Hot-Dip Galvanized (HDG) bolted panel water tanks require a range of accessories to ensure functionality, safety, compliance, and longevity. Here’s a comprehensive list of common accessories, categorized by purpose:
1. Tank Structure & Assembly
Bolts, Nuts & Washers: High-strength galvanized steel fasteners (ASTM A325 or equivalent) with sealing washers.
Sealing Gaskets: EPDM or neoprene gaskets for watertight joints between panels.
Corner Plates & Reinforcement Kits: For structural integrity at corners and connections.
Anchor Bolts & Base Channels: To secure the tank to the foundation.
2. Water Management & Flow Control
Inlet Pipes: With strainers to prevent debris entry.
Outlet Pipes: Often with vortex breakers (essential for pump suction to avoid air entrainment).
Overflow Pipes: Sized ≥1.5× inlet diameter, directed away from the foundation.
Drain Valves: For complete tank drainage (ball valves common).
Manholes: Roof and/or wall-mounted (DN500–DN600) with gasketed, bolted covers for internal access.
Baffle Walls (for large tanks): Reduce water sloshing and sediment resuspension.
3. Ventilation & Protection
Ventilators (Breathers):
Mesh-Ball Vents: Prevent insects/debris entry while allowing air exchange.
Louvered Vents: For high-dust environments.
Insect/Vertebrate Screens: Stainless steel mesh for overflow/vent openings.
Lockable Access Covers: Security against tampering or contamination.
4. Water Quality & Corrosion Protection
Internal Linings (for potable water): NSF 61-certified epoxy or polyurethane coatings.
Sacrificial Anodes: Zinc/aluminum rods mounted inside to protect against corrosion (critical for stagnant water).
Sediment Traps/Sumps: Low-point drains to capture sludge.
Water Level Indicators: Gauge glasses or electronic sensors.
5. Safety & Access
Internal/External Ladders:
Caged Ladders: OSHA-compliant external access (for tanks >20 ft/6 m tall).
Internal Ladders: For maintenance (corrosion-resistant design).
Safety Rails & Platforms: Roof guardrails and work platforms.
Anti-Vortex Plates: Prevent air suction at outlets.
6. Inspection & Maintenance
Sample Taps: For water quality testing.
Cleaning Hatches: Smaller access points for hose entry.
Overflow Alarm Systems: Notify of overfilling.
Cathodic Protection Test Points: Monitor anode effectiveness.
7. Optional/Specialized Accessories
Insulation Kits: For freeze protection or temperature control.
Mixing Systems: Aerators or agitators to prevent stagnation.
Roof Support Columns: For large-diameter tanks (>15m).
Seismic Bracing/Kits: For earthquake-prone zones.
Bird Deterrents: Spikes or nets to prevent nesting.
Key Considerations:
Material Compatibility: All accessories must be galvanized or stainless steel (AISI 304/316) to avoid galvanic corrosion.
Standards Compliance:
Potable Water: NSF/ANSI 61, WRAS, EN standards.
Fire Protection: NFPA 22 requirements (e.g., screened vents, seismic design).
Customization: Accessories should match tank dimensions/loads (e.g., roof manholes rated for worker weight).