Water isn’t welcome inside an insulation system, so get it out – and fast – with the help of Johns Manville’s Cross-Flo Jacketing. This new product is perfect for industrial and mechanical insulation systems, helping to expel unwanted water.

Cross-Flo is a protective metal jacketing system with an embossed pattern designed to promote cross-directional flow. This provides a path for liquid that may enter the insulation system to reach the low point and exit the jacketing through a weep hole or drainage port.

In fact, in testing, Cross-Flo Jacketing drained 80% faster than smooth metal jacketing after one hour! There are so many opportunities to use Cross-Flo. It is recommended for indoor or outdoor applications up to 8 feet in diameter, and can be used on all pipe as well as vertical and horizontal tanks.



Corrosion Under Insulation (CUI)

CUI is a huge concern for engineers and specifiers in the industrial sector. Despite insulation systems being designed to deter water ingress, infiltration is almost inevitable. Even though JM’s industrial products are water resistant or hydrophobic (and the rigid insulations also have a corrosion inhibitor), impurities present in water can interact with metal piping and lead to corrosion. CUI is difficult to detect, which can lead to catastrophic consequences.

When does CUI occur? 
•  During construction and temporary shutdowns
•  Through improper installation or damage during normal operation
•  With exposure to water from rain, storms or improper storage

What's the Impact?
•  Refineries can face lengthy downtimes
•  Costly repairs



Cross-Flo® Jacketing
*Patent pending

Cross-Flo® Jacketing is a unique innovation developed by JM for ambient and hot systems. It has an embossed pattern engineered to promote cross-directional flow (CDF), thereby providing a path for liquid that may enter the insulation system to reach the low point and exit the jacketing through a weep hole or drainage port.

Although insulation systems are designed to deter water ingress, there are many ways by which water may enter a system undetected, which may lead to corrosion under insulation (CUI). Cross-Flo Jacketing reduces the risk of CUI by minimizing the time water remains in the system.

Weep holes allow any moisture trapped between the pipe and the metal jacketing to escape.  JM recommends the use of a weep hole or drainage port in conjunction with Cross-Flo Jacketing to maximize efficacy and reduce the risk of CUI.



To test the efficacy of Cross-Flo Jacketing, JM’s team conducted a small-scale simulation testing during which 100mL of water was allowed to drain through representative insulated pipe sections jacketed with Cross-Flo, smooth, and stucco embossed patterns. Tested insulation types included calcium silicate, perlite, mineral wool, and aerogel.

Cross-Flo significantly improved the drainage rate compared to smooth and stucco embossed, regardless of insulation choice. These results emphasize the design flexibility available when choosing Cross-Flo Jacketing for CUI protection.


Cross-Flo® Jacketing vs. Smooth Aluminum Jacketing

Cross-Flo® Jacketing is a great way to fight corrosion under insulation. If you’re wondering how it stacks up when it comes to installation time, watch for yourself in this time trial video. We compare Cross-Flo and smooth aluminum jacketing side-by-side.


Fill out the form to request a sample of Cross-Flo Jacketing.



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Read all FAQ's here

Insulation Intel® Infographic: An Overview of the Mechanism and Longevity of the XOX Corrosion Inhibitor® 

Technical Bulletin: Cross-Flo Jacketing

Technical Bulletin: Metal Corrosion Under Thermal Insulation

Technical Bulletin: Stress Corrosion Cracking of Stainless Steel

Technical Bulletin: Insulation Coating Vs. Traditional Insulation

Polyfilm Moisture Barrier (PFMB) Data Sheet

Polyfilm Moisture Barrier (PFMB) Fact Sheet

Cross-Flo Jacketing Hammer Drop

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XSPECT ISOfoam APF Board and Cross-Flo Jacketing Resource Page

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