ANSI AWWA B702-2018 pdf free download – Sodium Fluorosilicate.
Sec. 5.1Sampling
Sampling shall be conducted in accordance with this section of the standard.Each sample container shall be labeled and shall be signed by the sampler. A chain-of-custody form shall accompany all samples and shall be properly completed bythe individuals collecting samples.
5.1.1 Sampling point. Samples shall be taken at the point of destination;the point of manufacturing, or the point of repackaging, and the sampling pointshall be clearly identified.
5.1.2 Sampling device. Sodium fluorosilicate may be sampled using asampling tube that is at least 3 in.(19 mm)’ in diameter. If the sodium fluorosilicateis handled by conveyor or elevator, a mechanical sampling procedure may be used.The procedure must provide a representative sampling of the entire shipment thatis being handled.
5.1.3Amount of shipment to be sampled. If the sodium fluorosilicate ispackaged, 5 percent of the packages shall be sampled.No sample for testing shall betaken from a broken package. Samples from individual packages shall be combinedto form a composite sample.
5.1.4Sample size and handling. The composite sample, weighing at least16 lb (7.3 kg), shall be mixed thoroughly and divided in the following manner:
1. Divide into four 4-lb (1.8-kg) sections.
2. Select alternate quarters.
3. Re-divide each to provide eight 1-lb (0.5-kg) sections.
4. Select six 1-lb(0.5-kg) samples.
5.1.5Samaple storage. The 1-lb(0.5-kg) samples shall be sealed in airtight,moisture-proof plastic or glass containers, each carefully identified by a label signed
by the sampler. Two samples are to be used by the purchaser for the tests specifiedin Sec.5.2.The other four shall be retained for at least 30 days after the date ofreceipt to be used for retesting as provided in Sec. 5.3.
Sec.5.2Test Procedures
Testing of sodium fluorosilicate shall be conducted in accordance with theprocedures presented in this standard.Alternate procedures can be used only withwritten approval from the purchaser. In any case of conflict, the test procedures ofthis standard shall prevail.
5.2.1 lest samples. Test samples shall be obtained from the 1-lb (0.5-kg)samples taken in accordance with Sec. 5.1.Samples shall be stored in an airtightcontainer and unsealed only when it is necessary to remove quantities of materialfor testing.Removal of material shall be conducted as rapidly as possible to avoidchanges in moisture content, and the sample container shall be resealed for futurereference.
5.2.2 lest procedure for size. Rapidly weigh approximately 100 g of sampleto the nearest 0.1 g and screen until a constant weight is achieved on the appropriateUS Standard Sieve Series to determine compliance with the size requirements ofSec.4.1. Weigh to the nearest 0.1 g the amounts of material passing through thesieve or being retained on the sieve.Report each portion of material passing throughthe sieve or retained on the sieve as a percent of the total initial sample.The entireprocess should be performed in a dry atmosphere and as quickly as possible.
5.2.3 lest procedure for insoluble matter.
5.2.3.1 Procedure.
1. Weigh 2 g of the sample that has been previously dried at 105C to aconstant weight and transfer into a beaker. Dissolve in 500 mL of hot deionizedwater. Generally,15-30 min is sufficient time for dissolution.
2. Filter through a tared Gooch crucible or a tared fritted-glass filterof medium porosity.Wash with at least six separate 25-mL portions of boilingdeionized water, allowing the crucible to drain between washings. Dry the crucibleor filter at 105C to a constant weight.ANSI AWWA B702 pdf download.