When installing and designing industrial boiler systems, the feed water tank is often viewed merely as a simple water storage vessel. However, in a mature thermal system, the configuration of the feed water tank ensures 

not only the continuity of the water supply, but also directly impacts the boiler’s service life, thermal efficiency and operational safety. Therefore, selecting an appropriately sized feed water tank for industrial boilers is critical.

I. The core functions of an industrial boiler feed water tank

• Buffering and continuous water supply

During boiler operation, the load fluctuates dynamically. As a reserve buffer tank, it ensures there is sufficient water in the boiler to maintain normal operation during brief periods of external water shortage or maintenance 

of water treatment equipment, thereby preventing dry firing.

• Preheating and thermal deaeration

By recycling condensate or introducing secondary steam, the feed water tank can preheat the cold water. This reduces thermal shock to the boiler body and removes dissolved oxygen from the water by raising its temperature. 

This reduces oxygen corrosion and extends the service life of boiler piping.

• Sedimentation and purification

Water entering the boiler requires softening treatment, and the tank serves as a secondary sedimentation basin, allowing minute impurities to settle at the bottom. Regular blowdown maintains the cleanliness of the feedwater.

• Balancing system pressure

When the feed water pump draws water from the tank, the tank maintains a certain static head. This prevents cavitation in the feed water pump and ensures stable pump operation.

II. What are the requirements for boiler tank size?

The capacity of a gas boiler tank should be determined based on the boiler’s makeup water volume. Typically, the system makeup water volume is calculated to be 3–5% of the boiler’s circulating water volume when 

designing a boiler.

III. How to address leaks in the boiler water tank.

Water tank leaks are a common boiler malfunction. If the make-up water tank overflows, this may be due to a malfunction in the check valve on the make-up pump’s outlet, which can cause backflow into the tank after 

the pump stops running. Additionally, if the float valve inside the tank fails to close automatically, this can also lead to overflow.

Selecting a water tank with a scientifically optimised configuration and high-quality materials is essential for the stable operation of gas-fired industrial boilers. For specific operating conditions (such as the makeup water 

and condensate recovery rates), we need to conduct customised design work for each project.