Grease pipe diameter

[APmmore]

Is there any calculation to arrive at the optimum pipe inner diameter for having comfortable passage of grease through it.

Guess it will be a function of NLGI, length & pipe material.

This to extend greasing points away from the bearings for much comfort, but the pipe selection should also support the grease as well as it should pass properly.

 

[bimr]

Grease lines are usually 6mm or 1/4".

Bearing manufacturers recommend the amount of grease to apply to a bearing by weight or volume. In practice, the amount of grease applied to a bearing is often determined by the number of shots from the grease gun. Generally, operating conditions will dictate the re-lubrication interval required.

http://www.timken.com/en-us/products/Documents/Timken-Engineering-Manual.pdf

Common zerk grease fittings are 1/4-28 UNF tapered thread, the metrics are M6.

 

[racookpe1978]

Grease doesn't "flow" through the grease fittings then pipe run, then into the bearing gap. It "gets squirted" by a high pressure gun at very irregular times in irregular pulses - think of it more like a positive displacement pump (the grease gun) forcing the grease into that tiny squeegeed out bearing/gear gap through the very, very tiny gap between the grease insert ball bearing and the ball bearing tip.

SO, as long as the 1/4 inch/6 mm tube isn't completely blocked, the guy greasing things is expected to keep squeezing until the grease comes out the bearing.

So it's more important to see the bearing edge while pumping than changing the size of the grease tubing.