D.C. Mun. Regs. r. 20-765

Current through Register Vol. 71, No. 25, June 21, 2024

Rule 20-765 - SOLVENT CLEANING - BATCH VAPOR CLEANING

765.1 This section applies to batch vapor cleaning machines that process metal parts.

765.2 Batch vapor cleaning machines shall be equipped with:

(a) Either a fully enclosed design, or a working and downtime mode cover that completely covers the cleaning machine openings when in place, is free of cracks, holes, and other defects, and can be readily opened or closed without disturbing the vapor zone;

(1) If the solvent cleaning machine opening is greater than ten square feet (10 sq. ft.), the cover must be powered; and

(2) If a lip exhaust is used, the closed cover shall be below the level of the lip exhaust;

(b) Sides that result in a freeboard ratio greater than or equal to seventy-five one hundredths (0.75);

(c) A safety switch (thermostat and condenser flow switch) that shuts off the sump heat if the coolant is not circulating;

(d) A vapor up control switch that shuts off the spray pump if vapor is not present;

(e) An automated parts handling system that moves the parts or parts baskets at a speed of eleven feet (11 ft.) (three and four tenths meters (3.4 m.)) per minute or less when the parts are entering or exiting the vapor zone. If the parts basket or parts being cleaned occupy more than fifty percent (50%) of the solvent/air interface area, the speed of the parts basket or parts shall not exceed three feet (3 ft.) per minute;

(f) A device that shuts off the sump heat if the sump liquid solvent level drops to the sump heater coils;

(g) A vapor level control device that shuts off the sump heat if the vapor level in the vapor cleaning machine rises above the height of the primary condenser;

(h) A primary condenser;

(i) A vapor cleaning machine that uses a lip exhaust shall be designed and operated to route all collected solvent vapors through a properly operated and maintained carbon adsorber such that the concentration of organic solvent in the exhaust does not exceed one hundred parts per million (100 ppm); and

(j) A permanent, conspicuous label summarizing the operating requirements found in § 765.5.

765.3

In addition to the requirements in § 765.2, the operator of a batch vapor cleaning machine with a solvent/air interface area of thirteen square feet (13 sq. ft.) or less shall use one of the following devices or strategies:

(a) A working mode cover, freeboard ratio of one (1.0), and superheated vapor;

(b) A freeboard refrigeration device operated to ensure that the chilled air blanket temperature is no greater than thirty percent (30%) of the solvent's boiling point and superheated vapor;

(c) A working mode cover and a freeboard refrigeration device operated to ensure that the chilled air blanket temperature is no greater than thirty percent (30%) of the solvent's boiling point;

(d) Reduced room draft, freeboard ratio of one (1.0), and superheated vapor;

(e) A freeboard refrigeration device operated to ensure that the chilled air blanket temperature is no greater than thirty percent (30%) of the solvent's boiling point and reduced room draft;

(f) A freeboard refrigeration device operated to ensure that the chilled air blanket temperature is no greater than thirty percent (30%) of the solvent's boiling point and a freeboard ratio of one (1.0);

(g) A freeboard refrigeration device operated to ensure that the chilled air blanket temperature is no greater than thirty percent (30%) of the solvent's boiling point and dwell. Dwell shall be not less than thirty-five percent (35%) of the dwell time determined for the part or parts;

(h) Reduced room draft, dwell, and a freeboard ratio of one (1.0);

(i) A freeboard refrigeration device operated to ensure that the chilled air blanket temperature is no greater than thirty percent (30%) of the solvent's boiling point and a carbon adsorber which reduces solvent emissions in the exhaust to a level not to exceed one hundred parts per million (100 ppm) at any time; and

(j) A freeboard ratio of one (1.0), superheated vapor, and a carbon adsorber which reduces solvent emissions in the exhaust to a level not to exceed one hundred parts per million (100 ppm) at any time.

765.4

In addition to the requirements of § 765.2, the operator of a batch vapor cleaning machine with a solvent/air interface area of greater than thirteen square feet (13 sq. ft.) shall use one of the following devices or strategies:

(a) A freeboard refrigeration device operated to ensure that the chilled air blanket temperature is no greater than thirty percent (30%) of the solvent's boiling point, a freeboard ratio of one (1.0), and superheated vapor;

(b) Dwell and a freeboard refrigeration device operated to ensure that the chilled air blanket temperature is no greater than thirty percent (30%) of the solvent's boiling point, and reduced room draft. Dwell shall be not less than thirty-five percent (35%) of the dwell time determined for the part or parts;

(c) A working mode cover and a freeboard refrigeration device operated to ensure that the chilled air blanket temperature is no greater than thirty percent (30%) of the solvent's boiling point and superheated vapor;

(d) Reduced room draft, freeboard ratio of one (1.0), and superheated vapor;

(e) A freeboard refrigeration device operated to ensure that the chilled air blanket temperature is no greater than thirty percent (30%) of the solvent's boiling point, reduced room draft, and superheated vapor;

(f) A freeboard refrigeration device operated to ensure that the chilled air blanket temperature is no greater than thirty percent (30%) of the solvent's boiling point, reduced room draft, and a freeboard ratio of one (1.0); or

(g) A freeboard refrigeration device operated to ensure that the chilled air blanket temperature is no greater than thirty percent (30%) of the solvent's boiling point, superheated vapor, and a carbon adsorber, which reduces solvent emissions in the exhaust to a level not to exceed one hundred parts per million (100 ppm) at any time.

765.5

Batch vapor cleaning machines shall be operated in accordance with the following procedures:

(a) Waste solvent, still bottoms, and sump bottoms shall be collected and stored in closed containers. The closed containers may contain a device that allows pressure relief but does not allow liquid solvent to drain from the container;

(b) Cleaned parts shall be drained at least fifteen (15) seconds or until dripping ceases, whichever is longer:

(1) Parts having cavities or blind holes shall be tipped or rotated while the part is draining; and

(2) A superheated vapor system shall be an acceptable alternate technology;

(c) Parts baskets or parts shall not be removed from the batch vapor cleaning machine until dripping has ceased;

(d) Flushing or spraying of parts using a flexible hose or other flushing device shall be performed within the vapor zone of the batch vapor cleaning machine or within a section of the machine that is not exposed to the ambient air. The solvent spray shall be a solid fluid stream, not an atomized or shower spray;

(e) When the cover is open, the batch vapor cleaning machine shall not be exposed to drafts greater than forty meters (40 m.) per minute (one hundred thirty-two feet (132 ft.) per minute), as measured between one meter (1 m.) and two meters (2 m.) (three and three tenths feet (3.3 ft.) and six and six tenths feet (6.6 ft.) upwind and at the same elevation as the tank lip;

(f) Sponges, fabric, wood, leather, paper products, and other absorbent materials shall not be cleaned in the batch vapor cleaning machine;

(g) Spills during solvent transfer and use of the batch vapor cleaning machine shall be cleaned up immediately or the machine shall be shut down. Wipe rags or other absorbent materials shall be immediately stored in covered containers for disposal or recycling;

(h) Work area fans shall be located and positioned so that they do not blow across the opening of the batch vapor cleaning machine;

(i) During startup of the batch vapor cleaning machine the primary condenser shall be turned on before the sump heater;

(j) During shutdown of the batch vapor cleaning machine, the sump heater shall be turned off and the solvent vapor layer allowed to collapse before the primary condenser is turned off;

(k) When solvent is added to or drained from the batch vapor cleaning machine, the solvent shall be transferred using threaded or other leak proof couplings and the end of the pipe in the solvent sump shall be located beneath the liquid solvent surface;

(l) The working and downtime covers shall be closed at all times except during parts entry and exit from the machine, during maintenance of the machine when the solvent has been removed, and during addition of solvent to the machine; and

(m) If a lip exhaust is used on the open top vapor degreaser, the ventilation rate shall not exceed twenty meters cubed per minute per meters squared (20 m.³/min./m.²) or sixty-five feet cubed per minute per feet squared (65 ft.³/min./ft.²) of degreaser open area, unless a higher rate is necessary to meet federal Occupational Safety & Health Administration (OSHA) requirements.

D.C. Mun. Regs. r. 20-765

Notice of Final Rulemaking published at 58 DCR 11286, 11374 (December 30, 2011)

Authority: The Director of the District Department of the Environment (DDOE or Department), pursuant to the authority set forth in sections 5 and 6(b) of the District of Columbia Air Pollution Control Act of 1984, as amended, effective March 15, 1985 (D.C. Law 5-165 (DCAPC); D.C. Official Code §§ 8-101.05 and 8-101.06(b) (2008 Repl.)), section 107(4) of the District Department of the Environment Establishment Act of 2005, effective February 15, 2006 (D.C. Law 16-51; D.C. Official Code § 8-151.07(4) (2008 Repl.)), Mayor's Order 98-44, dated April 10, 1998, and Mayor's Order 2006-61, dated June 14, 2006.