Jack bolts

To correct this condition with an opened impeller, it s nece,s,sary to perform an impeller adjustment to correct the strict tolerance between the blades and the volute. Some back pullout pumps arc designed with jack bolts on the power end of the bearing housing to easily perform this adjustment without pump disassembly. 

Inspect gasket surfaces for knots and irregularities. Look for bent dowel pins and misaligned jack bolts, dirt and any other factor that might lead to misalignment. 

Figure 2.24 illustrates the basic components of a sheet extrusion die. The die is built in two halves the part for easier construction and maintenance. The use of a jack bolt facilitates separation of the die halves when the die is full of plastic. The die lip can be adjusted (across the entire lip length) to enable the processor to keep the thickness of the extruded sheet within specification. 

For lower pressure applications No jack bolts required... 

Abj = Area required, jack bolts, in R2 = Radial load due to pressure. Lbs/... 

Sbi Jack Bolts Design Temp Bearing Stress, Use. 9 Fy of Flange Material ... 

The jack bolts are used to remove the end plug in die event diat the gasket becomes fused to the inside wall of the flange. 

The jack bolts must be capable of exerting enough force on the end of the flange to break the weld in shear. 

Use the same quantity of jack bolts as main studs as a starting point. 

Stagger jack bolts in between the main smds to obtain adequate wrencb clearance. 

It is common practice to leave the jack bolts in the retainer ring during operation. 

Maintain at least one bolt diameter between the jack bolt circle and the OD of the retaining ring. 

The bolt circle required for the jack bolts, Cbj, is dependent on wrench clearances and spacing between nuts. Recommended wrench clearance and dimensions of nuts are contained in the following Table. 

Install the chain on the sprockets, then begin increasing the distance between the sprockets by turning the jacking bolts do this until the chain is snug but not tight. To set the proper chain sag, deflect the chain... 

Next, make sure the shafts are parailei. This is done by measuring at different points on the shaft and adjusting the shafts until they are an equal distance apart. Make sure that the shafts are pulled in as close as possible before performing this procedure. Then you can use the jacking bolts to move the shafts apart evenly after the belt is installed. See Figure 23.19-... 

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