TECH TIP #7
Description
Many Loaded Stream/Anti-freeze charges are available on the market for freeze protecting stainless steel water extinguishers. The Amerex Model 506 charge has been used successfully by our Distributors for over 20 years with no reported corrosion, pressure guage damage or adverse effects. Do not use any other formulation and jeopordize the warranty or suffer the consequences of damage to your customer’s extinguisher or property.
Amerex has determined that the Model 506 Loaded Stream/Anti-freeze charge has an indefinite protection life span. NFPA-10 calls for an annual discharge of the agent (NFPA 4-4.1.1) to check for proper extinguisher operation. The solution should be discharged into a clean pail, for re-use after checking for the freezing point.
The following procedure has been developed for checking the solution freeze point while performing the Annual Maintenance. Proper test equipment as prescribed below is essential to performing a valid test:
POUR SOLUTION INTO A 300 ML GRADUATED CONTAINER
CHECK SPECIFIC GRAVITY WITH A HYDROMETER
A minimum specific gravity of 1.330 will assure freeze protection to – 40°F. A reading lower than this means that the charge should be replaced.
Testing can be accomplished using equipment purchased from Fisher Scientific:
P/N: 11-520B Hydrometer
P/N: 08-532F Cylinder (300 ml)
ISO 14001