The Pipeline Insulating Joint (PIJ) is a high-resistance fitting used to electrically isolate sections of a pipeline to improve the effectiveness of cathodic protection systems and to reduce ground-loop currents. The PIJ is provided with extension nipples that match the pipeline wall and grade and are long enough to eliminate any possibility of thermal damage to the PIJ during field welding. It overcomes the problems of flange and flange kits with small rigidity, easily leak, unable to be buried under ground, short service life, etc. The insulating joints have realized the function of maintenance-free after buried under ground.
The monolithic design of the PIJ results in a pipe fitting having high cyclic bending strength integrity. The integrity of the PIJ is further enhanced by using rubber fluoride seals and insulation of high-pressure, glass-filled, structural epoxy laminate. The monolithic profile will not trap moisture and reduces the possibility of crevice corrosion. This is an additional advantage of the monolithic design over conventional insulating flanges.
Design Specifications
Pipe Insulating Joints are designed in accordance with ASME Pressure Vessel Code, Section VIII, Division 1, unless another recognized code is specified. Each PIJ is designed to be at least as strong as a comparably rated pipeline when subjected to external loads.
Technical parameters:
Size:DN50 to DN2500
Pressure range: PN1.0 to PN42 Maps
Service life: same as the service life of pipeline
Applicable flows: oil, gas, water, chemical raw material, ore pulp
Quality requirement:
Insulating resistance>10 MΩ at DC 1000V
Insulating intensity: no breakdown or puckering arc for one minute at 2500V 50Hz
Hydraulic test pressure: 1.5 times of designed pressure
Air-tight testing pressure: equivalent to designed pressure
Non-destructive testing: all the welding seams are 100% X ray-detected, All the butt-welding ends are 100% magnetic power detected
Bevel end: according to ASME B16.25
Materials characteristics:
Assemblies: forging piece
Extension nipples: equivalent to the material of pipeline
Insulating material: high-pressure, glass-filled, structural epoxy laminate
Filling material: high strength epoxy resin
Sealing material: rubber fluoride 26
Anti-corrosion insulating material coating: Two component solvent free epoxy coatings or anti-corrosion heat shrink sleeve
Test items:
Hydrostatic testing : 1.5 times of design pressure
Voltage testing : AC 3000V
Insulating resistance: DC 1000V
Visual inspection
Dimensional inspection
Hydraulic Test and Bending test
Hydraulic cycling (fatigue) testing
Dielectric strength test: Immersed in electrolyte solution
Coating adhesion test
Ordering Information
Please provide the following information on any purchase order or request for quotation:
1. Nominal pipe size
2. Pipe wall thickness
3. Pipe grade
4. Design rating or pipeline pressure
5. Pipeline contests
6. Design Temperature
Provide other information as much as possible
