I. The rotating ring must be "durable", and the stationary ring must be "corrosion-resistant"  

The rotating ring rotates together with the shaft; it must be wear-resistant, high-temperature resistant, and able to axially micro-move to compensate for wear. The stationary ring is fixed on the gland and does not rotate; it requires good sealing, buffering ability, and corrosion resistance. The general principle of selection is hard-soft pairing — the rotating ring is harder, the stationary ring is softer (e.g., silicon carbide paired with graphite). Only under extreme working conditions is hard-hard pairing (dual silicon carbide) used. Otherwise, either the sealing faces will wear out quickly, or they will directly seize and burn.  

- Bonve Pump Cam-Type Double Rotor Pump -  

II. There are only a few common materials; remember their characteristics  

Silicon Carbide (SiC): High hardness, good thermal conductivity, acid and alkali resistant (not resistant to hydrofluoric acid), temperature resistant up to 400°C. It can be used in medium to high pressure and with slight particles. It is an "all-round" material.  

Cemented Carbide (YG6/YG8): Extremely strong resistance to particle erosion, suitable for slurry pumps and Slag slurry pumps, but afraid of strong acids.  

Carbon Graphite: Good self-lubricating property, low friction coefficient, but poor hardness. It is only used as a stationary ring for clean, low-pressure conditions.  

Alumina Ceramic: Corrosion-resistant and low cost, but brittle, afraid of impact, and cannot be used in particle-containing media.  

III. Directly copy the pairing schemes for different working conditions  

Clean water, normal temperature circulating water: Preferred: Silicon Carbide vs Silicon Carbide, hard-hard combination is wear-resistant and worry-free; Secondary: Silicon Carbide vs Graphite, slightly lower cost.  

Particle-containing media (mud slurry, ore slurry, ash water): Preferred: Cemented Carbide vs Graphite. The cemented carbide withstands particle erosion, and the graphite's self-lubrication reduces wear. Note: Dual silicon carbide is prone to brittle fracture under strong particles — never use it. If you are using a Bonve rotary pump to transport sand-containing or ore slurry, this combination is particularly reliable.  

High-temperature conditions (heat transfer oil, steam, high-temperature chemical materials): Preferred: Silicon Carbide vs Silicon Carbide. Silicon carbide withstands temperatures over 800°C and has good thermal stability; Secondary: Silicon Carbide vs Graphite, but graphite can only be used up to about 600°C.  

Highly corrosive media (concentrated sulfuric acid, caustic soda, organic solvents): Preferred: Silicon Carbide vs Silicon Carbide. Silicon carbide is extremely chemically stable and hardly reacts with strong acids or alkalis; Secondary: Silicon Carbide vs Impregnated Graphite. Ordinary cemented carbide will be corroded — directly prohibited.  

Low-temperature conditions (LNG, liquid nitrogen): Still Silicon Carbide vs Silicon Carbide, good toughness at low temperatures, not prone to brittle fracture.  

Easily vaporized media (liquefied gas, light hydrocarbons): Choose Silicon Carbide vs Graphite. The self-lubrication of graphite can handle instantaneous dry friction and avoid seal burning.  

-Bonve Pump Industry Mechanical Seal-

IV. Pay special attention to these mistakes  

Graphite paired with graphite: Both are soft; friction generates heat and they will burn immediately.  

Silicon carbide paired with ordinary cemented carbide: The hardness difference is too large; the cemented carbide will be ground into powder.  

Cemented carbide paired with cemented carbide: Poor toughness; it will shatter under impact.  

Ordinary ceramic used in strong impact conditions: It will explode under pressure, and the fragments may even damage the equipment!

Bonve pump always adheres to the philosophy of "Wholeheartedly Making Good Rotor Pumps," committed to providing global customers with customized conveying and mixing solutions. If you have technical inquiries, selection needs, case references, or other cooperation intentions related to Bonve rotor pumps, please feel free to contact us.  

Service Hotline: 0574-87588986 13586591794  

Official Website: www.bvpumps.com  

Business Email: market@bonvepumps.com  

We look forward to working with you to drive efficiency and innovation in industrial fluid transmission with precision technology.