Articles

An in-depth look at NFPA 11 and 25 percent concentration testing and what you can do about it in the field

by Grant Lobdell

by Grant Lobdell

All National Fire Protection Association (NFPA) documents reference an authority having jurisdiction (AHJ) at some point or another.  For example, per 5.3.1.1 in the current, 2017 edition of NFPA 25 Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, “sample sprinklers shall be submitted to a recognized testing laboratory acceptable to the authority having jurisdiction for field service testing.”  To fulfill requirements such as these, a person needs to know what and who their AHJ is.

by Joan Leedy

At Dyne, we are often asked “What is the shelf life of my firefighting foam concentrate?” And the answer is – that depends. There are many factors that can affect shelf life. I will discuss the major ones here.

The Brand and Model of Foam – Though there are some similarities among the foams produced today, none are identical and some formulations will have longer shelf lives than others. Check with the manufacturer of your foam to obtain a shelf life estimate. Manufacturers typically run accelerated aging studies to predict the shelf life of a formulation.

Materials of Construction – The foam manufacturer should be able to provide acceptable materials of construction for storing their respective foam concentrate in order to maximize shelf life. This will include the tank, piping materials, valves, pumps and other surfaces that come in contact with the foam concentrate.

The 2016 edition of the National Fire Protection Association Standard 11 - High, Medium and Low, Expansion Foam also provides recommendations on the materials of construction in contact with firefighting foam concentrate. NFPA 11 recommends that foam concentrate piping and fittings be constructed of brass (red or naval), bronze, stainless steel (304 or 316) or “other material, in accordance with the foam concentrate manufacturer’s certification of compatibility with the foam concentrate and as approved by the AHJ”. Carbon steel piping or fittings is not recommended for use with foam concentrate. See NFPA 11 Section 4.7.

An additional concern with materials of construction can be galvanic corrosion when using dissimilar metals. Dielectric components are recommended to insulate dissimilar metals – see NFPA 11 section 4.7.1.5.

by Grant Lobdell

According to the current, 2017 edition of NFPA 25 Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, sprinklers are to be sent in for field service testing on a periodical basis according to 5.3.1.  This field service testing is further defined in the annex of the standard under section A.5.3.1.1 stating that sprinklers should be laboratory tested for sensitivity and functionality, specifically.  While the 2017 edition of NFPA 25 does discuss sensitivity and functionality requirements to some degree, the upcoming 2020 edition of NFPA 25 will have much more defined requirements.*  Note that these requirement changes have already been implemented at Dyne and other sprinkler labs across the country.  For periodical testing purposes, a sprinkler is functional if the waterway clears at 7 PSI.  The periodical sensitivity requirements for a sprinkler will be defined as shown in Table 1.

by Grant Lobdell

When you send foam samples to Dyne for quality condition testing, the tests Dyne completes fall into two categories on the report: physical properties and performance properties.  Physical properties, including refractive index, density, viscosity, and pH, are inherent attributes of the chemical composition of the sample and are completed on the concentrate prior to dilution.   Performance properties, including expansion ratio, drain time, and spreading coefficient (if applicable), are measures of foam quality and are measured after diluting the concentrate to its nominal concentration.  Ultimately, a foam sample’s overall Pass or Fail designation will depend on the foam quality*.

How does Dyne determine if a physical property is “In Spec”?

Each foam product’s physical specifications are determined by the manufacturer and are published on the foam product technical datasheet.  Dyne compares values obtained during periodical testing to these published ranges to determine if the result falls within the manufacturers stated range.  If the result does, it is deemed “In Spec”.  If the result doesn’t, it is deemed “Out of Spec”.

by Joan Leedy and Jennie Novak

Partnering to Protect Lives & Property has been Dyne’s motto for 20 years. Over those 20 years, Dyne Technologies has come a long way but we’ve always been proud of our high-quality test results with timely delivery and unparalleled customer service. Recently rebranded as Dyne Fire Protection Labs, we have grown from a team of a just a few people to many lab technicians and administrative staff with a variety of backgrounds and skills.

by Grant Lobdell

Firefighting foam concentrates are designed to be mixed with water prior to use.  For most fixed foam systems, this is done automatically when the system is triggered by a fire event through the use of proportioning equipment resulting in foam solutions typically ranging anywhere from 1% to 6% foam concentrate (99 to 94% water, respectively) depending on how the foam concentrate has been formulated, certified, and listed.  Ensuring that both the foam concentrate and the proportioning equipment in this type of system meet periodical testing requirements will result in confidence in the fire protection system.  Performance degradation of either could be catastrophic.  However, for some portable systems, the foam concentrate may be mixed into a solution well before the event of a fire and then stored prior to use.  In this case, performance of the foam solution itself and not the concentrate and proportioning equipment must be evaluated.