Opening of Bids - One (1) or More New Positive Displacement Hydro-Excavating Machine with Tandem Axle Cab & Chassis Spec U - Best Equipment Co., Inc.

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f Before starting the installation, remove plugs, covers or seals from blower inlet and discharge connections and in• spect the interior completely for dirt or foreign material. If cleaning is required, finish by washing the cylinder, headplates and impeller thoroughly with a petroleum sol- vent such as DuPont Triclene D. After this, turn the drive shaft by hand to make sure that the impellers turn freely at all points. Anti -rust compound on the connection flanges and drive shaft extension may also be removed at this time with the same solvent. Then cover the flanges again to keep out dirt until ready to connect the air piping. Washing out is not required if the interior is found to be clean. The cor- rosion inhibitor used will vaporize and disappear during operation. Care, plus consideration of all possible problems, will pay dividends when arranging the blower mounting. This is especially true when the blower is a "bare" unit, furnished without a baseplate. The convenient procedure may be to mount such a unit directly on a floor or small concrete pad, but this generally produces least satisfactory results. It definitely causes the most problems in leveling and alignment, Direct use of structural framing members is also not a recommended mounting. If unavoidable, the members must be rigidly reinforced when part of a building, and spring type mountings should not be used. Noise transmission can usually be reduced by use of a cork insulating pad 1 to 2 inches (25 to 60 mm) thick. The pad should be supported by a full steel plate attached to the structure, with a rigid con- crete slab laid on top of the cork to carry the blower and driver. For a blower without base, it is recommended that a well anchored and carefully leveled steel or cast iron mounting plate be provided at the installation point. The plate should be at least 1 inch (25 mm) thick, with Its top surface machined flat, and large enough to provide leveling areas at one side and one end after the blower is mounted. It should have pro- perly sized studs or tapped holes located to match the blower foot drilling. As an alternative, smaller plates at each end of the blower may be used. This is more complicated usually making leveling more difficult, and can produce twist or strains in the blower. Use of a high quality machinist's level is important. With the mounting plate in place and leveled, set the blower on it without bolting and check for rocking. If it is not solid, determine the total thickness of shims required under one foot to stop the rocking. Place half of this under each of the diagonally -opposite short feet, and tighten the mounting studs or screws. Rotate the drive shaft to make sure the impellers still turn freely. If the blower is to be direct coupled to a driving motor, consider the height of the motor shaft and the necessity for it to be alligned very ac- curately with the blower shaft. Best arrangement is for the blower to be bolted directly to the mounting plate while the driver is on shims of at least % inch (3 mm) thickness. This allows adjustment of motor position in final shaft alignment by varying the shim thicknesses. When blower and driver have beet factory mounted on a common baseplate, the assembly will have been properly aligned and is to be treated as a unit for leveling purposes. Satisfactory installation can be obtained by setting the baseplate on a concrete slab that is rigid and free of vibra- tion, and leveling the top of the base carefully in two direc- tions so that it is free of twist. The slab must be provided with suitable anchor bolts. The use of grouting under and partly inside the base, after it has been carefully leveled by shimming, is recommended. It is possible for a base -mounted assembly to become twisted during shipmen4 thus disturbing the original align- ment. For this reason, make the following checks after the base has been leveled and bolted down. Disconnect the drive and rotate the blower shaft by hand. It should turn freely at all points. Loosen the blower foot hold-down screws and determine whether all feet are evenly in contact with the base. If not, insert shims as required and again check for free impeller rotation. Finally, if blower is direct coupled to the driver, check shaft and coupling alignment carefully and make any necessary corrections. In planning the installation, and before setting the blower, consider how piping arrangments are dictated by the blower design and assembly. Drive shaft rotation is established ac- cordingly, and is indicated by an arrow near the shaft. The rotation cannot be reversed at will. Blower inlet flange has cast marking on the flange outer diameter. Inlet piping should be connected to this flange. When a blower is DIRECT COUPLED to its driver, the driver RPM must be selected or governed so as not to ex- ceed the maximum speed rating of the blower. Refer to LIMITATIONS for allowable speeds for various blower sizes. A flexible type coupling should always be used to con- nect the driver and blower shafts. Coupling halves must be accurately aligned, and a suffi- cient gap between shaft -ends provided so that side strains and end thrust on either shaft are avoided or minimized. This will require considerable care in the mounting of the driver. The two shafts must be in as near perfect alignment in all directions as possible, and the gap must be established with the motor armature on its electrical center if end play exists. The following requirements for a good installation are recommended. Coupling halves must be fitted to the two shafts with an interference fit. Maximum deviation in off- sete alignment of the shafts should not exceed .W5" (.13 mm) total indicator reading, taken on the two coupling hubs. Max- imum deviation from parallel of the inside coupling faces should not exceed .001" (.03 mm) when checked at six points around the coupling. When a blower is BELT DRIVEN, the proper selection of sheave diameters will result in the required blower speed. This flexibility can lead to operating temperature problems caused by blower speed being too low. Make sure the drive speed selected is within the allowable range for the specific blower size, as specified under LIMITATIONS. Blower sheave minimum diameter is 13.2" (385 mm) and maximum width is 7.19" (183 mm). . Belt drive arrangements usually employ two or more V- belts running in grooved sheaves. Installation of the driver is less critical than for direct coupling, but its shaft must be level and parallel with the blower shaft. The driver should be mounted on the inlet side of a vertical blower (horizontal piping) and on the side nearest to the shaft on a horizontal blower. The driver must also be mounted on an adjustable base to permit installing, adjusting and remov- ing the V-belts. To position the driver correctly, both sheaves need to be mounted on their shafts and the nominal shaft center distance known for the belt lengths to be used. Install the blower sheave so that its inner hub face is not more than', inch W mm) from the drive end cover. The shaft fit should be such that the sheave can be worked into place 5