Carbon Graphite Seal Rings

Four are standard: silicon carbide (SiC) is the general-purpose choice with high hardness and conductivity and good resistance to particle erosion; tungsten carbide (WC) is tougher and suits vibration and shock; alumina ceramic is the low-cost option for mild media and low speed; high-chrome stainless is reserved for light, slow duty. Tell us the mating material and coating and we select the carbon graphite grade around it.

Start with temperature and media. Resin impregnation (M106K) seals the pores for food and pharma oil-free duty at about 220°C continuous; furan-impregnated material has Tg 260-300°C, Td5 340°C and 65% char yield at 700°C, making it the upgrade where dry starts are credible; antimony impregnation (M106D) is rated 500°C and only oxidises noticeably at 600-650°C, used for refining hot oil pumps; carbonized (M191T) reaches 600°C with the highest chemical inertness.

Four. (1) Thermal: dry running pushes PV past the 0.8-1.2 MPa·m/s limit, the face crosses resin Tg, friction jumps from 0.08 to 0.22 and the impregnation layer shears off the matrix. (2) Abrasive wear: above 50 mg/L solids in the media, life drops 60-80%, showing as even bore enlargement and surface roughening — a magnetic filter restores life to over 85% of original. (3) Thermal cracking: rapid temperature change puts radial cracks in the face and it leaks. (4) Chemical attack: the wrong resin type is swollen or eaten by the media. The first two dominate real field failures and both trace back to lost liquid film or dirty media.

Yes. Drawings and physical samples are both accepted, including non-standard dimensions, grooving, drilling, chamfering and face lapping, machined on CNC to micron-level tolerance. Standard stocked items ship directly; non-standard parts are quoted by quantity and complexity. If you only have a sample, we measure it and send back a drawing for your approval first.