Why safety valve is important in boiler?

The safety valve is one of the most important safety devices in a steam system. The main function of a safety valve is to relieve pressure. It is located on the boiler steam drum, and will automatically open when the pressure of the inlet side of the valve increases past the preset pressure.

What pressure does the steam drum vent must be close?

As the steam pressure reaches 2 kg/cm2 (above atmospheric pressure 1.03 kg/cm2), we can ensure that the air has been evacuated from the drum. therefore the air vent is closed to prevent the further loss of saturated steam.

What is the function of air vent?

Air vents are thermo static devices which remove the air from the system. Air mixed with steam lowers the temperature of the mixture which enables the air vent to remove the air.

What is Startup vent in boiler?

The vent valve kept open while start up boiler is called start up vent valve. This valve is usefull to vent low temperature & pressure moisturised steam. as well as to raise steam pressure slowly.

What is the function of air vent in boiler drum?

Air vents are provided on the boiler drum to evacuate the air and dissolved gases from the drum. During the boiler start up, the saturated steam will accumulate in the boiler drum and its pressure will start rising.The air and dissolved gases will be released through air vent.

Why does the pressure in a boiler rise when heated?

Heat is applied to the water in the tubes and drums, it starts to boil, steam is given off and expands. The expansion of steam tries to increase in volume but is constrained by the drum, the pressure therefore rises. Check your “whistling kettle” to see this in action! Pressure isn’t going to rise in the drum of a boiler.

How to prevent a boiler from collapsing while draining it?

Thanks for d suggestion@mariner ram sir.. Air vent valve also plays a significant role in preventing the boiler to collapse while draining the boiler.it prevnts the vacuum to be developed during draining .However it is to be kept in mind that vent valve is opened only when the boiler is cooled.

What is a balance in a boiler?

A boiler has a fixed size, ignoring expansion, start boiling the water and the pressure in the boiler rises. As the pressure rises it is harder for water to boil so a balance is reached between the amount of heat applied and the pressure generated.