Stationary Generators used for Emergency Standby Power affected by changes to Massachusetts Fire Safety Code

Jul 10, 2017

Backup diesel generator for data center

Recent amendments to the Massachusetts Comprehensive Fire Safety Code (527 CMR 1.00) include an annual fuel quality test. The rule now requires facilities with emergency generators or legally required standby power to test their fuel according to ASTM standard D 975-11b. When testing finds that the fuel does not meet ASTM standards, it must be replaced or reconditioned, and the storage tank must be cleaned. Reconditioning fuel involves removing water found in the storage tank, filtering the fuel and adding an algaecide/biocide to kill algae and microbe growth. Additionally, the fuel must be tested after reconditioning and prior to the generator being brought back online, and then retested in 6 months to ensure it remains uncontaminated.

The rule is intended to address diesel fuel degradation.  The primary cause of diesel fuel degradation is the introduction of water into fuel. Water is formed during the heating and cooling of a storage tank in normal atmospheres. The tank ‘breathes’ through the vent pipe and water in the air condenses and falls to the tank bottom as water is heavier than diesel fuel. Microbes and algae will grow at this oil/water interface if left untreated and can clog generator fuel filters and create combustion problems.

Diesel Fuel Maintenance

To limit microbial contamination we recommend that you keep diesel fuel tanks free of water and incorporate a desiccant dryer on the vent pipe. Water levels should be checked on a regular basis and removed if greater than 1 inch. Adding a fuel stabilizer to your storage tank will preserve the fuel, limit corrosion and add lubrication.

Generator manufacturers recommend fuel polishing to be part of a regular maintenance plan for sets with long idle periods. By installing a fuel oil filtration, conditioning and maintenance system such as the Simplex SmartFilter Series, you can polish 25%-33% of your tank capacity on weekly basis. The SmartFilter is automated and fully programmable.   For good filtration performance and removal of contaminants and water, Simplex recommends circulating and filtering for an 8-hour period once each week.

Cycling diesel generator fuel through other systems like boilers is an alternative to treating fuel. If this isn’t feasible a full spectrum catalyst can be added to restore fuel to its proper combustion properties. A good maintenance program starts by testing for water in your tank after a fuel delivery; minimizing ullage space by keeping the tank full and removing any sludge that accumulates over time.  And most important, test your fuel annually and detect problems before they start.