Wire rope sheave diameter

The sheave diameter shall be the overall diameter D as shown in Figure 4-14. Sheave diameters shall, wherever practicable, be determined in accordance with recommendations given in the section titled Wire Rope,"... 

The inside diameter of socket and swivel-socket baskets should be in. larger than the nominal diameter of the wire rope inserted. Alloy or carbon steel, heat treated, will best serve for sheave grooves. Antifriction bearings are recommended for all rotating sheaves. 

Condition C—Some equipment is used under operating conditions which do not reflect the advantage of the selection of sheaves by factors under conditions A or B. In such cases, sheave-diameter factors may be selected from Figure 4-76 and Table 4-34, As smaller factors are selected, the bending life of the wire rope is reduced and it becomes an increasingly important condition of rope service. Some conception of relative rope service with different rope constructions and/or different sheave sizes may be obtained by multiplying the ordinate found in Figure 4-76 by the proper construction factor indicated in Table 4-34. 

Spiraling or curling. Allowing rope to drag or rub over pipe, sill, or any object during Installation or operation. It is recommended that a block with sheave diameter 16 times the nominal wire-rope diameter, or larger, be used during installation of the line. 

D/d = Diameter ratio of friction wheel (head sheave, deflect sheave) and wire rope. 

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