Deck Seal

Deck Seal (type: semi dry)

The above image is of tanker ship. In the image you can easily see the semi dry deck seal. In this article I am going to explain how this deck seal work. The IG (inert gas) which is treated flue gas of boiler combustion is go through the deck seal. Deck seal also act as a non-return valve. Before the non-return Isolation valve is also provided. The pressure in the deck line is measured in millimeters of Wg (water gauge) or in short (mmWg). In the normal condition water is flowing in deck seal by the help of weir integrated in the deck seal. This weir has essential purpose maintain a level of water in deck seal. When IG is not coming or generating from Engine Room (E/R) the Kinematic Valve is open. Also the water to present in U bend (or seal of pipe). As soon as the IG comes it closes the kinematic valve also displaces the water present in the U bend and then goes out from deck seal above pipe  I will draw a line of grey color that will show the path when IG is passing through deck seal. Also I will show what will be the case if IG is not passing.

The mounting on our ship of deck seal are

1.       Float switch

2.       SW Inlet and Outlet

3.       Steam Inlet and Outlet

4.       Drain Valve

5.       Kinematic Valve

6.       Sight Glass (It must be half of glass)

7.       Outlet line for sea water (it is going in Pump Room) I think so.