Section 20-766. SOLVENT CLEANING – IN-LINE VAPOR CLEANING

 

766.1This section applies to in-line vapor cleaning machines.

 

766.2In-line 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;

 

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

 

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

 

(d)A vapor up control switch;

 

(e)An automated parts handling system that moves the parts or parts baskets at a speed of eleven feet (11 ft.) or 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 per minute (3 ft./min.);

 

(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 permanent, conspicuous label summarizing the operating requirements in § 766.4;

 

(i)A primary condenser; and

 

(j)Each 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).

 

766.3 The operator of an in-line vapor cleaning machine shall use one (1) of the following devices or strategies:

 

(a)A 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 a freeboard ratio of one (1.0);

 

(c)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. Dwell shall be not less than thirty-five percent (35%) of the dwell time determined for the part or parts; or

 

(d)Dwell 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. Dwell shall be not less than thirty-five percent (35%) of the dwell time determined for the part or parts.

 

766.4 In-line 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)Parts shall be oriented so that the solvent drains freely from the parts;

 

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

 

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

 

(c) Parts baskets or parts shall not be removed from the in-line 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 in-line 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)Sponges, fabric, wood, leather, paper products, and other absorbent materials shall not be cleaned in the in-line vapor cleaning machine;

 

(f)Spills during solvent transfer and use of the in-line vapor cleaning machine shall be cleaned up immediately, and the wipe rags or other absorbent materials shall be immediately stored in covered containers for disposal or recycling;

 

(g)Workplace fans shall not be used near the degreaser opening unless a higher rate is necessary to meet federal Occupational Safety & Health Administration (OSHA) requirements;

 

(h) During startup of the in-line vapor cleaning machine the primary condenser shall be turned on before the sump heater;

 

(i)During shutdown of the in-line 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;

 

(j)Spraying operations shall be done in the vapor zone or within a section of the machine that is not exposed to the ambient air;

 

(k)When solvent is added to or drained from the in-line 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; and

 

(l)Openings shall be minimized during operations so that entrances and exits silhouette workloads with an average clearance between the parts and the edge of the degreaser opening of less than ten centimeters (10 cm.) or four inches (4 in.) or less than ten percent (10%) of the width of the opening.

 

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.

source

Notice of Final Rulemaking published at 58 DCR 11286, 11379 (December 30, 2011).