LAB EXPERIMENT 02

BOILER MOUNTING AND ACCESSORIES AND TESTING THE GAUGE GLASS

PERFORMANCE/OBJECTIVES

Identifying Boiler mountings and accessories in a steam plant. Testing the gauge glass.

TOOLS:

Boiler Mechanical tools Gauge glass

THEORY:

BOILER MOUNTING:

FEED CHECK VALVE:

It controls the supply of water from the boiler when the feed pump pressure is less than boiler pressure or pump is stopped.

WATER LEVEL INDICATOR:

It indicates the water level inside the boiler vessEL. It shows the water level in the boiler drum

STEAM CHECK VALVE:

It regulate the flow of steam from boiler to the steam pipe or from one steam pipe to the other.

PRESSURE GAUGE:

It indicates the pressure of steam in boiler.

Name: _____________________________________________ ID No. ____________________

Score: ________________ Signature of the lab tutor_______________ Date:_________________

FUSIBLE PLUG:

It is use to protect the boil against damage due to overheating caused by low water level in the boiler.

BLOW OFF VALVE:

The function of blow off cock is to discharge mud and other sediments deposited in the bottom‐ most part of the water space in the boiler, while boiler is in operation. It can also be used to drain off boiler water. Hence it is mounted at the lowest part of the boiler. When it is open, water under the pressure rushes out, thus carrying sediments and mud.

SAFETY VALVE:

Safety valves are located on the top of the boiler. They guard the boiler against the excessive high pressure of steam inside the drum. If the pressure of steam in the boiler drum exceeds the working pressure then the safety valve allows blow off the excess quantity of steam to‐ atmosphere. Thus the pressure of steam in the drum falls. The escape of steam makes a audio noise to warm the boiler attendant.

BOILER ACCESSORIES:

These are auxiliary plants or parts required for steam boilers for their proper operation and to increased efficiency of the boilers

FEED PUMP:

The feed pump is a pump which is used to deliver feed water to the boiler.

INJECTOR:

Injector is used to feed water in the boiler.

ECONOMIZER:

Economizer increases the temperature of feed water using waste of heat as flue gases leaving the boiler through chimney.

SUPER HEATER:

The function of super heater is to increase the temperature of the steam above its saturation point.

AIR PREHEATER:

An air preheater is a general term to describe any device designed to heat air before another process (for example, combustion in a boiler) with the primary objective of increasing the thermal efficiency of the process. They may be used alone or to replace a recuperative heat system or to replace a steam coil.

STEAM SEPERATOR:

A Steam separator, sometimes referred to as a moisture separator, is a device for separating water droplets from steam. The simplest type of steam separator is the steam dome on a steam locomotive. Stationary boilers and nuclear reactors may have more complex devices which impart a "spin" to the steam so that water droplets are thrown outwards by centrifugal force and collected.

PROCEDURE:

To change the glass gauge of the boiler following steps will be done as follows:

1. Close the water valve to the gauge glass.2. Close the upper steam valve to the gauge glass.3. Open the gauge glass blow down valve.4. Remove the gauge glass nuts.5. Remove the gauge glass and washers.6. Taking the precautions wear gloves and eye covers.7. Install the new gauge glass and washers this must cut to fit allow one quarter inch un

breathing measurement for expansion by heat then tight the gauge glass nut taking the quarter turn to each.

8. Slightly open the steam check valve to allow the gauge glass to warm slowly.9. Close the gauge glass blow down valve10. Open the steam valve completely.11. Open the water valve completely.

EXPERIMENT RESULTS / OBSERVATIONS

Hence we learn about the mounting and accessories of boilers and the changing of glass gauge generally known as water indicator.