DieselShip's Online Content Library

Q5. With reference to boiler feed water systems:

a) Describe the relationship between density and relative density. (4)

b) Describe what is meant by total dissolved solids (TDS). (4)

c) Explain why a high TDS is detrimental to a steam plant system, and how it is controlled. (4)

d) State TWO faults that may cause the total dissolved solids to reduce. (4)

Q5. List FOUR safety or alarm devices fitted to an automatically controlled auxiliary boiler indicating how EACH of these devices may be tested. (16)

Q5. (a) State the name given to the water level indicators mounted on a boiler. (2)

(b) State why at least two of the items stated in (a) are fitted. (4)

(c) List FIVE boiler mountings which are subject to survey, other than those stated in (a). (10)

Q5. With reference to auxiliary boilers:

(a) Explain how scale forms on the heating surfaces (8)

(b) State TWO reasons why scale is undesirable (4)

(c) State how scale build up is prevented from forming in steam boilers (4)

Q5. Describe, with the aid of sketches, the procedure for testing a boiler gauge glass (16)

Q5. List EIGHT mountings which must be present on auxiliary marine boilers. (16)

Q5. With reference to an auxiliary boiler. state for EACH of the following circumstances the action to be taken, giving a reason for EACH action:

(a) No water level visible in gauge glass (4)

(b) Safety valve lifting (4)

(c) Excessive smoking during firing (4)

(d) Excessively high chloride content of boiler water. (4)

Q5. (a) State the consequences of not testing or treating the water in a boiler. (4)

(b) For a fire tube auxiliary boiler

(i) Explain how scale may form on the heating surfaces. (4)

(ii) State FOUR tests which are usually carried out on the boiler water (8)

Q5. With reference to auxiliary boilers:

(a) State the effect on operation in the event of EACH of the following conditions:

(i) High water level; (2)

(ii) Low water level; (2)

(iii) Extra-low or low-low water level. (2)

(b) Describe the procedure for verifying the water level in a low-pressure boiler gauge glass. (10)

Q5. State the possible cause, and outline the remedial action that should be taken when EACH of the following faults occur during starting of an automatic package boiler:

(a) The boiler starts and the fan runs with the control dampers correctly positioned, the boiler then locks out before purging is completed. (4)

(b) The boiler purges correctly, but the ignitors fail to spark, and the boiler locks out (4)

(c) The boiler purges correctly, the ignitors spark, but the boiler fails to light up and locks out. (4)

(d) The boiler flame flashes up but after about 5 seconds the automatic control locks the boiler out. (4)