foot [ft /min/ft ]) of air/solvent interface (when cover is open), and exhausting less than 25 parts per million (ppm) of solvent averaged over one complete adsorption cycle, or 24 hours, whichever is less; or

(v) A control system, demonstrated to have a capture efficiency equivalent to or greater than any of the above and approved as a revision to the State Implementation Plan;

4. Keep the cover closed at all times except when processing work loads through the degreaser;

5. Minimize solvent carryout by:

(i) Racking parts so that solvent will drain freely and not be trapped;

(ii) Moving parts in and out of the degreaser at less than 3.3 meters per minute (m/min) (11 feet per minute [ft/min]);

(iii) Holding the parts in the vapor zone at least 30 seconds or until condensation ceases, whichever is longer;

(iv) Tipping out any pools of solvent on the cleaned parts before removal from the vapor zone; and

(v) Allowing parts to dry within the degreaser for at least 15 seconds or until visually dry, whichever is longer.

6. Degrease only materials that are neither porous nor absorbent;

7. Occupy no more than one-half of the degreaser's open top area with a workload;

8. Always spray within the vapor level;

9. Repair solvent leaks immediately, or shut down the degreaser;

10. Store waste solvent only in covered containers;

11. Operate the cleaner such that water cannot be visually detected in solvent exiting the water separator;

12. Use no ventilation fans near the degreaser opening;

13. When the cover is open, not expose the open top vapor degreaser to drafts greater than 40 m/min (131 ft/min), as measured between 1 and 2 m upwind and at the time elevation as the tank lip;

14. If a lip exhaust is used on the open top vapor degreaser, not use a ventilation rate that exceeds 20 m³ /min/m² (65 ft³ /min/ft² ) of degreaser open area, unless a higher rate is necessary to meet OSHA requirements; and

15. Provide a permanent, conspicuous label, summarizing the operating procedures of Parts 4 through 14 of this subparagraph.

(c) The owner or operator of a conveyorized degreaser shall:

1. Use no workplace fans near the degreaser opening, and ensure that exhaust 3 232 ventilation does not exceed 20 m /min/m (65 ft /min/ft ) of degreaser opening , unless a higher rate is necessary to meet OSHA requirements;

2. Install one of the following control devices:

(i) Refrigerated chiller;

(ii) Carbon adsorption system, with ventilation greater than or equal to 15 m³ /min/m² (50 ft³ /min/ft² ) of air/solvent interface (when downtime covers are open), and exhausting less than 25 ppm of solvent by volume averaged over one complete adsorption cycle, or 24 hours, whichever is less; or

(iii) A system demonstrated to have a capture efficiency equivalent to or greater than the device listed in Subpart 2(i) or (ii) of this subparagraph and approved as a revision to the State Implementation Plan;

3. Equip the cleaner with equipment, such as a drying tunnel or rotating (tumbling) basket, sufficient to prevent cleaned parts from carrying out solvent liquid or vapor;

4. Provide the following safety switches:

(i) A condenser flow switch and thermostat that shut off the sump heat if the condenser coolant is either not circulating or too warm;

(ii) A spray safety switch which shuts off the spray pump or the conveyor if the vapor level drops more than 10 cm (4 in); and

(iii) A vapor level control thermostat that shuts off the pump heat when the vapor level rises too high;

5. Minimize openings during operation so that entrances and exits will silhouette workloads with an average clearance between the parts and the edge of the degreaser opening of less than 10 cm (4 in) or less than 10 percent of the width of the opening;

6. Provide downtime covers for closing off the entrance and exit during shutdown hours;

7. Minimize carryout emissions by:

(i) Racking parts so that solvent will drain freely from parts and not be trapped; and

(ii) Maintaining the vertical conveyor speed at less than 3.3 m/min (11 ft/min);

8. Store waste solvent only in covered containers;

9. Repair solvent leaks immediately, or shut down the degreaser;

10. Operate the cleaner such that water cannot be visually detected in solvent exiting the water separator;

11. Place downtime covers over entrances and exits of the conveyorized degreaser at all times, except during maintenance activities on the degreaser, when the conveyors and exhausts are not being operated; and

12. Degrease only materials that are neither porous nor absorbent.

(4) Compliance with Parts (3)(a)1 through 3, Subpart (3)(b)3(iv), Parts (3)(b)7 through 14, Part (3)(c)1, and Subpart (3)(c)2(ii) of this rule shall be determined by applying the following test methods, as appropriate:

(a) Reference Methods 1-4 for determining flow rates.

(b) Reference Method 18 for determining gaseous organic compound emissions by gas chromatography.

(c) Reference Method 25 for determining total gaseous non-methane organic emissions as carbon.

(d) Reference Method 25A or 25B for determining total gaseous organic concentrations using flame ionization or non-dispersive infrared analysis.

(e) ASTM D323-89 for measuring solvent true vapor pressure.

(5) Each owner or operator of a solvent metal cleaning source subject to this rule shall maintain the following records for at least 3 years and shall make these records available to the Technical Secretary upon request:

(a) A record of central equipment maintenance, such as replacement of the carbon in a carbon adsorption unit.

(b) The results of all tests conducted in accordance with the requirements in Paragraph (4) of this rule.

(6) The owner or operator of any facility containing sources subject to this rule shall:

(a) Comply with the initial compliance certification requirements of Paragraph .04(1) of this chapter;

(b) Comply with the requirements of Paragraph .04(2) of this chapter regarding reports of excess emissions; and

(c) Comply with the requirements of Paragraph .04(3) of this chapter for excess emissions related to any control devices used to comply with Subparts (3)(a)3(iii), (3)(b)3(iv) or (v), and (3)(c)1(ii) or (iii) of this rule.

Notes

Tenn. Comp. R. & Regs. 1200-03-18-.31

Original rule filed March 8, 1993; effective April 22, 1993.

Authority: T.C.A. §§ 4-5-202 and 68-201-105.