3) Fusible plug • Function: To extinguish fire in the event of water level in the boiler shell falling below certain specified limit. • It protects fire tubes from burning when the level of the water in the water shell falls abnormally low and the fire tube or crown plate which is normally submerged in the water, gets exposed to steam space which may not be able to keep it cool. • It is installed below boiler's water level. • When the water level in the shell falls below the top of the plug, the steam cannot keep it cool and the fusible metal melts due to over heating. Clear Qam Program Guide. Thus the copper plug drops down and is held within the gunmetal body by the ribs. Thus the steam space gets communicated to the firebox and extinguishes the fire. Thus damage to fire box which could burn up is avoided.

• By removing the gun metal plug and copper plug the fusible plug can be put in position again by interposing the fusible metal usually lead or a metal alloy. Trane Hvac Design Manual Pdf on this page. 4)Safety Valve Function: The function of safety valve is to release the excess steam when the pressure of steam inside the boiler exceeds the rated pressure. There are 4 types of safety valves: i) Lever Safety Valve The disadvantage of this valve is that it admits of being tempered with, and the effect of a small addition to the weight is magnified considerably in its action on the value.

Mechanical Engineering Tutorials. Working and function of mounting & accessories in. Is to permit the steam in the boiler to escape to atmosp0here when. Mechanical Engineering Tutorials - This tutorial is to study Working and Function of mounting & accessories in boilers with detailed definitions.