• Flame Spread of 5 on both the inside and outside of the duct (ASTM E-84)
  
• Smoke Development of 10 on both the inside and outside of the duct (ASTM E-84)
  
• Halar® veil in the corrosion liner for premium corrosion resistance
  
• Built to long established industry guidelines for corrosion resistant fiberglass composites
  
• Easy to assemble with a variety of joining techniques
  
• Independent 3rd party QA auditing by factory Mutual and U.L.
  
  

	Factory Mutual Approvals- Dual Guard 2000 passed Factory Mutual's new, tougher 4922 test procedure for non-sprinkled fume and smoke removal systems - file No. 4B1A5M.AM. Dual Guard 2000 passed Factory Mutual's new tougher 4910 test procedure for Clean Room Approved Materials - File No. 3006453.
	Underwriters Laboratories Listing- Dual Guard 2000 passed U.L. 181 test procedure, leading to its listing as a Class 1 Duct in accordance with U.L. requirements - File No. MH26567. UL 181 Listing meets the requirements for NFPA

There are many reasons to consider the use of U.L. Listed or FM Approved duct. Key reasons include:

• Building code approval requirements, including those of B.O.C.A., U.B.C./ I.C.B.O. and others, require testing to ASTM E-84 for flame spread and smoke development. If the duct does not exhibit flame spread </= 50 on both the inside and outside of the duct, it must be sprinkled.
  
  
• Dual Guard 2000 has been tested by both Factory Mutual and Underwriters Laboratories. Its flame spread of 5 and smoke development of 10, on both inside and outside of the duct, assures you that a Dual Guard 2000 system will meet building codes and insurance requirements.
  
  
• Insurance carriers may require the use of Factory Mutual Approved or U.L. Listed duct either to maintain insurance coverage or to maintain favorable rates.
  
  
• Factory Mutual Approved systems, when approved for 4922 and 4910 protocols, are less expensive than other options, including the use of standard duct sprinklers.
  
  
• Selecting Factory Mutual Approved, U.L. Listed duct systems provides automatic third party qualification and on-going audits of your supplier’s quality. Insurance underwriters and local building codes routinely require the use of low smoke, fire safe materials in the construction of process facilities. Dual Guard 2000 meets these requirements without the use of either internal or external Sprinklers.
  
  

Until recently, the primary option for meeting flammability requirements on corrosive-fume and smoke handling applications meant using an expensive sprinkler system. Sprinkled duct systems, including standard class 1 flame retardant systems, are typically constructed using corrosion grade polyester, vinyl ester, or furan resin systems, with fiberglass reinforcement.

Use of sprinklers means: 

• The addition of corrodible sprinklers every 12 feet 
• Addition of 4-inch drains every 50 feet and at low points (in case of accidental sprinkler discharge)
• Installation of sprinkler supply mains 
• Installation of sprinkler drain piping to a chemical containment area for treatment
• Additional duct supports-sprinkled duct must, by (U.M.C., NFPA ) code, be designed as if half full of water
• Maintenance and testing requirements for the sprinkler system, including routine replacement of corroded sprinkler heads

Where sprinklers are deemed unacceptable for any of the above reasons, a non-sprinkled vinyl ester/phenolic dual-resin laminate has often been used. Unfortunately, use of the vinyl ester generates hazardous smoke levels well in excess of many building codes. Low smoke polyesters and vinyl ester resins typically have smoke generation numbers between 350 - 900, depending upon the grade of resin.

Code organizations such as B.O.C.A., U.M.C. and the Canadian National Building Code use an ASTM E-84 test procedure to measure flame and smoke generation (also known as NFPA 255, UL 723 or CAN 4-S102). Some of these codes require a flame spread of 25 and a smoke generation of 50 or less on both the inside and outside of the duct, or sprinklers must be used.

Now, using recently developed raw materials, Composites USA has introduced the Dual Guard 2000 duct system that eliminates the need for sprinklers, meets building code concerns for flame and smoke, while also offering an enhanced corrosion resistant product.

Ignition tests, during which samples are exposed to increasing heat flux levels up to 60 kW/m², are used to calculate the thermal response parameter (TRP).

1. Fire propagation tests, in which samples are burned in the presence of 40% oxygen, help generate the fire propagation index (FPI).
   
2. Combustion tests, similar in nature to the fire propagation tests, run at 21% oxygen are used to generate smoke index (SI) numbers.
   

From the above tests, Factory Mutual calculates a Smoke Damage index (SDI) which is the total mass of smoke generated to the total mass of the material loss. The 4910 upper limit for the SDI is 0.04.
FPI values are used for classification of materials as either non-propagating (good) or propagating. The 4910 upper limit for the FPI is 6.0.
CDI, or the corrosion damage index, is a measure of the corrosiveness of by-products of combustion, in the event of a fire. This value is no longer tested or reported by Factory Mutual, except by request. However, Dual Guard 2000 was tested and passed to the original FM test criteria.

Summarizing, the variables, units, and tests values for Dual Guard 2000 FM 4910 testing is as follows:

• FPI - Fire Propagation Index (m/s^1/2)/(kW/m)^2/3 which is a measure of the material's ability to propagate beyond the ignition zone. Dual Guard 2000 value = 1.8.
  
• SDI - Smoke Damage Index (m/s^1/2)(g/g)/(kW/m)^2/3 which is a measure of the smoke contamination expected from a fire. Dual Guard 2000 value = 0.4.
  
• CDI - Corrosion Damage Index ((m/s^1/2)/(kW/m)^2/3)(A/min)/g/m³) which is a measure of limiting the corrosive byproducts produced during a fire. Dual Guard 2000 value = 1.1.
  

The values above are generated using the following:

• CHF - Critical Heat Flux (kW/m²) Dual Guard 2000 value = 35.
  
• TRP - Thermal Response Parameter (kW/m²s-^1/2) Dual Guard 2000 value = 1260.
  
• SI - Smoke Index (yield of smoke, g/g) Dual Guard 2000 value = 0.02
  
• ACI - Average Corrosion Index (average corrosion rate per unit concentration of material vapors. (A/min)/(g/m³) Dual Guard 2000 value = 0.61.
  

With the introduction of FM 4910 Test Protocol, only products passing the requirements for all three of the above test criteria were eligible for FM Approval. Composites USA Dual Guard 2000 was tested to these criteria and passed, with the test results shown above. The requirement for passing the CDI was later discontinued by FM.

Advantages of the Dual Guard resin system include corrosion resistance, high temperature resistance, it does not readily burn, gives off low smoke, and has low smoke toxicity.

Dual Guard is built to the same standards that have guided the fiberglass corrosion industry for over thirty years. These include-

1. Inner Surfacing Layer, reinforced with Halar® surfacing veil, to result in a (25 mil/0.6mm) 0.025 inch-thick reinforced resin-rich surface. Not all FM ducts provide a corrosion veil; none use a premium Halar® veil.
   
2. Interior Layer reinforced with non-continuous glass strands at 20%-30% by weight, having fiber lengths from 0.5-2.0 inches.
   
3. Structural Layer of continuously wound fiberglass to provide optimal strength for a given application. This layer is typically 65% by weight glass.
   
4. External Layer of woven fiberglass cloth for ease of bonding using either conventional fiberglass joining techniques of proprietary Composites USA bonding systems.
   
   

SERIES 2000 Copolymer Resin -

As noted above, the HALAR® veil used in Dual Guard 2000 products offers better corrosion resistance than any other veil. The resin used in the Series 2000 system also offers excellent corrosion resistance in and of itself. In combination, Dual Guard 2000 offers an unbeatable combination of properties.

The resin system used in Dual Guard 2000 is a proprietary copolymer product developed specifically for enhanced corrosion resistance, low flame propagation and low smoke development for pipe and duct applications. In addition to its superior fire performance, very low smoke evolution, and higher temperature performance, Series 2000 resin offers excellent corrosion resistance to a wide variety of acids, solvents and bases, and specifically to the types of vapors typically found in exhaust streams from laboratory, semiconductor, plating and pharmaceutical operations. Tests of Dual Guard resin demonstrated fatigue strengths (cycles to failure) equivalent to epoxy pipe, and better fatigue strength than vinyl ester.

ASTM C-581 test results are shown above for Dual Guard 2000 exposed to a variety of reagents. These measurements reflect flex modulus and strength retention following full liquid immersion for one year-a service much more severe than a duct installation where exposures are typically diluted vapors. As can be seen form the charts, Dual Guard 2000 compares very favorably against fire retardant vinyl ester in a variety of exposure conditions.

Complete System Solutions

Dual Guard 2000 duct, fittings and dampers are available in almost every conceivable configuration in sizes as small as ½”, and as large as 24’-0”diameter. Rectangular and oval duct is available, as well as elbows, tees, reducers, transitions, stacks, fume hoods, dampers and more. See the Fitting Style Sheets for a comprehensive view of our standard fittings and components. If you cannot find what you need, call or e-mail us!

Shown right is one example of a Composites USA engineered solution to a common system problem. Large slide dampers often have a tendency to stick and jam, preventing proper operation and sometimes leading to equipment damage. The Style #330 Easy Slide damper shown has cored blades for increased stiffness without increased weight, thermoplastic track and edge guide for reduced friction, top flanged and gasketed seal to minimize system leakage, and outboard pressure clamps to fix position. (Halar track, Viton seal, stainless clamps shown).

Field Joining Dual Guard Duct

Composites USA CleanWrap Bonding System -

Installation of Dual Guard duct is straightforward with our CleanWrap bond system. Generating little or no odor, and requiring a minimum of preparation, CleanWrap bonds can be completed in less time than standard fiberglass joints, using our proprietary two part resin system and standard fiberglass reinforcements. Halar Veil is supplied as part of the package to complete a sturdy, corrosion resistant joint.

Compared to other resin systems, CleanWrap can be considered a no odor, no grinding/ sanding system, that does not require elevated temperatures for post cure!