Ala. Admin. Code r. 335-3-6-.12

Current through Register Vol. 42, No. 12, September 30, 2024

Section 335-3-6-.12 - Solvent Metal Cleaning

(1) For the purpose of this Rule, the following definitions apply:

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

(b) "Conveyorized Degreasing" shall mean the continuous process of cleaning and removing soils from metal surfaces by operating with either cold or vaporized solvents.

(c) "Freeboard Height" shall mean for a cold cleaner, the distance from the liquid solvent level in the degreaser tank to the lip of the tank. For vapor degreasers, it is the distance from the solvent level in the tank to the lip of the tank.

(d) "Freeboard Ratio" shall mean the freeboard height divided by the width of the degreaser.

(e) "Open Top Vapor Degreasing" shall mean the batch process of cleaning and removing soils from metal surfaces by condensing hot solvent vapor on the colder metal parts.

(f) "Solvent Metal Cleaning" shall mean the process of cleaning soils from metal surfaces by cold cleaning or open top vapor degreasing or conveyorized degreasing.

(2) This Rule will apply to cold cleaning, open top vapor degreasing and conveyorized degreasing operations.

(3) The provisions of this Rule shall apply with the following exceptions:

(a) Open top vapor degreasers with an open area smaller than one square meter (10.8 square feet) shall be exempt from this Rule.

(b) Conveyorized degreasers with an air/vapor interface smaller than 2.0 square meters (21.6 square feet) shall be exempt from this Rule.

(4) Except as provided under paragraph (3) above, the owner or operator of a cold cleaning device shall:

(a) equip the cleaner with a cover and the cover shall be so designed that it can be easily operated with one hand; if,

1. the solvent volatility is greater than 2 kPa (15 millimeters of mercury or 0.3 pounds per square inch) measured at 38° C (100° F); or

2. the solvent is agitated; or

3. the solvent is heated; and

(b) equip the cleaner with a device for draining cleaned parts; and if the solvent volatility is greater than 4.3 kPa (32 millimeters of mercury or 0.6 pounds per square inch) measured at 38° C (100° F), equip the construct drainage device internally so that the parts are enclosed under the cover while draining, except that the drainage device may be external for applications where an internal type cannot fit into the cleaning systems; and

(c) if the solvent volatility is greater than 4.3 kPa (32 millimeters of mercury or 0.6 pounds per square inch) measured at 38° C (100° F) or if the solvent is heated above 50° C (120° F), install one of the following devices:

1. freeboard that gives a freeboard ratio greater than or equal to 0.7; or

2. water cover (solvent must be insoluble in and heavier than water); or

3. other systems of equivalent control, such as refrigerated chiller or carbon absorption, approved by the Director; and

(d) provide a permanent, conspicuous label, summarizing the operating requirements; and

(e) close the cover whenever parts are not being handled in the cleaner; and

(f) drain the cleaned parts for at least 15 seconds or until dripping ceases; and

(g) if used, supply a solvent spray that is a solid fluid stream (not a fine, atomized, or shower type spray) at a pressure which does not cause excessive splashing; and

(h) store waste solvent only in covered containers and not dispose of waste solvent or transfer it to another party, such that greater than twenty percent (20%) of the waste solvent (by weight) can evaporate into the atmosphere.

(5) Except as provided under paragraph (3) above, the owner or operator of an open top vapor degreaser shall;

(a) equip the vapor degreaser with a cover that can be opened and closed easily without disturbing the vapor zone; and

(b) provide the following safety switches:

1. a condenser flow switch and thermostat which shuts off the heat if the condenser coolant is either not circulating or too warm; and

2. Reserved.

3. a vapor level control thermostat which shuts off the heat when the level rises too high.

(c) install one of the following control devices:

1. a freeboard ratio of greater than or equal to 0.75 and a powered or mechanically assisted cover if the degreaser opening is greater than 1 square meter (10.8 square feet); or

2. refrigerated chiller; or

3. enclosed design (cover or door opens only when the dry part is actually entering or exiting the degreaser); or

4. carbon adsorption system with ventilation greater than or equal to 15 cubic meters per minute per square meter (50 cubic feet per minute per square foot) of air/vapor area (when cover is open) and exhausting less than 25 parts per million of solvent averaged over one complete adsorption cycle; or

5. a control system, demonstrated to have control efficiency equivalent to or greater than any of the above and approved by the Director; and

(d) keep the cover closed at all times except when processing work loads through the degreaser; and

(e) minimize solvent carryout by:

1. racking parts to allow complete drainage; and

2. moving parts in and out of the degreaser at less than 3.3 meters per minute (11 feet per minute); and

3. holding the parts in the vapor zone at least 30 seconds or until condensation ceases; and

4. tipping out any pools of solvent on the cleansed parts before removal from the vapor zone; and

5. allowing parts to dry within the degreaser for at least 15 seconds or until visually dry; and

(f) not degrease porous or absorbent materials, such as cloth, leather, wood or rope; and

(g) not occupy more than half of the degreaser's open top area with a workload; and

(h) Reserved.

(i) always spray below the vapor level; and

(j) repair solvent leaks immediately, or shutdown the degreaser; and

(k) store waste solvent only in covered containers and not dispose of waste solvent or transfer it to another party, such that greater than twenty percent (20%) of the waste solvent (by weight) can evaporate into the atmosphere; and

(l) not operate the cleaner so as to allow water to be visually detectable in solvent existing in the water separator; and

(m) not use ventilation fans near the degreaser opening nor provide exhaust ventilation exceeding 20 cubic meters per minute per square meter (65 cubic feet per minute per square foot) of degreaser open area, unless necessary to meet OSHA requirements.

(6) Except as provided under paragraph (3) above, the owner or operator of a conveyorized degreaser shall:

(a) not use workplace fans near the degreaser opening nor provide exhaust ventilation exceeding 20 cubic meters per minute per square meter (65 cubic feet per minute per square foot) of degreaser opening, unless necessary to meet OSHA requirements; and

(b) install one of the following control devices:

1. refrigerated chiller; or

2. carbon adsorption system with ventilation greater than or equal to 15 cubic meters per minute per square meter (50 cubic feet per minute per square foot) or air/vapor area (when downtime covers are open), and exhausting less than 25 parts per million of solvent by volume averaged over a complete adsorption cycle; or

3. a system demonstrated to have a control efficiency equivalent to or greater than subparagraphs (b)l. or (b)2. of this paragraph and approved by the Director; and

(c) equip the cleaner with equipment, such as drying tunnel or rotating (tumbling) basket sufficient to prevent cleaned parts from carrying out solvent liquid or vapor; and

(d) provide the following safety switches:

1. a condenser flow switch and thermostat which shut off the heat if the condenser is either not circulating or too warm; and

2. a spray safety switch which shuts off the spray pump or the conveyor if the vapor level drops more than 10 centimeters (4 inches) below the bottom of the condenser; and

3. a vapor level control thermostat which shuts off the heat when the level rises too high; and

(e) 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 ten centimeters (4 inches) or less than ten percent (10%) of the width of the opening; and

(f) provide downtime covers for closing off the entrance and exit during the shutdown hours; and

(g) minimize carryout emissions by:

1. racking parts for best drainage; and

2. maintaining the vertical conveyor speed at less than 3.3 meters per minute (11 feet per minute); and

(h) store waste solvent only in covered containers; and

(i) repair solvent leaks immediately, or shut down the degreasers; and

(j) not operate the cleaner so as to allow water to be visually detectable in solvent exiting the water separator; and

(k) place downtime covers over entrances and exits of conveyorized degreasers immediately after the conveyors and exhaust are shut down and not remove them until just before start-up.

Author: Wm. Gerald Hardy

Ala. Admin. Code r. 335-3-6-.12

Effective Date: November 26, 1979. Amended: March 24, 1981. Amended: Filed October 17, 1996; effective November 21, 1996.

Statutory Authority:Code of Ala. 1975, §§ 22-28-14, 22-22A-5, 22-22A-6, 22-22A-8.