Important questions to discuss on marine boilers

1. Different reasons for boiler carryover.
    

A.     1. Adding of excessive phosphate.(to much chemicals in boiler water).

         2. Boiler water level is too high.

         3. Stains of oil in boiler water.

         4. Due rolling and pitching.

         5. If demister function is not well.

2. What are the internal mounting in boiler?

A.    1. Distributor and Ring - water enters into the boiler from main feed check valve through                        distributor & ring to avoid the thermal stresses in boiler.

        2. Demister - Prevents any carryover from boiler.

        3. Funnel - scum blow down takes place.

3. Types of ESD boilers? 

    

A.       There are three types: in each type we control the degree of super heat in different ways.

           In ESD - 1 type with help of control air flow. 

           In ESD - 2 type by flap control in boiler uptake.

           In ESD - 3 type with help of valve which allow required steam to go to heat the boiler water               and remaining bypass.

4. Safeties of boiler gauge glass?

A.    In the boilers gauge glass the cock of water side and  steam side opens vertically downward, not          horizontal because because due to vibration there will be a possibility that cock closes                          automatically if it open horizontally thus it may give wrong readings of water inside the boiler.
        On water side a hollow steel ball is present, in case of gauge glass breaks in between boiler                  operation to prevent the outflow of water with high temperature the steel ball shuts the flow of            water.

5. Blow through of gauge glass?

A.   Blow through of gauge glass should be carried out on daily basis 

        1. First shut the steam side.
        2. second shut the water side.
        3. open the drain cock at the bottom.
        4. now wait till gauge glass became empty.
        5. Open the steam side, let the steam drains and clears the steam side.
        6. close the steam side and open the water side, let the water drains completely and make the                  water side is clear.
        7. Now shut the drain.
        8. Open the water side and wait till water rise completely in the gauge glass.
        9. Open the steam side to check correct level of water in the boiler.

6. Purpose of some of the boiler safety valve parts?

A.  Easing Gear : easing gear purpose is to confirm that all the parts are lifted properly without any          stuck inside the safety valve.
      Blow down ring : Blow down valve purpose is to make sure that safety valve should not act like        relief valve. ( for relief valve if set the set pressure as 7 bar then the valve sits at below the set              pressure at 6.5 bar). so with this ring we set the blow down pressure, if we set the too high we              will excessive steam or if we set at very low then chattering effect will be there.
      Lip Clearance : The purpose of lip clearance is made for valve lid to sit completely on seat or if        lip clearance is zero then the valve lid cannot seal or close completely.
      Compression Nut : Sets the pressure for safety valve when to lift.
      Split Collar : The purpose of using this no one can change the lifting pressure of safety valve.
      Floating Ring : we can find this float ring in new type of safety valve, purpose is to make                  exhaust steam piston move freely with the help of floating ring. (in previous type of safety valve        after long term usage the exhaust steam piston stuck and safety valve setting pressure will be              effected).