Monolithic isolation joints

ALFA Isolation Joints serve as a positive leak proof, long lasting block against the flow of electric current in all piping systems. When you put ALFA Isolation Joints into service, you bury maintenance costs forever.

International codes as the NEW ISO 15589-1 highly recommend the use of Monolithic Isolation Joints in order to effectively segment and protect the pipelines from corrosion.
NACE also indicates as “Strongly Suggested” the use of monolithic isolation joints for an effective CP System protection.

Factory assembled

ALFA Monolithic Isolation Joints are boltless and completely factory assembled in accordance with the appropriate requirements of ASTM, API, DIN and BS codes.  All welds are butt weld construction.


All Alfa Engineering products are warranted against failure caused by manufacturing defects for a period of 1 year. Any product found to be so defective and returned to us within one year from date of shipment will be replaced without charge.

Made in italy

Each Monolithic Isolation Joint is designed and manufactured at our plants in Modena (Italy) that has a registeredISO 9001:2015 Quality Management System.

Copy of current ISO 9001:2015 certificate is available upon request.

Detailed features

For system operators and engineers

1 – ALFA Insulation Joints serve as a positive leak proof, long lasting block against the flow of electric currents in all piping systems, causing corrosion and leakeges.

2 – Eliminate Short Circuits: Bolt, Sleeves and Washers are the major cause of short circuits in most isolation assemblies are eliminated when using ALFA Monolithic Isolation Joints.

3 – Eliminates costly and time consuming field assembly: ALFA are completly factory assembled and tested. There are no flanges, gaskets, nuts, bolts, sleeves, or washers to handle and consequentially no fluid leaks due to improper field assembly.

4 – There is no possibility, as it happens where gaskets are used in flanges, of water infiltration and consequentially loss of insulating capabilities.

5 – ALFA can be purchased for less then the cost of componets parts of insulated flange assemblies in most pipe sizes.

6 – You can install ALFA for much less then the labor costs of installing an isulated flange assembly.

Monolithic isolation joints vs flanges



1 –  Pre-Assembled and Pre-Tested

2 –  Saving on skilled on-site labour

3 –  No maintanance required

4 – No Failure caused by improper installation

5 – No Pipeline shutdown because of failure, replacemnt or leakage

6 – Simplified serviceability and maintanace

7 – Increases the safety of the pipeline

8 – Increases the life duration of the pipelines

9 – Drastically decreases the OVERALL project LIFE CYCLE COSTS

10 – Historically Longher lead time. Now solved by ALFA and it’s supplier network


1 – Less expensive at the beginning

2 – Has to be assebled on field

3 – Requires skilled knowledge to be installed

4 – It easily breaks during Installation

5 – Failure may cause plant shout down and expensive leakages

6 – Does not grant the same level of electrical insulation as Monolithics Insulation Joints

7 – Water can sometime go thrue the gasket isolation

8 – Reparing a demaged or leaking Kit exceeds by far the initial cost of a Monolithic Insulation Joint

Why to use joints?

Testing, qualifies, welding, corrosion

Corrosion destroys approximately 30% of the world’s annual production of steel. Where you find pipelines for gas an oil distribution system, you will also find a range of Alfa Engineering isolation joints. The correct location of a monolithic isolation joint results in saving overall cost of corrosion control systems.


 For onshore projects, an isolation joint is used to limit the spread and hence cost of cathodic protection current to those pipes that need to be effectively and economically protected by the main CP system.

 An isolation joint is used to electrically “split up” long pipelines into distinctive system. Or to isolate and ensure that CP or stray electricity currents do not cause increased corrosion.

 Or to provide protection against earthing currents at domestic and industrial premises where the PME (Protection Multiple Earthing) system is in use.

The correct location of a Monolithic Isolation Joint results in saving overall cost of corrosion control systems.
Monolithic Isolation Joints are to be installed:
                                                                                          ● Between pipeline sections of different metallic materia
                                                                                          ● At pipeline DN variation
                                                                                          ● When pipeline enter/exits ground level
                                                                                          ● When pipeline passes from On-Shore to Off-Shore
                                                                                          ● Beginning and end of CP Systems