Horizontal Three Pass Wet Back Boiler
WNS gas/oil boiler adopts horizontal fire tube structure, which can provide larger steam/water output. Three pass wet-back design, larger corugated furmace, thread smoke tube with unique expansion welding technique, high quality and environmental protection.
| Output: | Steam, Hot-water |
| Capacity: | 0.1ton-40ton, 100kg-40000kg, 99kw-28000kw |
| Work Pressure: | 3-38bar, 0.3-3.8Mpa |
| Heat Temperature: | 0-450℃ |
| Applied Industry: | Food, Beverage, Feed, Textile, Paper, Chemical, Package, Refinery, Pharm, Building Material, Hotel... |
Introduction
Yuanda Boiler, Over 70 Years in Boiler Design, Manufacturing, Installation, and Turn-key Boiler System Solutions. We provide complete boiler systems & auxiliaries for continuous steam & hot water supply.
Our Gas/oil Boiler Include: Horizontal Fire Tube Boiler (WNS) Vertical Fire Tube Boiler (LHS) Vertical Water Tube Boiler (LSS) D-type Water Tube Boilers (SZS)

WNS boiler is a automatic, horizontal gas or oil fuel fired boiler with three pass return fire tubes, also known as packaged fire tube boiler. It adopts bigger corrugated furnace, "wet-back" reversal chamber structure.
● Food & Beverage: Clean steam for cooking, sterilization, drying, packaging.
● Chemical & Pharmaceutical: Steam for synthesis, drying, sterilization, distillation.
● Textile & Dyeing: Thermal energy for dyeing, printing, drying, finishing.
● Paper & Packaging: Steam for pulping, drying, corrugating, production.
● Rubber & Plastics: Steam for vulcanization, molding, drying, calendering.
● Building Materials & Tobacco Industry: Steam for autoclave curing, drying, concrete production / tobacco production.
● Industrial Manufacturing: Steam/hot water for metal, plastic, electronics processing.
● Central Heating & Public: Hot water/steam for district heating, mining, hotels, hospitals, schools.
✅ High Security, 100% Safe Operation
1. PLC intelligent controller with HMI touch screen
2. Anti-dry heating system with 6-levels automatic water level protection
3. 8-level pressure regulating protection
4. Explosion-proof door with fire viewer
5. Attached Hydrostatic Test Report Strength calculation data sheet, Certificate of Quality, Quality and Safety Inspection Certificate, Installation and Operation Instruction etc.
✅ 98.6% High Efficiency, Save Fuel & Running Cost
1. Large corrugated furnace, patent design thread smoke tubes
2. Built-in steam separator, ensure high steam quality with wetness below 1%
3. Double 12cm thickness aluminum silicate insulation layer
4. Finned tube design economizer with aluminum silicate insulation, greatly reducing heat loss
5. Equipped with imported European modulating burner
✅ Long Using Life and Convenient for Maintenance
1. Fully water-cooled reversal flame chamber
2. Solid round steel tension rod design
3. Rapid solidification and high-strength refractory building materials
4. Double opening-door at front and back, manhole, and two hand holes etc
Boiler System & Accessories
Each gas/oil fired boiler is delivered as a packaged unit and includes:
① Boiler body ② PLC control cabinet ③ Top-brand burner ④ Water treatment & tank ⑤ Pressure gauge and pressure controller ⑥ Safety valves ⑦ Blowdown System ⑧ Frequency water pumps ⑨ Chimney &ducts ⑩ Steam header ⑪ Economizer
Optional Upgrades:
RO Water Treatment Equipment/Condenser/Low-NOx burner/Deaerator/Automatic chemical treatment system/TDS system etc

Parameter
| Model |
Rated steam output (Ton/hr) |
Rated steam pressure (Mpa) |
Rated steam temperature (℃) |
Feed water temperature (℃) |
Fuel consumption | |
| Light diesel oil(kg/h) | Natural gas(Nm3/h) | |||||
| WNS 0.5-0.7/1.0/1.25-YQ | 0.5 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 32.5 | 35.7 |
| WNS 1-0.7/1.0/1.25/1.6-YQ | 1 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 64.6 | 70.1 |
| WNS1.5-0.7/1.0/1.25/1.6-YQ | 1.5 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 96.8 | 105.2 |
| WNS 2-1.0/1.25/1.6-YQ | 2 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 129.3 | 140.3 |
| WNS 3-1.0/1.25/1.6-YQ | 3 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 192.9 | 212.1 |
| WNS 4-1.0/1.25/1.6-YQ | 4 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 258.2 | 283.4 |
| WNS 5-1.0/1.25/1.6-YQ | 5 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 323.5 | 354.7 |
| WNS 6-1.0/1.25/1.6-YQ | 6 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 388.6 | 424.2 |
| WNS 8-1.0/1.25/1.6/2.0-YQ | 8 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 514.6 | 566.3 |
| WNS 10-1.0/1.25/1.6/2.0-YQ | 10 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 641.7 | 707.8 |
| WNS 12-1.0/1.25/1.6/2.0-YQ | 12 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 768.9 | 849.3 |
| WNS 15-1.0/1.25/1.6/2.0-YQ | 15 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 960.1 | 1061.7 |
| WNS 20-1.0/1.25/1.6/2.0-YQ | 20 | 0.4 to 2.5 (4-25 in bar) | 130~226 | 20/105 | 1276.2 | 1415.8 |
| Note: 1. Custom boiler design provided. 2. Specifications are subject to change without prior notice due to technical improvements. | ||||||
| Model |
Rated heating capacity (mw) |
Rated working pressure (Mpa) |
Output water temperature (℃) |
Return water temperature (℃) |
Fuel consumption | |
| Light diesel oil(kg/h) | Natural gas(Nm3/h) | |||||
| WNS 0.35 | 0.35mw | Atmospheric pressure/0.7/1.0/1.25/1.6 | 85~130 ℃ | 70/60 ℃ | 31.6 | 36.6 |
| WNS 0.7 | 0.7mw | Atmospheric pressure/0.7/1.0/1.25/1.6 | 85~130 ℃ | 70/60 ℃ | 60.4 | 69.3 |
| WNS 1.4 | 1.4mw | Atmospheric pressure/0.7/1.0/1.25/1.6 | 85~130 ℃ | 70/60 ℃ | 122.8 | 146.1 |
| WNS 2.1 | 2.1mw | Atmospheric pressure/0.7/1.0/1.25/1.6 | 85~130 ℃ | 70/60 ℃ | 192.3 | 227.1 |
| WNS 2.8 | 2.8mw | Atmospheric pressure/0.7/1.0/1.25/1.6 | 85~130 ℃ | 70/60 ℃ | 246.1 | 286.5 |
| WNS 4.2 | 4.2mw | Atmospheric pressure/0.7/1.0/1.25/1.6 | 85~130 ℃ | 70/60 ℃ | 367.1 | 412.6 |
| WNS 5.6 | 5.6mw | Atmospheric pressure/0.7/1.0/1.25/1.6 | 85~130 ℃ | 70/60 ℃ | 490.2 | 543.7 |
| WNS 7.0 | 7.0mw | Atmospheric pressure/0.7/1.0/1.25/1.6 | 85~130 ℃ | 70/60 ℃ | 593.6 | 660.7 |
| WNS 10.5 | 10.5mw | Atmospheric pressure/0.7/1.0/1.25/1.6 | 85~130 ℃ | 70/60 ℃ | 936.5 | 998.8 |
| WNS 14 | 14mw | Atmospheric pressure/0.7/1.0/1.25/1.6 | 85~130 ℃ | 70/60 ℃ | 1200.8 | 1330.7 |
| Note: for place limited, we didn't list all models, if you need other capacity, pressure, fuel, please send us inquiry directly, we will send you detailed parameter. | ||||||
Other Boiler Options
Skid-mounted Mobile Boiler
Modular integrated gas oil fired boiler systems. Boiler and all auxiliary are tightly mounted on a skid, allows fast on site installation in just four steps connecting power water steam lines and final finishing.
LHS Vertical Fire Tube Boiler
Capacity from 500kg to 2000kg, 350-1400kw. Vertical fire tube structure, gas or oil fuel powered, small footprint, low cost. Fully automatic control with multiple safety interlocks
LSS Vertical Water Tube Boiler
Capacity from 100kg to 500kg, 60-350kw. Vertical water tube structure, intergrated boiler, fast heating. Suitable for small scale factory.
About Us
■ Founded in 1956, a premium supplier assessed, certified, and inspected by TUV BUV SGS.
■ Leading industrial boiler manufacturer & seller in China.
■ Professional team integrating R&D, production, sales, and service.
■ Holds international boiler certifications: CE, ASME, DOSH, EAC, GOST, ISO
■ Over 20 years of export experience, gold-level certified supplier, ensuring payment and delivery.
■ 53,053㎡ Factory area, supporting video/VR factory audits or third-party inspections.
■ Engineer installation and commissioning services extend to over 60 countries worldwide.
■ Products sold to over 130 countries/regions, covering food, beverage, textiles, paper, wood industries. Serving over 100,000 customers.
Pre-sale Service:
1. Design一We help customer to choose the best boiler model according to the different requirements of different industries.
2. Drawing and files一Supply quality certificates, factory-inspect, fuel consumption calculation, cost analysis, foundation drawings, layout drawings, boiler room drawings nased on your needs, etc.
3. Technical Solution一Design completed boiler system with accessories and installation materials for your company.
4. Transportation一We have shipping partners and forwarder for lowest price and safe.
After-sale Service:
1. Provide a full range of boiler and original spare parts.
2. Overseas engineers installation and commissioning service is available.
3. Training in site, to ensure safe operation.
4. 24 hours online, quick respond.
5. Free maintenance and repair for one year and lifetime service.
If you require any boiler information or price, please feel free to let us know—no obligation.

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