Running clearances

Impeller Since the Sundyne straight, radlal-bladed Impeller does not require close running clearances, It eliminates the necessity for over-sizing to compensate for performance deterioration common to conventional pumps. Clearance of the Sundyne Impeller Is 0.030 to 0.070 inch. 

Loosen the gland nuts one complete turn and rotate the shaft by hand to get running clearance. 

Running clearances shall meet the requirements of 2.6.4.1 and2.6.4.2... 

The running clearances specified in 2.6.4.2 do not apply to the clearances of steady bearings or interstage bushings. The clearances used shall be stated in the proposal and approved by the purchaser. 

Note The effect of bearing stiffness and damping in pumps is generally minor in comparison to that of the internal running clearances therefore, it is sufficient to analyze the bearings at their average clearance and oil temperature. 

The peak to peak displacement of the unbalanced rotor at the point(s) of maximum displacement shall not exceed 35 percent of the diametral running clearance at that point. 

A569 Record final assembly running clearances RUN CLEAR c 1 1 yes (true) 0 no (false)... 

Running clearances associated with components used to balance axial thrust or to serve as product-lubricated internal bearings may be the manufacturer s standard, provided these clearances are stated as exceptions to this International Standard (see 5.7.4) in the proposal and are approved by the purchaser. If the manufacturer s standard clearances are based on material combinations exhibiting superior wear characteristics, supporting data shall be included in the proposal. 

Unless otherwise specified, the need for hard-facing and the specific hard-facing material for each application is determined by the vendor and described in the proposal. Alternatives to hard -facing may include opening running clearances f.7.4) or the use of non-galling materials, such as Nitronic 60, Waukesha 88, or non-metallic materials, depending on the corrosiveness of the pumped liquid. 

The measurements were conducted on a rotary viscometer Viscoster UTS 50 of HAAKE. Applications software was used for treatment of the results. A Cone Board instrument was used. Radius = 25 mm Aperture angle = 3.49 x 10" rad kegel PK5 2.0 GRAD cone running clearance = 100 pm sample volume = 1.2 cm. The measurements were conducted at shear rate 30 - 2.2 X 10 s and within a temperature range from -20 to 50 °C. Sample holding time at preset temperature before measurements was 20 min. 

Running Clearances. Running clearance must be sufficient to prevent internal rubbing contact witiiin the design region (para. 5.1.6) and is subjected to the maximum allowable flange loads as specified in para. 5.1.2. 

---