Home > Boiler Capacity > 3ton/4ton Boiler >

3 ton/4 ton Oil/Gas Fire Tube Boiler

Capacity : 0.5~20t/h

Pressure : 0.7/1.0/1.25/1.6Mpa

Fuel : Heavy oil, Diesel, Natural gas, Bio-gas lpg/Lng, etc.

Application : Medicine, chemical, light industry, textile, building material, food processing, laundry, hotel, etc.

Brief Intro : WNS boiler is a safe and high efficiency (98%) heating equipment with high automation, it is fast assemble boiler with flue gas three pass and wet back structure, widely used for industrial production.

Email:   [email protected]

>> Smoke gas three pass
WNS series gas oil fire tube steam boiler is a kind of safe and high efficiency heating supply equipment with full automatic control system. It is one patent product of Sitong Boiler, the patent number is 2014 2 0504448.2. This series oil gas fired boiler is horizontal type fast assembly fire tube boiler with three pass structure, it has compact structure, small water volume, strong load adaptability and low water quality requirement etc.features.
Smoke gas three pass
The flaming torches formed by burning the fuel is filled in the corrugated furnace through the burner and transfer radiant heat through the furnace wall, This is the first-pass.
The high-temperature flue gas generated by the combustion gathers in the back-combustion chamber and turns into the second pass(i.e: the threaded tube bundle region). After the convective heat exchange, the flue gas temperature is gradually lowered to the front smoke box.
The third-pass boiler flue gas is diverted from the front smoke box to the long thread smoke tube, and then enters into the economizer and the condenser through the rear smoke box, and finally flows into the chimney, discharges into the atmosphere.
>> Features
Fully wet back combustion chamber

1. Fully wet back combustion chamber

The reburning chamber abutting with the rear tube plate, boiler is 100% fully butt welded, lower stress, and reliable quality.

2. Large-diameter corrugated furnace

The boiler combustion chamber is composed of large-diameter corrugated furnace, larger combustion space, completed combustion, larger heating area, higher thermal efficiency.
Fully wet back combustion chamber
Multi-functional anti-explosion device

3. Multi-functional anti-explosion device

The boiler rear plate equip with anti-explosion device which connected to the furnace, it can release the pressure and self-reseted once fuel deflagration in the furnace. At the same time, it has the function of fire watching and inspection.

4. High thermal efficiency

The economizer was equipped at the rear of boiler, which can reduce the exhaust gas temperature and increase boiler feed water temperature,improve efficiency can reach to 96% (fuel: natural gas ).
High thermal efficiency

>> Parameter

Steam Boiler


Rated evaporation

capacity (t/h)

Rated steam 

pressure (Mpa)

Thermal efficiency 


Fuel consumption

Overall dimension 




Body Heating 

Area (m2)

Light oil (Kg/h) Natural gas (Nm³/h)
WNS1-1.0/1.25-Y(Q) 1 1.0/1.25 >90 66.5 75 3.6×2.0×2.0 4 25
WNS2-1.0/1.25-Y(Q) 2 1.0/1.25 >90.2 133 150 4.8×2.5×2.46 8 60
WNS4-1.0/1.25-Y(Q) 4 1.0/1.25 >91 266 300 5.8×2.85×2.8 13 113
WNS6-1.25/1.6-Y(Q) 6 1.25/1.6 >91.5 399 450 7.25×3.1×3.15 19 181
WN8-1.25/1.6-Y(Q) 8 1.25/1.6 >91.6 532 600 7.45×3.26×3.2 22.6 190
WNS15-1.25/1.6-Y(Q) 15 1.25/1.6 >91.8 997 1125 8.7×3.7×3.5 34 346
WNS20-1.25/1.6-Y(Q) 20 1.25/1.6 >92 1204 1418 10×3.6×4.0 45 467
Note: Parameter is for reference only, we can design the boilers based on customers’ needs.

Hot Water Boiler

Model Rated Power (MW) Working Pressure (MPa) Efficiency (%) Fuel consumption Weight (kg)

Overall Dimension

 Length×Width×Height (mm)

Light Oil (kg/h) LNG (Nm3/H) CG (Nm3/H)
WNS 1.05-95/70-Y(Q) 1.05 0.7 91~93 98.5 119.4 253.7 3400 3500×1800×2050
WNS 1.75-95/70-Y(Q) 1.75 1.0 91~93 164.2 198.9 422.8 4800 4500×1950×2300
WNS 2.1-95/70-Y(Q) 2.1 1.0 91~93 197 238.7 507.3 6682 4800×2000×2500
WNS4.2-95/70-Y(Q) 4.2 1.0 91~93 394 477.5 1014.6 12400 7850×2750×3460
WNS7-95/70-Y(Q) 7 1.0 91~93 656.7 795.8 1691 15300 8600×3770×4150

Note: 1. The heat value of LNG: 8500kal/Nm3, heat value of light oil: 10300kal/Nm3, heat  value of the city gas: 4000kal/Nm3 

2. Parameter is for reference, if any changes, should follow the actual drawing.

>> Projects
    Oil Gas Fired Boiler
    Coal Boiler
    Biomass Boiler
    Thermal oil Heater
    CFB Boiler
    EGB Boiler
    Hot water/oil Steam
    0.7-14 MW
    14.1-21 MW
    21.1-29 MW
    29.1-75 MW
    1-10 t/h
    11-20 t/h
    21-90 t/h
    91-140 t/h

    Sitong Boiler Co., Ltd is the professional manufacturer of Grade A industrial boilers, engages in industrial boiler design, manufacturing, transportation, installation, and after-sale service.

    Online Chat
    chat online
    send email

    [email protected]

    send WhatsApp


    back top