At Thompson Specialties Middle East we specify, install, test and maintain all types of Foam Fire Fighting Systems. Our service follows the standards as adopted by Qatar Civil Defense and NFPA 11,16, 25 and other codes as determined by the hazard. We test all hardware, detection and control systems as associated with each system. From the basic fixed monitor protecting a flammable liquids area, to an automatic system controlling monitor nozzles over a LNG Filling Area, These systems can be robust with manual over ride so the operator can remotely control the flow and aim of the Monitor from the comfort of a control room. We can help insure these systems are working properly as designed.
Testing of the Foam concentrates as per code and insuring the proportioning is per installatiio specifications is our speciality. When you really want to know if the system is working properly. Contact US
In Summary, Performance Testing of Foam Proportion Systems Should follow these requirements
1. Test system to insure It can deliver foam and water mixture as designed
2. Tested Annually (Minimal)
3. All components thoroughly inspected
4. System operated at percentages and flow and pressures as per Manufacture, QCD and AHJ requirements
5. Measure Calibration Accuracy (cross verify results)
6. Use Same Test Points each test (to compare with previous results)
7. Use acceptable testing method, Refractometer, conductivity actual flow etc.
8. Test all Concentrate Types and associated Ratio/parameters
9. Compare test results to design and actual Installation results.
Foam Testing Services
Verifying that a firefighting foam system accurately proportions foam and water is critical to the system’s effectiveness in the event of a fire. If the premix solution is mixed too lean—not enough foam concentrate and too much water—it may not be able to extinguish the fire. If the premix solution is mixed too rich—too much foam concentrate and not enough water— there is a risk running out of foam before the fire is fully extinguished. At Thompson we can help to determine if foam solution discharged from a system or apparatus is mixed or proportioned as recommended by the foam concentrate manufacturer.
Conductivity Testing
Our equipment utilizes conductivity, a measurement of the ability of liquids to conduct electricity, to determine the amount of foam concentrate in foam solutions. Conductivity is the method adopted by most foam concentrate manufacturers and many foam equipment listing and approval agencies to determine the accuracy of foam proportioning equipment. Although not as costly as some digital conductivity meters alone, this kit is adequate to determine proportioning accuracy for most fire service applications.
Other Methods to Determine Foam / Water Ratio
> Substituting Water for Foam Concentrate
> Measuring Foam Concentrate Pump output directly
> Determining Foam Percentage using a Refractometer
NFPA 25 – Standard for the Inspection, Testing and Maintenance of Water-Based Fire Protection Systems, 2014 Edition, recommends that foam systems be flowed annually and that the foam solution be tested to verify the concentration. Furthermore, NFPA 11 – Standard for Low-, Medium-, and High-Expansion Foam, 2010 Edition recommends the following in Section 11.6.4 – “Foam concentration shall have one of the following proportions: 1) not less than the rated concentration and 2) no more than 30 percent above the rated concentrate or 1 percentage point above the rated concentration (which-ever is less).” NFPA 11, Annex B recognizes three methods for determining the concentration of a foam solution. The foam solution can be analyzed using a refractometer or a conductivity meter. Alternatively, the concentration can be determined by measuring the flow rates of both the water and the foam solution.
In order to calculate the concentration of the foam solution using either refractive index or conductivity, foam and water are mixed at known concentrations and the refractive index or conductivity of the known solutions are compared to the unknown system solution. In order to ensure accuracy, the following items should be considered:
- The standard solutions must be mixed accurately.
- The water used to mix the standard solutions must be representative of the water used in the foam proportioning system. This is particularly important when using the conductivity method as the conductivity of the water can vary significantly.
- The foam concentrate used to mix the standard solutions must be representative of the foam concentrate used in the foam proportioning system. Keep in mind both the refractive index and conductivity of different brands of foam concentrate can vary significantly and can also vary significantly from lot to lot of the same brand of concentrate.
- The refractometer or conductivity meter must provide an accurate value and variables such as temperature must be taken into account.
- The system solution must be generated at the flowrates that mimic the flows in a fire situation.
Often times, the proportioning verification is completed in the field. The advantage of field verification is the system can be immediately adjusted should it be out of specification. We can also verify results using a laboratory. This is because the mixing and testing is more accurate and the variables affecting the result can be controlled. Should we determine laboratory testing is required, a representative sample of the concentrate and water must be sent to the laboratory along with a sample of the solution generated from the system. Thompson can assist with all steps required to prove to the Civil Defense of Qatar or other Authority have Jurisdiction that the Foam is stable and within quality standards as mentioned on this page.
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