High Anti-corrosion Blower, Stainless Steel Blower & Ordinary Blower: Application Scenario Comparison
Many buyers only focus on pressure and flow rate when purchasing Roots blowers, ignoring the corrosive characteristics of gas media. If ordinary cast iron blowers are directly used for gas containing hydrogen sulfide, acid and alkali vapor, pitting corrosion, impeller rust and seizure, increased clearance and severe air leakage will occur within a short period. Some projects need overhaul or replacement in half a year. Ordinary blowers, stainless steel blowers and high anti-corrosion blowers are not simple material upgrades. They differ greatly in corrosion resistance grade, applicable media, procurement cost and maintenance cycle. Below is a full comparison to help you select the correct model at one time.
1. Core Characteristics of Three Types of Blowers
1. Ordinary Cast Iron Roots Blower
Main body adopts HT250 cast iron with conventional anti-rust paint on the surface. It is only suitable for clean and dry air with poor corrosion resistance. It is prone to rust when exposed to moisture, trace acid or alkali gas. Pressure specification: Single-stage boost 9.8~98kPa, two-stage series connection up to 196kPa.
Exclusive practical note rarely found online: The paint of ordinary cast iron blowers is only surface protection. Once the paint film is damaged by water vapor scouring, the cast iron substrate will be directly exposed, and pitting corrosion will spread rapidly inward from the damaged area. Under dry and clean air conditions, the service life of the complete machine can reach 8~12 years; in humid and corrosive environments, rusting and increased internal leakage will occur within 2～6 months.
2. Stainless Steel Roots Blower (304 / 316L)
The wetted parts such as casing and impeller are made of stainless steel. Relying on the passivation film on the stainless steel surface to resist oxidation, weak acid and hydrogen sulfide. 304 suits mild corrosion; 316L contains molybdenum element and has stronger resistance to chloride pitting corrosion, suitable for salt-containing wet biogas and mild chemical waste gas. Limitation: It will still suffer pitting corrosion when exposed to concentrated hydrochloric acid and high chloride ion medium, and is not suitable for strong corrosion working conditions.
3. High Anti-corrosion Roots Blower (Fluorine-lined / 2205 Duplex Steel)
The wetted parts adopt fluorine lining anti-corrosion treatment or 2205 duplex stainless steel, equipped with fluorine rubber seals. It can resist strong acid, high chloride ion and highly corrosive chemical waste gas. It has the highest anti-corrosion grade among the three types, with higher cost, specially for harsh chemical and high-salt wastewater waste gas working conditions.
Standard Specification: The full range of Roots blowers from Mingtian Machinery are manufactured in accordance with JB/T 8941.1-2014 General purpose Roots blowers Part 1: Technical requirements, whose technical indicators are equivalent to ISO/TC117 international blower specifications. Performance test follows JB/T 8941.2-2014. Parameters can be expressed in metric units (kPa, m³/min), and can be converted to imperial units (PSI, CFM) for overseas project review.
2. Application Scenario Comparison Table
| Blower Type | Material | Corrosion Resistance Level | Recommended Application Scenarios | Unsuitable Working Conditions | Buyer’s Core Concerns |
| Ordinary Cast Iron Blower | HT250 cast iron with standard painting | Low | Conventional clean wastewater aeration, freshwater aquaculture oxygenation, pneumatic conveying of clean air, kiln combustion supporting without corrosive gas | Environment with hydrogen sulfide, acid & alkali steam, high salt and chemical waste gas | Low budget, clean medium, stable continuous air supply |
| Stainless Steel Blower (304/316L) | 304 /316L stainless steel wetted parts | Medium | Biogas boosting & recovery, electroplating bath aeration, mildly corrosive wastewater & waste gas, food & pharmaceutical clean air supply, waste water containing trace hydrogen sulfide | Concentrated hydrochloric acid, seawater waste gas with high chloride ions, strong oxidizing acid gas | Balance anti-corrosion performance and cost; medium with mild corrosion; no metal impurities in delivered gas |
| High Anti-corrosion Blower (Fluorine-lined /2205) | Fluorine lining or duplex special alloy, fluorine rubber seal | High | Chemical acid waste gas transportation, high-salt seawater wastewater, strong corrosive VOC, waste gas with high chloride ions, pickling process gas | Dry and clean air (low cost performance, waste of investment) | Strong corrosive medium, long-term stable operation, reduce downtime and maintenance risk |
3. Common Selection Mistakes to Avoid
Mistake 1: Directly select stainless steel blower for slightly humid conditions. For ordinary municipal clean wastewater with low sulfide and chloride ion content, ordinary cast iron blower is sufficient, no need to pay extra cost for stainless steel.
Mistake 2: Stainless steel is universally anti-corrosive. 304 stainless steel will still suffer pitting and perforation under high chloride ion medium. For seawater and high-concentration salt wastewater, stainless steel blower may fail, and special high anti-corrosion material model must be adopted.
Mistake 3: Apply high anti-corrosion blower for clean dry air. High anti-corrosion blower has high purchase price. Using it for clean air conditions will waste investment and increase project cost.
Exclusive practical tip: Material selection for corrosion resistance should not only depend on gas name. Gas temperature, humidity, chloride ion concentration and pH value are four key indicators. For hydrogen sulfide, dry hydrogen sulfide causes slight corrosion to cast iron; once condensed water exists, acidic liquid will be formed quickly and corrode ordinary cast iron blower rapidly.
4. Advantages of Mingtian Machinery (Shangu)
- Three grades of anti-corrosion blowers are fully self-developed and manufactured: ordinary cast iron, 304/316L stainless steel, fluorine-lined /2205 high anti-corrosion Roots blowers. Impellers are precision CNC machined with accurately calibrated dynamic and static clearance. Single-stage boost:9.8~98kPa, two-stage series up to 196kPa.
- Custom sealing solutions available: multiple seals such as nitrile rubber and fluorine rubber, matched according to medium and temperature to prevent medium leakage.
- Professional technical team provides free medium and working condition calculation. Collect gas composition, temperature, humidity, pH value and chloride ion data to accurately match materials, avoiding premature equipment scrapping caused by wrong material selection. Many customers previously chose wrong materials and their blowers rusted within half a year. After switching to our matched anti-corrosion blowers, the equipment service life is greatly extended.
- Every unit passes full-load performance test, fully complying with JB/T 8941.1-2014. English datasheets and imperial unit conversion (PSI, CFM) are available for overseas customers.
- One-stop complete set delivery: supporting silencers, safety valves, filters and pipe fittings; provide installation guidance, operation and maintenance training, fast supply of original spare parts to reduce production downtime.
Contact Information
Reach us directly：
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📞 Phone / WhatsApp: +86 187 6611 7068
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🌐 Official Website: https://www.mtrootsblower.com