Discussion on Selection of Boiler Explosion-Proof Doors

September 23, 2022

When the boiler uses biomass as fuel, if the operation is improper, it is very likely that the furnace will deflagrate together, or even a partial explosion of the boiler may occur, causing great damage. Therefore, in addition to the safety interlock protection device, the boiler must also be equipped with explosion-proof doors in the furnace area, flue area and other areas to reduce the damage to boiler equipment caused by deflagration or explosion.

The scope of application of explosion-proof doors


The types of boilers that usually require explosion-proof doors are: pulverized coal boilers, gas/oil-fired boilers and biomass-fired boilers.


Pulverized Coal Boiler

Explosion-proof doors should be set in the coal mill, pulverized coal silo and flue. In addition, explosion-proof doors should also be set at the furnace.


Fuel Gas Boiler

Set explosion-proof doors in the furnace area and the flue area where combustible gas is easy to accumulate.


Biomass Fired Boiler

Set explosion-proof doors in the furnace area and the flue area where combustible gas is easy to accumulate.


Types and introduction of commonly used explosion-proof doors


1. Gravity explosion-proof door

2. Spring-loaded explosion-proof door

3. Diaphragm type explosion-proof door

4. Water-sealed explosion-proof door



Characteristics of different types of explosion-proof doors

1.Gravity explosion-proof door

Advantages: The structure and manufacture are relatively convenient, and it can be reset automatically after pressure relief, which is widely used in oil-fired gas boilers.

Disadvantages: It is difficult to seal, and it is easy to cause air leakage.

2. Spring-loaded explosion-proof door

Advantages:It can be reset automatically, has good sealing performance, has a quick jump-off response, is suitable for different types of boiler products, and has low manufacturing difficulty and manufacturing cost.

Disadvantages: If the pressure generated by the deflagration is too large, the explosion-proof door will be damaged because it cannot withstand the impact.

3. Diaphragm type explosion-proof door

Advantages: simple structure, convenient design and manufacture.

Disadvantage: Once the diaphragm type explosion-proof door is activated, it cannot reset itself, and the tightening device must be opened to replace the diaphragm.

4. Water-sealed explosion-proof door

Advantages: The structure is simple to manufacture, and it has good sealing performance. It is used for boilers operating under micro-positive pressure.

Disadvantage: Once the pressure is released, the outer cylinder needs to be refilled with water. When the boiler is working normally, water needs to be replenished to ensure the water level of the outer cylinder is stable.



Different types of explosion-proof doors have their own characteristics. Therefore, different types of explosion-proof doors should be designed and selected according to different boiler furnace types, boiler fuel and operating conditions. At the same time, attention should be paid to the design calculation, installation, daily inspection and maintenance of explosion-proof doors.

EPCB,your private boiler system expert!

Further Reading:

Boiler Guidance----Acceptance After Boiler Installation

Industrial Boiler Low Load Operation Hazards,Causes and Solutions

Thermal Oil Boiler Safety and Energy Saving |Thermal Oil Boiler Scaling Causes, Hazards and Solutions

  • Send You Inquiry

  • Give You Boiler Solution

  • Place The Order

  • Get Your Boiler

Ask for Boiler Solution Suited Your Condition!

Tell us your need about boiler capacity in your industry, we will recommend the most suitable boiler model for you!

Consult online customer service
Boiler fuel: