New Bulletin : Intumescent Epoxy Fireproofing

Training Objective : The reader should understand the value of intumescent epoxy fireproofing, how it functions and its potential applications.

Intumescent Fireproofing : Intumescents are substances that expand or well when exposed to heat, as shown in the before and after pictures below.  This swelling of the material increases its volume and decreases its density.  The expanded materials is a poor conductor of heat, thus retarding the transfer of heat and from fire to the protected object.

Before	After

Cementitious 'vs' Intumescent Fireproofing : The most widely used fireproofing materials in the process industries consist of low density, gypsum base or cementitious materials.  These materials are a mixed mortar application and may be trowel or spray applied.  These materials are fairly inexpensive and are readily available along with the skilled labour needed to apply them.  The drawbacks of these materials include their weight (a structural issue), bulkiness, susceptibility to damage (due to weather, structural movement/vibration, and impacts) and the potential for Corrosion Under Fireproofing (CUF).  As a result of these drawbacks it is not common to see them used (successfully!) in applications other than structural steel fireproofing.

Intumescent coatings are spray applied (formulated in a water, solvent or epoxy base) and are more like paint than a plaster.  The fire resistance rating of the coating is established by its thicknesses (11mil of some products can provide a 3 hours hydrocarbon fire rating).  The primary advantages of these materials are their lightweight, compactness, resistance to impact and other damage, and the fact that the coating precludes the potential for CUF.  The drawbacks of these materials are that they are relatively expensive, difficult to remove and require specially skilled labour to install.  In addition, some of these materials are commonly used to protect valve operators (shown above), cable trays, vessel shells and structural steel.  Intumescents are particularly useful in those applications where it is difficult to prevent rain water intrusion using cementious or other traditional fireproofing products.

Int. Coated I-Beam	Int. Coated LPG Bullets

For additional information, refer to API Publication 2218, Fireproofing Practices in Petroleum and Petrochemical Processing Plants, manufacturer's literature and your National & Local Fire Codes.

 

Previous Bulletins :

Inspection of Concrete Passive Fire Protection - March 2010

Petroleum Bulk Plant Incidents by USFA - February 2010

Evaluating fire response needs and determining the best response solution - January 2010

Access and Water Supply : Underground Water Pipe Depth-of-Cover - December 2009

The Value of Water Flow Information - November 2009