250 R.I. Code R. 250-RICR-120-05-36.13

Current through December 26, 2024

Section 250-RICR-120-05-36.13 - Compliance Specifications and Monitoring Requirements for Solvent Cleaning Machines

A. The owner or operator of a solvent cleaning machine shall monitor the following parameters and record the results:

1. The cover of each batch vapor or in-line cleaning machine shall be visually inspected monthly to confirm that it is opening and closing properly, that it completely covers the cleaning machine's openings when closed, and that it is free of cracks, holes, and other defects.

2. The speed of automated parts handling systems shall be monitored according to the following specifications:

a. Determine the speed by measuring the time it takes for the conveyor to travel a measured distance. The speed is the distance in inches divided by the time in seconds, or the distance in feet divided by the time in minutes; and

b. Monitoring shall be performed on a monthly basis. If no exceedances of the speed requirements specified in §§ 36.10(C) and 36.11(C) of this Part occur in a year, then future hoist speed monitoring may be conducted on a quarterly basis; and

c. If a speed greater than that specified in §§ 36.10(C) and 36.11(C) of this Part is measured, the automated parts handling system must be adjusted so that this specification is met; and

d. If a speed greater than that specified in §§ 36.10(C) and 36.11(C) of this Part is measured while monitoring is being conducted on a quarterly basis, then monthly monitoring must be resumed until another year passes without any exceedances.

3. If a refrigerated freeboard chiller is used, the temperature at the coldest point of the centroid of the chilled air blanket shall be no greater than thirty percent (30%) of the solvent's boiling point, measured in degrees Fahrenheit (° F), and shall be monitored weekly according to the following specifications:

a. The temperature shall be monitored while the batch vapor or in-line cleaning machine is operating in the idling mode; and

b. A thermometer or thermocouple shall be used to measure the temperature at the centroid of the air blanket; and

c. If the temperature at the coldest point of the centroid of the air blanket exceeds thirty percent (30%) of the solvent's boiling point, measured in degrees Fahrenheit (° F), the chiller shall be adjusted so that this specification is met.

4. If a superheated vapor system is used, the temperature of the solvent vapor at the centroid of the superheated vapor zone shall be maintained at least ten degrees Fahrenheit (10° F) above the solvent's boiling point and shall be monitored weekly according to the following specifications:

a. The temperature shall be monitored while the batch vapor or in-line cleaning machine is operating in the idling mode; and

b. A thermometer or thermocouple shall be used to measure the temperature at the centroid of the superheated solvent vapor zone; and

c. If the temperature at the centroid of the air blanket is less than ten degrees Fahrenheit (10° F) above the solvent's boiling point, the system shall be adjusted so that this specification is met.

5. If a carbon adsorber is used, the concentration of solvent in the exhaust shall not exceed twenty-five (25) ppm. Compliance with this requirement shall be determined using the following methods:

a. Within sixty (60) days of initial startup of the carbon adsorber, the solvent concentration in the carbon adsorber exhaust shall be tested using 40 C.F.R Part 60, app A-7, Method 25, incorporated in § 36.4 of this Part. Each test shall consist of three (3) separate one (1) hour samples, and the arithmetic mean shall be used to determine initial compliance. The results shall be reported to the Office of Air Resources within sixty (60) days of the test.

b. Continuing compliance shall be determined weekly using the following procedure:

(1) The concentration of solvent in the exhaust shall be measured while the cleaning machine is in the working mode and is exhausting to the carbon adsorber; and

(2) An easily accessible sampling port shall be provided that is located on the exhaust outlet at least eight (8) stack or duct diameters downstream and two (2) stack or duct diameters upstream of any flow disturbance such as a bend, expansion, contraction, or outlet. The sampling port must not be downstream of any other inlet; and

(3) Solvent concentration shall be measured at the sampling port using a colorimetric detector tube capable of detecting twenty-five (25) ppm with an accuracy of ± twenty-five percent (25%) or better; and

(4) Colorimetric detector tubes must be used according to the manufacturer's instructions; and

(5) If the carbon adsorber's exhaust exceeds twenty-five (25) ppm then the desorption cycle shall be adjusted or the carbon canister replaced in order to bring the exhaust concentration below twenty-five (25) ppm; and

(6) If desorption of the carbon adsorber is required, the carbon adsorber shall not be bypassed during the desorption cycle.

6. If dwell or a superheated vapor system is used, the actual dwell time shall equal or exceed the minimum dwell time. Minimum and actual dwell time shall be determined using the following procedures:

a. For units without a superheated vapor system, the minimum dwell time shall be determined for each part type or parts basket or for the most complex part type or parts basket using the following procedure:

(1) Determine the amount of time necessary for the part or parts basket to cease dripping once placed in the vapor zone. The part or parts basket used for this determination must be at room temperature when placed in the vapor zone; and

(2) The minimum dwell time required for parts to remain in the freeboard zone above the vapor zone is calculated as thirty-five percent (35%) of the time determined in § 36.13(A)(6)(a) ((1)) of this Part.

b. The minimum dwell time for a cleaning machine equipped with a superheated vapor system shall be determined according to the specifications of the manufacturer of the control equipment; and

c. On a monthly basis, the actual dwell time that parts are held in the freeboard zone above the vapor zone shall be measured; and

d. If the actual dwell time is less than the minimum dwell time determined using the applicable procedure in §§ 36.13(A)(6)(a) or (b) of this Part for a particular part or parts basket, the automatic parts handling system must be adjusted so that this specification is met.

7. Safety switches must be tested semiannually.

8. Alternative monitoring procedures may be used if approved by the Director and the EPA.

250 R.I. Code R. 250-RICR-120-05-36.13

Adopted effective 1/13/2019
Amended effective 6/13/2022