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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ly occur at high altitude or at very low speed. Temperature ruse then tic the limiting condition, In other wdrds, the operating limit is always determined by the maximum rating reached first. It can be any one of the three: pressure, temperature or speed. Be sure to arrange connections or taps for thermometers and mercury type pressure or vacuum gauges at or near the inlet and discharge connections of the blower. These, along with a good tachometer, will enable periodic checks of operating conditions to be made easily. PRESSURE - On pressure service; the pressure rise (bet- ween blower inlet and discharge) must not exceed the figure listed for the specific blower frame size concerned. Also, in any system where the blower inlet is at a positive pressure above atmosphere, the discharge pressure must never exceed 26 PSI (172 kPa) gauge regardless of blower size. On vacuum service, with .the discharge going to at- mospheric pressure, the inlet suction or vacuum must not be greater than values listed for the specific frame size. TEMPERATURE - Various blower frame sizes are approv- ed only for installations where the following temperature limitations can be maintained in service. A . Measured temperature rise must not exceed listed values when the inlet is at ambient temperature. Am- bient is considered as the general temperature of the space around the blower. This is not outdoor temperature unless the blower is installed outdoors. B. If inlet temperature is higher than ambient, the listed allowable temperature rise values must be reduced by 'Is of the difference between the actual measured inlet temperature and the ambient temperature. C . An average temperature between inlet and discharge up to 230 IF. (110 °C). SPEED RANGE - RCS blowers may be operated at speeds up to the maximums listed for the various frame sizes. They may be direct coupled to suitable constant speed drivers if pressureltemperature conditions are also within limits. At low speeds, excessive temperature rise may be the limiting factor as noted in the preceding example. Table 1 — Maximum Allowable Operating Conditions Frame Size Speed RPM Press. Rise Inlet Vac. Temp. Rise PSI (kPa) Hg. (kPa) F° CO 817 2250 15 (104) _ 15 (50) 230 (128) *16 *(54) *260 *(144) 824 2250 15 (104) 15 (60) 230 (128) *16 *(54) *260 *(144) 627 2250 13 (83) 15 (50) 230 (128) *16 *(54) *280 *(144) *800 Series with internal water-cooled oil coolers I Roots RCS blowers are internally and externaly treated after factory assembly to protect against normal at- mospheric corrosion before installation. The maximum period of internal protection is considered to be one year under average conditions, if closing plugs or seals are not removed. Protection against chemical or salt water at- mosphere is not provided Avoid opening the blower until ready to start installation, as protection will be lost quick. iy by evaporation. If there is to be an extended period between installation and start up, the following steps should be taken to insure corrosion protection: 1. Coat internals of cylinder, gearbox and drive end bear- ing reservoir whith Motorstor or equivalent. Repeat once a year or as conditions may require. Motorstor is oil soluble and does not have to be removed before lubricating. If desired, Motorstor may be removed from within the cylinder shortly before start up by spraying a fine mist of petroleum solvent through the blower while it is running at a slow speed with open Inlet and discharge, or it can remain in the blower if it is not harmful to the operation of the connected system. Motorstor is a product of Daubert Chemical Co., 2000 Spring Rd., Oak Brook, Ill. 60521. 2. Paint shaft extension, inlet and discharge flanges, and all other exposed surfaces with Nox-Rust X-145 or equivalent. S . Seal inlet, discharge, and vent openings. It is not recommended that the unit be set in place, piped to the system, and allowed to remain idle for extended periods. If any part is left open to the atmosphere, the Motorstor vapor will escape and lose its effec- tiveness. 4. Units are not to be subjected to excessive vibration during storage. If stored outdoors, provide coverage such as a tarpaulin or lean-to. 5. Rotate drive shaft three or four revolutions every two weeks. 6. Prior to start up, remove flange covers on both inlet and discharge and inspect internals to insure absence of rust. Check all internal clearances. Also, at this time, remove gearbox and drive end bearing cover and inspect gear teeth and bearings for rust. Because of the completely enclosed blower design, loca- tion of the installation is generally not a critical matter. A clean, dry and protected indoor location is preferred. However, an outdoor or wet location will normally give satisfactory service. Important requirements are that the correct grade of lubricating oil be provided for expected temperatures, and that the blower be located so that routine checking and servicing can be handled conveniently after installation. Effect of the location on driver and accessory equipment must also be considered. Supervision of the installation by a Factory Service Engineer is not usually required for these blowers. Workmen with experience in installing light -medium weight machinery should be able to produce satisfactory results, Handling of the equipment needs to be accomplished with care, and in compliance with safe practices. Blower moun- ting must be solid, without strain or twist, and air piping must be clean, accurately alligned and properly connected. Blower without base is to be lifted using lifting brackets provided on the blower. Make sure that the lifting bracket capscrews are tight. When blower is furnished mounted on a baseplate, with or without a driver, use of lifting slings passing under the base flanges is required. Arrange these slings so that no strains are placed on the blower casing or mounting feet, or on any mounted accessory equipment. DO NOT use the lifting brackets in the top of the cylinder. F11 C, 4