Stainless Steel Centrifugal Fire Pump

I. Product Overview

Stainless steel centrifugal fire pumps are designed based on the centrifugal force transportation principle, using austenitic stainless steel (such as 304, 316) or duplex stainless steel. They provide stable high-pressure water flow for fire water supply systems, building fire hydrants, and industrial fire protection scenarios. The stainless steel material system, combined with precision casting technology, integrates excellent corrosion resistance, high strength, and impact resistance, enabling stable operation in fire water with impurities, seawater fire systems, and high-temperature fire sites to meet the strict reliability and safety requirements of the fire protection field.

II. Core Materials and Characteristics

1.Austenitic Stainless Steel (304/304L)

Characteristics: Contains 18% chromium and 8% nickel, with tensile strength ≥520MPa and compressive strength ≥205MPa. Its corrosion resistance is superior to cast iron (corrosion rate <0.01mm/year in fire water with pH6-8), and it has good weldability, but is prone to stress corrosion in media with chloride ions (Cl⁻ >200ppm).

Applications: Suitable for manufacturing conventional fire components such as pump bodies and impellers, commonly used in building indoor fire protection systems and municipal fire hydrant water supply (water temperature ≤60℃).

2.Austenitic Stainless Steel (316/316L)

Characteristics: Added with molybdenum (2-3%), chloride ion corrosion resistance is 5-8 times higher than 304, tensile strength ≥520MPa, can operate stably in seawater fire systems (Cl⁻ concentration ≈20000ppm), and has outstanding high-temperature resistance (strength decline <5% at ≤200℃).

Applications: Used in fire pumps for coastal buildings and chemical enterprise fire protection systems, resisting corrosion from acid and alkali fire-fighting agents (such as foam extinguishing agents with pH4-10).

3.Duplex Stainless Steel (2205)

Characteristics: Ferritic-austenitic duplex structure, tensile strength ≥620MPa, yield strength 40% higher than 316 stainless steel, impact toughness increased by 30%, pitting corrosion resistance index (PREN) ≥32, and can resist cavitation damage in high-pressure fire water (bubble collapse impact strength ≤300MPa).

Applications: Suitable for high-pressure fire protection scenarios (working pressure ≥1.6MPa), such as fire booster pumps for high-rise buildings and fixed fire protection systems in industrial storage areas.

III. Technical Advantages

1. Excellent Corrosion Resistance and Environmental Adaptability

The corrosion rate of 316 stainless steel impellers in fire water with chloride ions is only 0.005mm/year, with a service life 10 times longer than gray cast iron impellers (cast iron has a service life <2 years when Cl⁻ >500ppm)

Duplex stainless steel pump bodies maintain structural stability at 200℃ high-temperature fire sites, with thermal deformation rate <0.2%, avoiding pump body leakage caused by sudden temperature increases.

2. High-Pressure Water Transportation Efficiency and Reliability

The hydraulic efficiency of duplex stainless steel impellers under 1.6MPa pressure reaches 88%-92%, 15%-20% higher than cast iron pumps, and pressure pulsation ≤±0.1MPa, ensuring stable fire hose jet (range deviation ≤5%).

The matching accuracy between the stainless steel pump shaft and mechanical seal reaches 0.01-0.03mm, with leakage ≤10 drops/minute, meeting the "zero leakage" emergency requirements of fire protection systems.

3. Low Maintenance and Long Life

The passivation film on the stainless steel surface has strong self-healing ability, requiring no additional coating protection, with maintenance costs 60% lower than cast iron fire pumps (cast iron requires regular anti-rust paint spraying, increasing costs by 20%-30%).

316 stainless steel pumps can have a service life of more than 20 years in conventional fire protection systems, 2.5 times longer than cast iron pumps (5-8 years), reducing equipment failure risks in emergency scenarios.

IV. Application Scenarios

1. Building Fire Protection Systems

Suitable for fire hydrant water supply in high-rise buildings and automatic sprinkler systems. 316 stainless steel pumps can resist long-term corrosion from water in fire tanks (water replacement cycle ≥6 months), such as fire booster pumps for office buildings above 30 floors.

2. Industrial Fire Protection Field

Used for fixed fire protection facilities in petrochemical enterprises and oil depots. Duplex stainless steel pumps can transport foam extinguishing agents under high pressure (≤2.5MPa), resisting corrosion from surfactants in the agents (such as fluorine-containing surfactant-resistant foam).

3. Fire Protection in Special Environments

316 stainless steel pumps are used in fire protection systems in coastal areas or ships to resist seawater corrosion (Cl⁻ concentration 20000ppm), such as fire boats in port terminals and fire pump groups on offshore platforms.

V. Precautions

1. Working Condition Limitations

304 stainless steel pumps are unsuitable for fire water with chloride ions >500ppm (such as seawater); 316 or duplex stainless steel materials must be selected, otherwise stress corrosion cracking is prone to occur (cracking probability increases by 15% per 1000ppm of Cl⁻ concentration).

When the working pressure of duplex stainless steel pumps >1.6MPa, the water temperature should be controlled ≤120℃ to avoid grain coarsening caused by high pressure and temperature (strength decline >10%).

2. Maintenance Recommendations

Regularly inspect impeller wear; replace when blade thickness wear >1mm to avoid insufficient fire water volume due to hydraulic efficiency decline (allowable flow deviation ≤8%).

Drain the water in the pump before long-term shutdown to prevent scale formation on the stainless steel surface (especially 304 material is prone to calcium carbonate deposition in hard water).

3. Cost and Energy Efficiency

The procurement cost of stainless steel fire pumps is 2-3 times higher than cast iron pumps (e.g., the cost of SSFP-150 type is about 2.8 times that of the same specification cast iron pump), but the full life cycle cost is reduced by 40% due to low maintenance costs.

With 8-12% higher hydraulic efficiency, it saves about 12,000 kWh of electricity annually in large fire protection systems (such as flow ≥50L/s), meeting the energy-saving needs under the "dual-carbon" policy.