Fume_Extractor_CFM_requirements.pdf

NAVAIR Ol-lA-34 T.O. 00-25-252 T.C. 9-238

Table 2-1. Lens Shades For Welding And Cutting

Electrode Metal Lens Method Diameter, Inch Thickness, Inch Number

Welding SMAW 1/16 to 5/32 ---- 10

3/16 to 1/4 ---- 12 5/16 to 3/8 ---- 14

GMAW 1/16 to 5/32 Ferrous 10/11 ---- Nonferrous 11

GTAW ---- Ferrous 10/11 ---- Nonferrous 10/11

Atomic Hydrogen ---- ---- 10 to 14 Carbon-arc ---- ---- 10/12 Air Arc Cutting 5/32 to 1/4 carbon ---- 10 to 14 Gas Torch ---- to 1/8 4 or 5

---- 1/8 to 1/2 5 or 6 ---- over 1/2 6 or 8

Brazing Torch ---- ---- 3 or 4 Cutting Torch ---- to 1 3 or 4**

---- 1 to 6 4 or 5 ---- over 6 5 or 6

Soldering Torch ---- ---- 2

*Too dark or too light lens cause eyestrain.

**Goggles need sideshields.

Table 2-2. Required Exhaust Ventilation

Minimum Air Flow, Duct Diameter Welding Zone Cubic Feet/Minute* Inches** 4 to 6 inches tram arc or torch 150 3 6 to 8 inches from arc or torch 275 3-1/2 8 to 10 inches from arc or torch 425 4-1/2 10 to 12 inches from arc or torch 600 6-1/2

* w nen brazing with cadmium bearing materials or when cutting on such materials increased rates of ventilation may be required.

** Nearest half-inch duct diameter based on 4,000 feet per minute velocity in pipe.

2.2.10.5 VENTILATION FOR GENERAL WELDING

AND CUTTING. Mechanical ventilation shall be provided when welding or brazing is performed:

a. In a space of less than 10,000 cubic feet per welder.

b. In a room having a ceiling height of less than 16 ft.

c. In confined spaces or where the welding space con tains partitions, balconies, or other structural barriers to the extent that they significantly obstruct cross ventilation.

2-8

2.2.10.6 MINIMUM RATE. Such ventilation shall be at

the minimum rate of 2,000 cubic feet per minute per welder, except where local exhaust hoods and boots as in paragraph 2.3, or airline respirators approved by the US Bureau of Mines, National Institute of Occupational Safety and Health or other governmental approved testing agency may be used.

When welding with rods larger than 3/16-inches in diame ter, the ventilation shall be higher as shown in the following table:

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