FIELD DOCUMENTS AND WORK PLANS 1992-1999

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11A-6.02. Impeller. The impeller shall be a one-piece casting completely machined on all exterior surfaces, and statically balanced. The interior water passages shall have uniform sections, smooth surfaces, and be free from cracks and porosity. The impeller shall be securely locked to the shaft so it will not be loosened by reverse rotation, but it shall be readily removable. Pumps shall be selected such that the impeller size, at the stated design conditions, is not greater than 85% of the maximum diameter impeller for that pump. 11A-6.03. Shaft and Shaft Sleeves. The shaft shall be completely machined. Deflection at the stuffing box shall not exceed 0.002 inch at any head in the operating rage. A suitable splash deflector shall be mounted on the shaft adjacent to the frame bearing housing. The shaft shall be provided with a replaceable sleeve extending from the impeller through the stuffing box. The sleeve shall be positively secured to the shaft and shall be sealed to prevent leakage between the shaft and the sleeve. After assembly on the shaft, total runout shall not exceed 0.002 inch. 11A-6.04. Stuffina Box. The stuffing box for the pumping unit shall contain a single mechanical seal . 11A-6.05. Frame Assembly. The frame assembly shall rigidly support the rotating element with two bearings. The outboard bearing shall carry both axial and radial pump loads. The assembly design shall permit axial adjustment of the rotor without dismantling the pump. Bearing enclosures shall keep out contaminants and retain the lubricant and shall have adequate provisions for adding and draining lubricant. The frame shall provide ample clearance for stuffing box maintenance. 11A-6.06. Bearings. Bearings shall be either oil or grease lubricated antifriction type. Bearings shall have an AFBMA LU Life Rating of 40,000 hours at specified operating conditions. le pump shaft speed shall not exceed the bearing manufacturer's limitation. 11A-6.07. Flexible Coupling. The pump coupling shall have a horsepower rating 1.25 times the motor nameplate horsepower when the misalignment is within the manufacturer's tolerance limit. Coupling design shall permit removal of the pump rotating element without disconnecting the piping, moving the drive unit, or axial movement of the coupling halves on the shaft. 11A-6.08. Accessories. Each pump shall be provided with lifting eyebolts or lugs; plugged gauge cock connections at the suction and discharge nozzles; tapped and plugged openings for casing assembly and (MARLEY FSSF ) (CONTRACT NO. 13) 11A-4 (11654.812 )