Proper Venting and Drainage Hole Placement and Dimensions for Handrails
Paragraph numbers correspond with number references on the following illustration:
- External vent holes must be as close to the weld as possible and must be 25% the size of the internal diameter of the pipe, but not less than 3/8” (10 mm) in diameter.
- Internal holes should be the full internal diameter of the pipe for the best quality, lowest cost galvanizing.
- Vent holes in end sections or in similar sections must be 1/2” (13 mm) in diameter.
- Ends should be left completely open. Any device used for field-erection that prevents full openings on ends of horizontal rails and vertical legs should be galvanized separately and attached after galvanizing.