18" Multi-Bolt Raised Manhole (Model #MB154-18R-A) - Painted Steel

The Model MB154-18R-A is engineered with a raised profile to lift the sealing boundary above the deck level. This prevents standing deck water, washdown runoff, and debris from pooling around the gasket, significantly lowering the risk of tank contamination. The multi-bolt pattern distributes compression forces perfectly across the perimeter flange, making it ideal for storage spaces subjected to high structural stress, pressure variances, or heavy liquid sloshing.

Intended Use Cases:

• Exposed Weather Decks: Ideal for installation on open work decks, forecastles, or poop decks where heavy seas or frequent washdowns create standing water.
• Ballast & Fuel Tank Access: Provides a high-integrity boundary seal for liquid cargo, fuel oil storage, and water ballast tanks.
• Machinery Space Protection: Guards below-deck dry voids, cofferdams, and engineering spaces against accidental water ingress from above.

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.
• 16-Bolt Perimeter Security: Utilizes a rugged, 16-point heavy-duty bolt pattern around the circumference to deliver uniform, high-torque gasket compression and maximum pressure retention.
• 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.
• Ships as a Complete System: Sold as a complete, ready-to-install assembly containing the cover plate, raised deck coaming frame, and all necessary closure bolts.

• 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.