Lancashire Boiler: Definition, Parts, Working, Applications, Advantages, and Disadvantages [PDF]

What is Lancashire Boiler?

Lancashire Boiler is a horizontal type and stationary fire tube boiler. This boiler was invented in the year 1844, by William Fairbairn. This is an internally fired boiler because the furnace used is present inside the boiler. This boiler generates low-pressure steam and it is a natural circulation boiler. It has high thermal efficiency of about 80 to 90 percent. The size is approximately 7-9 meters in length and 2-3 meters in diameter. It is mostly used in locomotive engines and marines etc.

Parts of a Lancashire Boiler

A Lancashire Boiler consist of following parts:

  • Safety valve
  • Pressure Gauge
  • Feed check valve
  • Water Level Indicator
  • Blow off valve
  • Steam stop valve
  • Manhole
  • Fire door
  • Fusible Plug
  • Ash pit
  • Economizer
  • Air preheater
  • Superheater
Lancashire Boiler
Lancashire Boiler

Safety valve

It is a crucial safety device that automatically releases excess steam pressure if it exceeds the boiler’s maximum safe limit. It prevents the boiler from exploding.

Pressure gauge

It is used to measure and display the steam pressure inside the boiler. This helps in monitoring and controlling the boiler’s pressure within safe operating limits.

Feed check valve

This valve allows the entry of water into the boiler. It ensures that water flows in only one direction, preventing backflow. Thus maintaining a consistent water supply.

Water level indicator

It is used to indicate the water level inside the boiler. It helps operators ensure that the boiler is adequately filled with water. It prevents damage due to low water levels.

Blow off Valve 

This valve is used to discharge impurities, sediments, and sludge that accumulate at the bottom of the boiler. It helps maintain the efficiency and performance of the boiler.

Steam stop valve 

It is a manual valve used to control the flow of steam from the boiler to the steam pipes. It can be used to start or stop the supply of steam to various processes or equipment.


It is a large opening on the boiler’s shell that allows access for maintenance and inspection purposes. It provides a way to enter the boiler for cleaning, repairs, and internal examinations.

Fire door

It is an opening through which fuel, typically coal or biomass, is fed into the furnace of the boiler. It allows for the control of combustion and the introduction of fuel into the combustion chamber.

Fusible plug

This is a safety device placed in the furnace crown sheet. It contains a fusible alloy that melts at a specific temperature. When the water level drops too low, the plug melts, allowing steam and hot gases to escape, alerting operators to take necessary action.

Ash pit

It is a compartment located beneath the furnace where ash and unburned residues from the combustion process are collected. It provides an area for the removal of ash without interrupting boiler operation.


An economizer is a mechanical device that is used as a heat exchanger in the steam power plant. It is used to pre-heat the fluid or water by taking the residual heat from the combustion products( flue gases). It is installed to increase the efficiency of the boiler. 

Air pre-heater

It is another heat exchanger that preheats the air required for combustion by utilizing the waste heat from the flue gases. This increases the efficiency of the combustion process and reduces fuel consumption.


It is a component that further increases the temperature of the steam produced in the boiler by removing moisture and increasing its energy content. Superheated steam has various industrial applications requiring high-temperature steam.

Working Principle of Lancashire Boiler

A Lancashire boiler works on the basic principle of the heat exchanger. It is basically a shell and tube type heat exchanger in which the flue gases flow through the tubes and the water flows through a shell. The heat is transferred from flue gases to the water through convection. It is a natural circulation boiler that uses the natural current to flow the water inside the boiler.

Lancashire Boiler
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Applications of Lancashire Boiler

Lancashire Boiler can be used in several fields which are as follows:

  • The Lancashire boiler is used to drive steam turbines, locomotives, marines, etc.
  • It is used in industries like paper industries, textile industries, sugar industries, tire industries, etc.

Advantages of Lancashire Boiler

Following are some advantages of Lancashire boiler:

  • This has high thermal efficiency of about 80 to 90%.
  • This is easy to operate.
  • It can easily meet the load requirement.
  • Easy to maintain.
  • Low consumption of electricity due to natural circulation.

Disadvantages of Lancashire boiler

A Lancashire boiler has some disadvantages which are as follows:

  • This is a low-pressure type boiler, so high-pressure steam is not produced.
  • It has a limited grate area due to the small diameter of the flue tubes.
  • The steam production rate is low. It is about 9000 kg/hr.
  • Corrosion occurs in the water legs.
  • Lancashire Boiler requires more floor space.

Video on Lancashire Boiler

Credit : Magic Marks


How is lancashire boiler manhole cover secured?

The manhole cover of the Lancashire boiler is usually made from cast iron or steel. It is designed to withstand high pressure and temperature. The cover is placed over the opening on the top of the boiler. It is secured in place using a set of bolts that are threaded through the cover and into the flange on the boiler shell. Once the bolts are tightened, they create a secure seal that prevents steam from escaping from the boiler. To ensure that the manhole cover remains secure, it is important to check the bolts regularly for signs of wear or damage. If any bolts are found to be loose or damaged, they should be replaced immediately to prevent any leaks or accidents. Proper maintenance and regular inspection of the manhole cover can help to ensure the safe and efficient operation of the Lancashire boiler.

when does lancashire boiler leak water?

One of the most common reasons for a Lancashire boiler to leak water is corrosion. Corrosion can occur due to the presence of impurities in the water that react with the metal of the boiler over time, causing it to weaken and eventually leak.
Another reason for water leaks in a Lancashire boiler could be due to damaged or worn-out gaskets and seals. These components are critical for maintaining a tight seal between the different parts of the boiler, and if they are damaged, it can lead to water leaks.
Poor maintenance can also lead to water leaks in a Lancashire boiler. Regular inspection and maintenance of the boiler can help identify any issues early on and prevent them from becoming more severe. It is essential to follow the manufacturer’s guidelines for maintenance and cleaning of the boiler to ensure its optimal performance and longevity.

Who installs lancashire boiler?

The installation of a Lancashire Boiler requires specialized knowledge and expertise. It is a type of fire-tube boiler that is widely used in industrial applications. The installation process involves setting up the boiler, connecting it to the necessary piping systems, and ensuring that it is operating efficiently and effectively.


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