Special mechanical seals are here described as the mechanical seals which are special for us and the special mechanical seals include all types of mechanical seals:O-ring mechanical seals,metal bellow seals,cartridge seals,PTFE bellow mechanical seals,PTFE wedge mechanical seals,rubber elasmoter mechanical seal,single spring mechanical seals, mutiple spring mechanical seals,automotive pump seals and etc. Self-production of mechanical seals can ensure quality mechanical seals. Tight conrol of all the mechanical seal parts are carried out from the raw materials incoming,some mechanical seal parts incoming. All the mechanical seal faces or rings are self-produced accoring to ISO9001-2015 quality systems.