Marine Manhole Cover

Marine Manhole Cover

Introduction

Manhole cover is a general term for the cover plate with sealing performance and its fixing accessories installed on the manhole. Marine manhole covers can be divided into oblong and round shapes according to their shapes, among which oblong manhole covers are widely used. According to its tightness, it can be divided into oil-tight and water-tight. The difference between the two is the material of the sealing gasket. Oil-tight should be made of oil-resistant rubber, and water-tight should be made of sea (fresh) water-resistant rubber.

Marine Manhole Cover
Steel Manhole Cover	Aluminum Manhole Cover

Main Material

The cover plates, coaming plates and seat rings of the manhole cover are usually made of hot-rolled carbon steel or made of the same material as the hull structure where the manhole cover is installed, gaskets and handles are made of ordinary carbon steel, sealing gaskets are made of flame retardant oil-resistant or sea (light) water-resistant rubber, bolts or studs are made of stainless steel or carbon steel, nuts are made of carbon steel, stainless steel or brass. Bolts, studs, nuts and gaskets made of carbon steel should be galvanized.

Parts

Configuration Option

Part name	Material	Pros & Cons
Cover plate	AL6063	Good plasticity, moderate heat treatment strength, good welding performance and gorgeous color on the surface after anodizing treatment.
	Q235-A	Good toughness and plasticity, certain elongation, hot workability. Welding performance is weak than Q235-B
	Q235-B	Good welding performance, Good low temperature toughness
Seat&Coaming	AL6063	Good plasticity, moderate heat treatment strength, good welding performance and gorgeous color on the surface after anodizing treatment.
	Q235-A	Good toughness and plasticity, certain elongation, hot workability. Welding performance is weak than Q235-B
	Q235-B	Good welding performance, Good low temperature toughness
Handle	SUS304	Sturdy and not easy to damage, and resistant to seawater corrosion
	Q235	Good welding performance, Good low temperature toughness
Sealing	Neoprene rubber	Excellent Watertight performance
	Butadiene rubber	Excellent oil resistance, abrasion resistance and air tightness

Comparison differences

Other manufacturer’s low quality manhole cover	HI-SEA high quality manhole cover
1. The material used for manhole cover plate has high carbon content, low hardness and thin brittleness. two。. Manhole cover surface improper handling, not anti-rust, and the appearance is not beautiful. 3. The handle is made of cheap carbon steel, which is easy to rust and damage and has high maintenance cost. 4. The sealing material has poor flexibility and is prone to deformation, fracture and corrosion. 5. The welding process of the parts is not good, the service life of the hatch cover is shortened, and brittle fracture may occur seriously.	1. The manhole cover is made of high-quality steel and aluminum with a solid and stable structure. two。. The hatch cover has excellent welding technology and long service life. 3. The use of high-quality sealing materials, good sealing performance and not easy to deform. 4. The hardware parts are made of high-quality stainless steel 316, which is strong and resistant to corrosion. 5. The certificate of each classification society is complete, which can meet the different needs of customers. 6. The product provides installation instructions.

Drawings

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