AS-C240 to replace Cartex Fsp single cartridge mechanical seal

Background Knowledge:
Development trends of mechanical seal technology
1. For contact type mechanical seals：reduced leakage, reduced wear, improved reliability and working stability, and prolongd service life are all objectives. 
2. For non-contact type mechanical seals：reduced  leakage, improved fluid film stiffness and working stability, and prolongd service life are targets.