64 



CREOSOTE OIL 



The oil shall be a distillate of coal-gas or coke-oven tar. It shall 

 comply with the following requirements: 



1. It shall not contain more than 3% water. 



2. It shall not contain more than 0.5% of matter insoluble in 

 benzol. 



3. The specific gravity of the oil at 38 C. compared with water at 

 15.5 C. shall be not less than 1.045. 



4. The oil shall contain from 5 to 10% tar acids. 



5- The oil shall contain not less than 10% naphthalene. 



6. The distillate, based on water-free oil, shall be within the 

 following limits: 



Up to 210 C. not more than 5% 



Up to 235 C. not more than 25% 



Up to 315 C. not less than 45% nor more than 75% 



Up to 355 C. not less than 70% nor more than 90% 



7. The specific gravity of the fraction between 235 C. and 315 C. 

 shall be not less than 1.03 at 38 C. compared with water at 15.5 C. 



The specific gravity of the fraction between 315 C. and 355 C. 

 shall be not less than 1.09 at 38 C. compared with water at 15.5 C. 



8. The residue above 355 C. shall have a float-test of not more 

 than 50 seconds at 70 C. 



9. The oil shall yield not more than 2% coke residue. 



10. The foregoing tests shall be made in accordance wltn the 

 standard methods of the American Wood-Preservers' Association, with 

 the exception of those for tar acids and naphthalene, as specified in 

 clauses 4 and 5, which shall be made in accordance with the methods 

 of the American Railway Engineering Association. 



TREATMENT AND INSPECTION 



Treatment shall be by the Boulton process (boiling under vacuum). 



Green or Fresh Cut, Water Stored and Partially 

 Air Seasoned Piling 



Period of Artificial Seasoning. After the piles are placed in the 

 treating cylinder, they shall be immersed in creosote oil having a tem- 

 perature of about 160 F. and kept covered during the entire boiling 

 period of the process, the oil level being at least four (4) inches above 

 the topmost pile. 



After filling the treating cylinder with creosote oil as above speci- 

 fied, connections between condenser and vapor drum on treating cylin- 

 der shall be opened, steam shall then be admitted through the heating 

 coils and shall be so regulated that the temperature inside the treating 



