Wire Rope Grease Penetration Information
Is this wire rope penetrated?
High-pressure grease lubricators. This statement implies that grease is injected into the wire rope at high pressure; this is not always the case. Do not be mislead by the pumps high pressure.
Most 50:1 grease pumps have a maximum operating pressure of 5,000 PSI, 345 BAR. This does not mean you have 5,000 PSI in the collar. The reason for the high pump pressure is to force the grease through the hose and fittings. Heavy grease requires a lot of force just to move it; the pump pressure needs to be high for this reason.
CoreLube recommends a pressure gauge be installed at the collar for a very good reason; this is the only way to tell if there is pressure in the collar seal. The pump air regulator pressure gauge will not tell you the pressure in the collar seal.
No penetration can accelerate internal corrosion. Ask any wire rope inspector and they will tell you of wire ropes that look well-greased externally but internally the wire rope is severely corroded.
Rubber type seals do not always reach the bottom of the valleys between the strands of a wire rope. The gaps not filled by the seal will reduce the pressure significantly. All grease collar seals have this problem, especially on larger wire ropes.
Large
Valley
Small
Valley
Contact CoreLube Equipment for more information on wire rope penetration.
US Bureau of Mines Report Summary
As illustrated by the analysis of the strip charts, the thin, synthetic lubricants capable of penetrating the spaces between the wires and into the core are able to extend rope life significantly where internal corrosion and wear are present. By coating the wire surfaces with lubricant, both corrosion and wear can be reduced. The rope does not require an excess of lubricant at one time, but a small amount applied periodically.
The strip charts also show that the heavy, non-penetrating lubricants can cause rapid internal corrosion and deterioration. In some cases, they may even accelerate internal corrosion by promoting the retention of moisture inside the rope.
US Bureau of Mines full report
