Insulating flange kits versus monolithic isolating joints
It is no secret that the effectiveness of your cathodic protection system depends on the experience of the installer and the quality of raw materials put into the pipeline. Many CP professionals often wonder about the pros and cons of using insulating flange kits over monolithic isolation joints.
The monolithic insulating joint was developed as an alternative to insulating flange kits. It has been widely used in Middle Eastern and European countries in the Oil & Gas Industry. While they have been used in the United States, their benefits have been overshadowed by long lead times from European manufacturers.
Now with the expansion of a United States insulating joint manufacturer, I wonder if the use of insulating joints will give insulating flange kits a run for its money.
What are the pros and cons of using monolithic insulating joints versus insulating flange kits?
Disadvantages of insultating joints
The primary disadvantage of using monolithic insulating joints in U.S. pipelines has been the long lead times from European manufacturers. While some U.S. distributors have tried to appease the availability issue it has become a challenge for contractors to work with staggering lead times when inventory has been depleted.
The often perceived secondary disadvantage is the upfront expense of an insulating joint which can be twice the cost of an insulating flange kit.
Advantages of Monollithic Isolation
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| Barlow Insulating Joints ~ Now offering stock availability in most sizes |
Insulating joints come preassembled and pretested versus the traditional insulating flange kit, which requires a skilled technician to assemble it on site. By using the Insulating joint the company saves on site labor. The joints are also less likely to fail from improper installation which could render a CP system ineffective and likely result in both internal and external corrosion.
With an insulating joint, serviceability and maintenance is simplified. Whereas, when using an insulating flange kit the system may become shorted when buried (from settling, thermal expansion or over-tightening). In this case, the cost to repair a damaged or leaking system significantly exceeds the initial investment of an insulating joint. It is also more likely that the pipeline would have to be shut down if maintenance or replacement is required.
When evaluating the advantages and disadvantages of using insulated flange kits versus monolithic insulating joints it would seem that when life cycle costs are considered, the use of monolithic insulting joints is advantageous over the flange kits.
New U.S. Insulating Joint Manufacturer
With the recent rash of gas pipeline explosions, of which many believe are corrosion-related, the spotlight is on gas pipelines to increase safety and quality of pipeline materials and testing. The expansion of Barlow Insulating Joints, a U.S. manufacturer seems timely. Barlow apparently is not new to the industry, and has manufactured insulating joints for over 50 years serving the east coast. The company was acquired by IMAC Systems a couple years back who has decided to expand the Barlow line to the west coast.
Perhaps the availability of U.S. monolithic insulating joints will impact the way U.S. pipelines choose their insulating methods.
pipeline becomes passive or cathodic. The science reveals that as long as the electron current is arriving at the cathode (pipeline) faster than oxygen is, then corrosion will be prevented or significantly slowed.
