Duration of Contract – Five Calendar years
Tentative Start Date of Contract- 01.03.2022
We will provide Sample at your Lab, specify quantity of the sample required for test.
Test to be carried out on Foam Concentrate as below requirements:-
a. Visual Appearance
A visual inspection provides the first indication of whether the foam is synthetic (clear amber liquid) or protein-based (dark brown liquid). Visual observation shall be indicated in the report.
b. Specific Gravity (SG)
The SG of a foam concentrate is calculated as its density divided by the density of water. It is a useful test for identifying the category of foam and is measured using a hydrometer or density bottle. The result depends on the temperature of the foam concentrate and so the test is to be carried out at 20°C. SG does not have a unit. Typical values for synthetic detergent- based foams are 0.99 to 1.05 and protein-based foams 1.08 to 1.18. Significant variation from these values indicates that evaporation or accidental dilution may have occurred. Test results shall be indicated in the report.
The pH is a measure of the acidity or alkalinity of a foam concentrate on a scale of 1 to 14. Neutral is 7. Acidic is less than 7. Alkaline is greater than 7. The pH of a foam concentrate to be measured at 20°C with a pH meter. Foam concentrates should be as neutral as possible to prevent corrosion of foam tanks, pH values to be highlighted in the foam test report.4
Sediment (also called sludge or undissolved solids) comprises microscopic particles of solid material in a foam concentrate. It is present in all foams at low levels and does not normally cause a problem. However, high levels may be reached if the foam is contaminated or subjected to extreme temperatures. Severe sediment may affect the flow of the foam concentrate in a proportioning system or reduce its fire fighting efficiency.
The foam sample to be put into a graduated tube and separated by centrifuge until any sediment is packed firmly into the bottom of the tube. The volume of the sediment is measured as a percentage of the foam concentrate in the tube. Sediment should not exceed 1.0%. The percentage of sediment shall be indicated in the report.
e. Surface tension
Surface tension measured with a torsion balance provides an indication of foam category. Typical values for Protein are 40 to 45; FluoroProtein 20 to 40; FFFP (Film Forming Fluoro Protein) and AFFF (Aqueous Film Forming Foams) less than 20. Units are milli Newtons per meter (mNm-1) at a given temperature. Test results to be indicated in the report.
f. Foam Properties
The properties of aerated foam made from the foam concentrate are tested because it is aerated foam that is applied to a fire. Good expansion and drainage rates are essential for producing an effective fire fighting foam blanket. The properties of any foam vary depending on the foam equipment used and the operating conditions. Thus, the foam shall be tested in accordance with US Military Specification Test for AFFF’s or the UK Ministry of Defense Standard 42-40.
Foam expansion refers to the increase in volume of a foam solution when it is aerated. The “expansion ratio” of the foam is the ratio of aspirated foam volume to the original foam solution volume. For example, the weight of an aspirated foam sample in a full 1600 ml drainage pan is 180 grams. Since 1 gram of foam solution occupies a volume of essentially 1 ml, the total volume of foam solution contained in the given sample is 180 ml. The expansion ratio is therefore calculated as 1600 divided by 180 to give a result of 8.9. To pass, a sample must exhibit a value greater than 7.0. Test results shall be indicated in the report.
The drainage rate test to be performed on the same sample as used to measure the expansion ratio. Dividing the weight of the foam sample by 4 gives the 25% volume, in ml, of solution contained in the foam. The time required in minutes for this volume of foam solution to drain from the aerated foam is called the “25% drainage time”. It provides an important indication of the stability of the foam, and is also a reliable indicator of foam category. FluoroProteins that achieve a Superior Pass must demonstrate extra long drainage rates. Test results shall be indicated in the report.
g. Alcohol Burn back Test
This test identifies alcohol resistant foams that are suitable for use on fires involving polar solvents as well as hydrocarbons. A small sample of aerated foam is applied to an isopropyl alcohol fire and simultaneously subjected to a heat source. If the time taken for the foam blanket to collapse is greater than 45 seconds then the foam is classified as Alcohol Resistant. Test results shall be indicated in the report.
h. Petrol Tolerance Fire Test
This test differentiates between Protein and Fluoro Protein foams. The foam solution is mechanically mixed with unleaded petrol to simulate forceful foam application such as base injection. The contaminated foam blanket is ignited and the time taken for extinguishment is recorded. Protein foam fails to extinguish the fire. A Fluoro Protein extinguishes the fire in less than 2 minutes 40 seconds. Fluoro Proteins that achieve a Superior Pass must extinguish the fire in less than 2 minutes. Test results shall be indicated in the report.
i. Spreading Coefficient
If the foam is film-forming, then its spreading coefficient measured against cyclohexane will be greater than zero. This value is calculated from measurements of surface and interfacial tensions of the foam solution and a known reference of cyclohexane. Test results shall be indicated in the report.
j. Interpreting the Results
The test results to be reported as found and an interpretation shall given as follows:
1. FAIL: One or more critical properties were not acceptable. Immediate replacement is recommended.
2. PASS WITH CAUTION: One or more properties only just meet minimum acceptable standards for the foam category. Replacement should be considered. A re-test is recommended after six months.
3. PASS: The sample has passed all the tests for the foam category.
4. SUPERIOR PASS: Applies to Fluoro Proteins only. The sample has demonstrated enhanced stability and fuel tolerance properties.
k. How to Get The Foam Test
One or two liter sample (depending on the laboratory requirements) of foam concentrate in a new clean polythene container, the sample bottles are to be supplied by CONTRACTOR to QatarEnergy Fire & Rescue Services in RLIC. RLIC Fire & Rescue will arrange for the samples to be collected and the filled bottles will be made available for the CONTRACTOR to collect from RLIC for testing. This includes the samples for Halul. Samples of foam concentrate should be representative of the parent stock.
A foam drum should be rolled or agitated to produce a homogeneous mix before drawing a sample from the top. For bulk foam storage tanks, circulate the contents to produce a homogeneous mix before taking a sample. Alternatively, draw samples from the top, middle and base. Use a hollow tube to take a sample from the middle. For the base sample use a side-exiting outlet pipe or alternatively run-off about 25 liters of foam first to remove any accumulated sediment. This run-off may be returned to the top of the tank. Several samples may be mixed equally to produce a single composite sample.
Samples should be clearly labeled with origin, contact numbers etc. foam type, unique sample identification number and recommended induction rate. All samples should be packed securely with a completed Foam Testing Service Form and sent to the agent. The agent will forward the samples, by air courier if necessary, to the appointed testing laboratory. Results shall be sent directly to — Representative by Fax and e-mail.
|Item||Description||Qty||Unit||Unit Rate (QR)||Amount (QR)|
|1||Testing and providing test results on foam concentrate samples in accordance with Clause2. of Appendix A – Scope of Services||—||Samples|
One of our highly competent laboratory would be taking over this project.