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Insulating Joint
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Namdaran Petrogas Industries Insulating Joint (NIJ) 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. Unlike insulating flanges or flange kits that are field assembled and tested, the NIJ is factory assembled, electrically tested at different stages of manufacturing, and hydrostatically tested. The NIJ 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 NIJ during field welding.

Monolithic Insulation Joint

Are boltless, rigid pipeline components, factory-welded and ready for installation, A design which has proven successful throughout the world even for highest requirements Maintenance-free Suitable for underground installation without the need for special precautions or for above ground installation absolutely no impairment due to external influences

Mechanical Properties

The excellent mechanical properties are achieved by a rigid design of statically favourable form, using thermo-setting plastics free from cold flow as insulating materials. The welded unit provides a safe and reliable connection even over extremely long period of operation without the risk of the secured and locked unit loosening or separating. Countless tests, prototype tests and empirical data gained during the course of many years of practical operation confirm the soundness and correctness of the complete welded design.

Electrical Properties

The dimensioning and practical arrangement of the insulating sections within the overall design in addition to technical production factors, in conjunction with insulation materials of a suitable quality, result in the ideal overall electrical behavior of the insulating joints large external insulating length, thus eliminating the possibility of spark over Very good dielectric strength, substantially greater than is the case with conventional insulating flanges. A decisive factor in safe operating behavior, however, is linearity between the voltage applied and the resistive leakage current.


In accordance with standards such as ASME, DIN 2470, TRBF and other international standards, or in accordance with IPS / IGS specific requirements. If no other regulations specified, the IPS or IGS specification are valid. Additional forces such as bending moments and tensile forces etc. must be specified by the customer. Basically, all components of forces and force values occurring can be taken into consideration during design calculation. All mechanical analysis will be done by ANSYS Software and will be interpreted acc. To ASME VII Div. I / II standard.


Suitable for flow media such as natural gas, crude oil, kerosene, gasoline, propane, butane, coal gas, ethylene, nitrogen and drinking water etc.
Media such as sour gas and oxygen necessitate special materials and design bases Standard versions up to maximum +80 °C constant temperature. Special versions for district heating pipelines up to +150 °C


Pipe materials used are in accordance with API, ASTM/ASME or DIN standards. Seamless rings made of plate material or of forged quality, depending upon costumers requirements and design calculations Seals materials are selected as e.g. FKM(Viton), NBR, EPDM and other materials according to ASTM D 2000 Insulating materials are supplied according to ASTM D709 standard.

External Coating

We apply two layers Epoxy Zink Rich as primer, and two layers Polyurethane as top coat as our standard.
Other types of coating are possible according to agreement and purpose such as Bitumen primer, coal tar epoxy resin and others.

Internal Lining

As per our standard without lining Electrically conductive media and deposits require an appropriate internal lining Virtually all types of lining can be applied upon agreement.

Test / Inspections

According to the agreed requirements, usually: a. A strength and tightness test with water
b. An electrical breakdown test with 3000 V/1 minute, AC, 50 Hz (both before and after the hydrostatic pressure test as our standard)
c. An electrical resistance test, standard 1000 V DC
d. Checking the material certificates
e. Evaluation of the destructive and non destructive tests
f. Dimensional checks
Depending upon the basis of the order, the tests are conducted either by our quality assurance department, by the customer himself or by an authorized third party

Ordering Information

Please provide the following information on any purchase order or request for quotation:
1. Design code
2. Nominal pipe size
3. Design pressure
4. Design factor
5. Working temperature
6. Pipeline wall thickness or bore
7. Pipeline grade
8. Fluid conveyed
9. Electrical Resistance test (MΩ @ 1000V DC)
10. Dielectric test @ 5000 V or 3000 V
11. Design factor
12. Quantity

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