65 



cylinder is kept gradually rising, as. fast as the condensation will per- 

 mit, until a temperature of 215 F. is reached. Having reached this 

 temperature of 215 F., at least a twenty (20) inch vacuum shall be 

 produced and maintained in the treating cylinder, the escaping vapors 

 being drawn into the condenser, and this operation continued until such 

 time as the amount of condensation collected in the hot well of the 

 condenser does not exceed one-tenth (1-10) of a pound of water per 

 cubic foot of timber in charge per hour, with a vacuum of not less than 

 twenty (20) inches and a temperature of not less than 215 F., and 

 not more than 220 F. inside the treating cylinder, the latter tempera- 

 ture being regarded as the absolute maximum that will be allowed. 



Pr(\isure Period. After the period of artificial seasoning has been 

 completed, as specified in the foregoing, the temperature inside the 

 treating cylinder shall then be allowed to drop to approximately 200 

 F. The treating cylinder shall then be filled with hot creosote oil 

 (temperature about 170 F.) from the operating tank; the treating 

 cylinder being full, all vents shall then be closed and more oil pumped 

 into the treating cylinder from the operating tank, until the pressure 

 gauge on the treating cylinder records a five (5) pound pressure (this 

 to insure that the treating cylinder is full). Creosote oil from a meas- 

 uring tank shall then be forced into the piling by means of a pressure 

 pump at a pressure not to exceed one hundred and sixty (160) pounds 

 per square inch, and this operation continued until such time as the pil- 

 ing has absorbed the amount of creosote oil specified by the purchaser, 

 under such conditions as will insure its complete retention in the wood 

 after the treating cylinder has been drained- This having been accom- 

 plished, the piling may be removed from the treating cylinder, as soon 

 as- the temperature within the treating cylinder has dropped below 

 200 F. A final vacuum will be allowed for not to exceed one (1) hour, 

 to recover drip. 



Inspection of Treated Material 



Physical Condition. After the piling has been removed from the 

 treating cylinder and allowed to cool in the air for not less than six 

 (6) hours, it must be free from all heat checks, water bursts, and other 

 defects due to improper treatment, which would, in the opinion of the 

 inspector, impair its usefulness or durability for the purpose intended. 



Absorption. Shall be as specified by the purchaser. 



Penetration. Piling shall be accepted upon the showing of pene- 

 tration of creosote oil in each pile. This penetration must be based 

 on black or very dark oil and in no case will a light discoloration of 

 the wood due to treatment be taken into consideration in measuring the 

 depth of penetration upon which the piling is to be accepted. The test 

 for penetration shall be made by boring the piling midway between ends 

 with either an increment borer, or a five-eights (5-8) inch auger, the 

 choice of which shall be optional with the inspector. All holes so bored 



