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.

The Problem

THE
PROBLEM

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

THE
SOLUTION

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.

THE
BENEFITS

Unique Innovation

Cross-Directional Flow (CDF)

The diamond-shaped pattern promotes drainage regardless of pipe orientation. Unlike cross-crimped jacketing, the channels allow water to flow both vertically and horizontally, helping to prevent pooling.
CUI Prevention

Designed for Drainage

When a location for water to exit the system, such as a weep hole or drainage port, is provided, JM’s Cross-Flo Jacketing reduces the risk of CUI because the channels between the insulation and the jacketing allow water to flow toward the exit point.
Additional Protection Layer

3-Mil Polyfim Moisture Barrier

Cross-Flo Jacketing has a bare outer surface and comes standard with a 3-mil thick polyfilm moisture barrier heat-laminated to the interior surface to provide additional protection against corrosion of the jacketing and the underlying metal pipe, vessel or equipment.
Easy to Install

Handles like Standard Aluminum

Cuts, curls, and handles like other embossed patterns with minimal change to installed thickness at small, medium, and large sizes.
Longer Lifespan

Extends the life of an insulation system

In conjunction with weep holes or drainage ports, Cross-Flo Jacketing can allow more water to escape an insulation system, as compared to other jacketing, so the system is better protected against CUI, plus associated costly repairs and maintenance.

THE
TESTING RESULTS

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.

INSTALLATION TIME TRIAL
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.

REQUEST A SAMPLE

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

EXPLORE MORE
RESOURCES

Frequently Asked Questions Documents Videos Additional Applications

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Why is Cross-Flo jacketing better than other jacketing patterns?

Stucco-embossed patterns are not deep enough to allow for effective water drainage.
Unlike cross-crimped jacketing, CDF promotes drainage almost equally well in any installed direction. Cross-crimped jacketing drains quickly when the open space between the jacketing and the insulation is oriented vertically, but halts water drainage when oriented horizontally.

Does Cross-Flo jacketing require any changes to overall system design?

In systems at risk of CUI, JM strongly recommends that Cross-Flo jacketing is installed in conjunction with weep holes, to provide anegress point for moisture. JM’s internal testing was completed with ¾” circular weep holes; specific system configurations should be designed by a qualified engineer.

Why are hydrophobic or water-repellent insulations alone insufficient to protect against CUI?

Although hydrophobic materials themselves repel water, all insulation types have seams, and water may ingress through system damage over time. Additionally, water-repellent treatments may be susceptible to degradation over time, due to burn-off or other factors. Regardless of the type of insulation used, the longer water is allowed to remain in the system, the higher the likelihood it will reach the metal surface of the pipe and result in CUI.