The unitary insulation joint (directly buried and without maintenance) is use of O&U type self-tightening seal, to sealed the laminated section of insulating ring. It’s completely avoid the moisture of water pressure test and soil infiltration insulation joint internal. Especially we adopt the king of rubber (fluorine rubber) seal, It makes anti-aging degree strengthening, also use life and pipeline life equate.

Rigid insulation joint formed a rigid cylinder that far greater than pipeline bending section coefficient. Cause it can bear larger bending moment (According to the same strength to pipeline   design), eliminate the other insulation joint for structure is not rational caused by insufficient stiffness caused by leakage accident.

The insulation ring of rigid insulation joint is made of high compression strength (not less than350N/mm2), low water absorption, high electrical insulating strength, anti-aging materials. Insulation resistance value is more than 10 m Ω. Because of it is far greater than other insulation joint resistance, greatly improving the insulation and to reduce the leakage current. Another sleeve (assembly) is annular space. It is inject polymer composite material, low viscosity, cold solid heat hard resin, and has certain compression strength, more can give full play to the cathode protection, improve the protected the pipeline operation life.