18" Multi-Bolt Raised Manhole - Cover & Frame Only (Model #MB154-18R-X) - Painted Steel

The Model MB154-18R-X features the same heavy-duty raised profile and structural frame as our complete system, lifting the sealing boundary safely above deck level. It provides the flexibility to source project-specific fastening hardware—such as specialized high-strength alloys, specific grade fasteners, or quick-release toggles—while utilizing our standard, precision-machined marine cover and coaming layout.

Intended Use Cases:

• Custom Hardware Integration: Ideal for projects where engineering specifications require a specific grade, coating, or source of structural fasteners not included in standard assemblies.
• Structural Refits & Re-framing: Perfect for hull restoration where existing multi-bolt hardware is salvaged and a brand-new cover and welded coaming ring are required.

Primary Industries & Vessel Types:

• Inland & Ocean Barges: Heavily utilized on the deck flats of liquid cargo barges, hopper barges, and offshore material barges.
• Commercial Workboats & Tugs: Standard equipment for deep-sea tugs, push boats, and industrial supply vessels.
• Offshore Energy Platforms: Built to withstand the extreme weather and continuous salt-spray environments of offshore drilling and production platforms.

• Raised Coaming Profile: Features an elevated vertical frame wall that acts as a natural barrier against pooling water, mud, and debris on active work decks.
• Precision 16-Hole Layout: Pre-drilled 16-hole perimeter pattern aligns perfectly with standard industry bolt specifications for fast hardware matching and uniform stress distribution.
• Heavy-Duty Structural Steel: Fabricated from thick, high-tensile structural steel to prevent cover deformation and survive severe impact on commercial vessel decks.
• Buna-N High-Compression Gasket: Features a premium Buna-N (Nitrile) rubber gasket track providing excellent sealing performance and broad resistance to fuels, oils, and marine chemicals.
• Universal Shipyard Finish: Arrives shot-blasted and coated with a universal shipyard primer (painted), making the assembly completely ready for immediate welding and final coating at the shipyard.
• Hardware Exclusion Value: Ships with the structural steel cover plate and matching raised deck coaming frame only, minimizing unnecessary component costs when hardware is already supplied on-site

• Hardware Compatibility Check: Prior to installation, verify that your sourced fasteners perfectly match the thread clearance, depth, and structural load ratings required by the pre-drilled perimeter holes.
• Qualified Personnel Requirement: Installation must be performed by qualified marine welders or fitters in accordance with applicable classification society standards (ABS, DNV, Lloyd's) and specific hull blueprints.
• Surface Preparation & Alignment: The raised coaming frame must be aligned true and securely welded to clean, flat deck plating to prevent thermal warping or twisting of the perimeter sealing seat during fabrication.
• Bolt Thread Protection: Apply a premium marine-grade anti-seize compound to all bolt threads prior to final assembly to ensure smooth mechanical tightening and prevent future thread binding or galling.
• Perimeter Sealing Verification: Tighten all 16 bolts in a progressive, alternating star pattern rather than a circular sequence. This ensures perfectly even gasket compression and a uniform seal across the entire perimeter frame.
• Debris Inspection: Prior to closure, ensure that the gasket track, coaming rim, and internal tank lip are completely free of weld spatter, slag, rust, or heavy topcoat accumulation.