ASTM D6823 Specification for Commercial Boiler Fuels with Used Lubricating Oils
6. General Requirements
6.1 The fuel oils specified herein shall contain a minimum of 25 % volume of used lubricating oil-derived products, the balance being a Specification D396 fuel oil or suitable refinery stocks.
6.2 The fuel oils shall be homogeneous fluids consisting primarily of hydrocarbons. RFC shall remain homogeneous and uniform in storage and shall not separate by gravity into layers in normal operating conditions.
NOTE 4 - Prolonged storage or equipment down time may necessitate circulation of the fuel oil in-tank to prevent such separation. The buyer and seller should agree on any requirements for long-term homogeneity.
6.3 The fuel oil shall not contain excessive amounts of organic or inorganic acids, or both, and shall be free of solid or fibrous matter that could cause system handling or maintenance problems. The buyer and seller should agree on any requirements for particle size.
NOTE 5 - The fuels defined by this specification are appropriate for burners capable of handling and combusting fuels with potentially high metals and higher ash content than Specification D396 fuels.
7. Detailed Requirements
7.1 Grade RFC4 - The requirements for this type of fuel are presented in Table 1 and include fuels in the viscosity range below 5 mm2/s (cSt) at 100°C according to Test Method D445.
7.2 Grade RFC5L - The requirements for this type of fuel are presented in Table 1 and include fuels in the viscosity range 5.0 to 8.9 mm2/s (cSt) at 100°C according to Test Method D445.
7.3 Grade RFC5H - The requirements for this type of fuel are presented in Table 1 and include fuels in the viscosity range 9.0 to 14.9 mm2/s (cSt) at 100°C according to Test Method D445.
7.4 Grade RFC6 - The requirements for this type of fuel are presented in Table 1 and include fuels in the viscosity range 15.0 to 50.0 mm2/s (cSt) at 100°C according to Test Method D445.
NOTE 6 - Refer to X1.3. Viscosity measurements may be provided/agreed to other than the above listed temperatures.
NOTE 7 - In the U.S., RFC must also meet US EPA on-specification parameters for recycled used oil fuels as defined under 40 CFR Part 279, 40 CFR Part 761, and air quality regulations for particulate matter.
7.5 The properties listed in this specification are those of greatest significance in obtaining acceptable performance of the burner. Only referee test methods are shown in Table 1. (See Section 8 for alternate test methods and Appendix X1 for significance of test requirements.)
7.5.1 Ash Content - Specific burners/boilers may be able to handle higher ash contents without increasing maintenance. Buyer/seller may agree on an alternate ash content based on specific equipment capabilities.
7.6 A representative sample shall be obtained for testing. Practices D4057, D4177, or other comparable sampling standards should be followed. In case of dispute, Practice D4057 shall be the referee practice. A minimum sample size of about 1 L is recommended for each sample taken (before compositing). Sample handling and mixing shall comply with Practice D5854.
7.7 Testing frequency and any modifications of limiting requirements to meet special operating conditions shall be agreed upon by both the buyer and the seller.
NOTE 8 - It is possible that one or more of the parameters listed in Table 1 may be used as an indicator of when more extensive testing is required.
