40 CFR 204.55-3: -3 Configuration identification.

(a) A separate compressor configuration shall be determined by each combination of the following parameters:

(1) The compressor type (screw, sliding vane, etc.).

(2) Number of compressor stages.

(3) Maximum pressure (psi).

(4) Air intake system of compressor:

(i) Number of filters;

(ii) Type of filters.

(5) The engine system:

(i) Number of cylinders and configuration (L-6, V-8, V-12);

(ii) Displacement;

(iii) Horsepower;

(iv) Full load rpm.

(6) Type cooling system, e.g., air cooled, water cooled.

(7) Fan:

(i) Diameter;

(ii) Maximum fan rpm.

(8) The compressor enclosure:

(i) Height, length, and width;

(ii) Acoustic material manufacturer, type, part number.

(9) The induction system (engine):

(i) Natural;

(ii) Turbocharged.

(10) The muffler:

(i) Manufacturer;

(ii) Manufacturer part number;

(iii) Quantity of mufflers used;

(11) Category parameters listed at § 204.55-2.