Marine Hatch Cover

 Marine Manhole

Marine Hatch Cover

Definition

In order to prevent the water into ships, installed on the hatch wooden or steel cover, also can be used as supporting structure of cargo deck, called hatch cover .According to the requirements of general tightness, divided into water tight hatch cover, oil tight hatch cover and non tight hatch cover.

Hatch cover main role is to ensure that waves and rain do not invade the cargo hold, some hatch cover also bear weight of cargo on deck.

small hatch cover installed in liquid cargo warehouse, refrigerated cargo warehouse , personnel access hatch and manhole

According to the transmission mode divided into rolling hatchcover l, oblique type, sheathed type, roll shift including lateral displacement type, cascade, roll roll type, hinge type including hinged flap, folding and so on.

With tightness hatch can devide into watertight, oiltight, airtight and nontight hatchcover etc., according to the different tightness that hatch cover plate and the adjacent components are respectively equipped with layering, packing, gasket, pressing device sealing apparatus.

classification

According to the hatch size, divided into large and small hatch cover. The former is used for bulk cargo loading, material or vehicle cargo, cabin hatches; the latter is used for loading liquid cargo, refrigerated cargo and personnel entrance hatch and manhole.

According to hatch cover plate material and type have assembly wooden or metal hatch cover, Box type hatch made by metal or glass. Small hatch cover generally open and close by human, large hatch cover must use electric or hydraulic driven mechanical opening and closing.

According to the transmission mode can be divided into rolling hatch cover ,verrtical type, oblique type, sheathed type, roll shift including lateral displacement type, cascade, roll roll type, hinge type including hinged flap, folding and so on.

According to tightness with water tightness, oil tightness,gas tightness and non tight hatch cover etc., according to the different tightness that hatch cover plate and adjacent components are respectively equipped with composed of layering, packing, gasket, pressing device of sealed cabin device or sealing device.

1.Weathertight cargo hatch cover

Cargo hatch in the freeboard deck must steel weathertight hatch cover.

2.Oil sealing cargo hatch cover

Cargo hatch cover not install in conceal place,should not be less than 600 mm * 600 mm. Measurement hole diameter not less than 150 mm and observation hole hatch. The hole should ensure effective oil tight cover closing device. The opening of cargo hatch usually made of round or oval.

3.Non watertight hatch cover fit cargo and residential

Under cabin deck hatch without coaming, hatch cover parallel with around.

Hatch design requirements

1.The structural strength of all open deck hatch cover should be adjacent to around structure.;

2, Hatch cover closure device should ensure the weathertight;

3,The vehicle deck hatch cover if under vehicle load, hatch cover design pressure should be by vehicle load values of the strength check.

Weathertight hatchcovers installation inspection

Door, window,cover are small weathertight closing devic. Because the number much, the shipyard during installation random checks, include:

1.Look up Small weathertight hatchcovers marine product certificate, and check the real stamp or mark.

2.The opening position according to the approved classification review drawings inspection cover. Particular attention should be given to the freeboard deck Small weathertight hatchcovers, for Small weathertight hatchcovers, focus on examination deck height.

3.The cover is installed, check the structural integrity, durability and performance of headstock.

4.The welding quality check.

5.Check door ,window, cover tightness. General installation quality pigment adhesion method check the seal, then after installation, flush test according to the classification society.

Steel watertight cargo hatch cover test

Steel cargo hatch covers is an important hull outfitting equipment, which is used to hatch cover and protect the cabin and goods from invasion of wind and rain. When the ship loading and unloading of goods, can be easily opened or closed, the cargo hatch covers should have enough strength, to ensure under waves or other set of load not deformation, effect use.

Steel watertight cargo hatch cover generally with shipyard's quality inspection department inspection certificate, should accordance with classification society, apply ship inspection of product ,during manufacturing process to surveyor and ship owner submit acceptance and inspection of steel watertight cargo hatch covers. Classification society give certificate to acceptable covers.

Steel watertight cargo hatch covers installation inspection has two contents: ship hatch coaming installation inspection; hatch cover at coaming installation inspection and test.