Page 312 - Reciprocating Compressors Operation Maintenance

Overhaul and Repair of Reciprocating Compressors 2t97

TABLE 4-9
CROSSHEAD NUT TORQUE VALUES

Thread Diameter Foot Pounds
(8 THD,) except as shown
i-yr 1850-1950
l
2-A" 2600-2700
2-T 4050-4150
3-%" 8500-8600
4" 11400-11500
4" 11400-11500
3
4- /"-6THD 19200-19300
4-%" -6 THD 19200-19300
5" -6 THD 29800-29900
5-%" - 6 THD 29800-29900

CONNECTING ROD REPAIRS

• Rebore the large end to re-establish the correct bearing crush and to
return the bore to standard size.
• Straighten rods with heat. Cold straightening is limited by the
amount of bend.
• Install new crosshead pin bushings. Fit pin to bushing.
• Straighten the rod by machining the large end of the rod true to the
crosshead end. Avoid having to remove bend.
Note: Repair by welding is not recommended.

CROSSHEAD REPAIRS

Crossheads, like other compressor components, may be successfully
rebuilt if the proper materials and procedures are used.

• Non-adjustable. Rebabbitt and turn to size on babbitted crossheads.
This may be done by metal spray.
» Non-adjustable, not babbitted. Repair by machining round. Consider
application of babbitt to faces. This improved type of crosshead can
also be welded up and turned to size.