CON-SERV offers a variety of alloys which are approved for nuclear, structural, industrial and bridge applications. These bronzes are lubricated to approximately 25% of the bearing surface. The standard lubricant takes temperatures to 250°F. Lube 1 has a temperature range from 200°F to 500°F. Lube 2 has a temperature range from 500°F to 800°F. For nuclear applications (normal containment, atmosphere including borated water spray, and radiation below 2.2 x 106 rads.). Use Lube AE for all temperatures to 800°F. Slots and holes if required shall be fabricated in the bearing manufacturer's plant. Designers use 0.15 as a practical figure and increase this for high temperature applications ...
Generally used for temperatures from 500°F to 1000°F This material is a form of gray cast iron which is produced utilizing flake graphite. For Meehanite sliding against a ground steel plate (63 to 125 RMS) a design friction factor of 15% is appropriate. Grade Type CA50 (50000 Tensile Strength) is usually specified for bearing applications.
Wear is negligible when sliding against itself. Graphite may be purchased bonded to steel back-up plates or structural shapes as the job may require. Bonding epoxy is available.The maximum temperature limit on the epoxy is 300°F. Hi-temperature applications require mechanical attachment of the graphite. Unbonded flats are typically 1/2" thick. Bonded 1/4" graphite to 1/4" steel is specified as 25CG 25CS 50L.Typically the steel plate is 1" larger in both width and length than the graphite for field welding.
This bearing system enables the designer to enjoy the low friction of PTFE at a bearing point temperature above the use limit (500°F) of PTFE. These bearings provide a coefficient of friction less than 3% at a design pressure of 2500 psi (max.) with little variation at lesser pressures.
The bearings can be installed with a stitch weld 1/2 inch long 3 inch on center on all sides. The upper and lower units must be backed up with structural plates so that a uniform load is transmitted into the unit. Bending of the units is unacceptable.