Standard dimensions for shell manholes, shell nozzles, roof manholes, roof nozzles, drain pads, and flush-type cleanout fittings
◉ IS 803-1976 (REAFFIRMED 2006), §7, TABLES 8–16 · NOT A REGULATORY SUBMISSION TOOL
⚠ Indicative tool only. Source: IS 803-1976, Tables 8–16, read from the code's own text. These are the code's own standard/typical dimensions (its Fig. 11–18), not a substitute for the referenced figures showing how each dimension is measured, nor for §6.3.7 (fillet weld sizing for attachment Types B, C, D) which several tables refer to but don't repeat.
Identification
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1. Shell Manholes (Tables 8, 9 — Fig. 11)
Type A fillet welds (Table 9e): e ≥ ¾T (min 6 mm); f = T/2 (max 12 mm, min 8 mm); g = t for t ≤ 10 mm, or t/2 (min 10 mm) for t > 10 mm. T = neck/reinforcing-plate thickness, t = shell thickness.
2. Shell Nozzles (Table 10 — Fig. 12, 13)
3. Roof Manholes (Table 11 — Fig. 14)
4. Roof Nozzles (Table 12 — Fig. 15)
5. Drain Pad for Elevated Tanks (Table 13 — Fig. 17)
Opening shall be rectangular with upper corners radiused to at least ⅓ of the greatest clear-opening height; clear opening width or height shall not exceed 1200 mm (Note 1). The reinforced opening is completely preassembled into a first-course shell plate (Note 2). If any plate in the unit exceeds 16 mm, attachment welds shall be thermally stress relieved at 600–650°C for 1 h per 25 mm of thickness (Note 3).