How many meter units can an L5P run?
Short answer, from Bijur data sheet 21967: up to 70 Type F meter units, at a discharge pressure of up to 75 psi. A Bridgeport uses 8 to 10, so the count is never the problem on a knee mill. The real limit is how much total flow the pump can push per stroke.
The stroke setting. The L5P delivers 1 to 5 cc per push, set by the stroke screw under the handle (1" of stroke = 1 cc, 1-1/8" = 2 cc, 1-1/4" = 3 cc, 1-3/8" = 4 cc, 1-1/2" = 5 cc). It leaves the factory at 5 cc.
The flow table. Every meter unit has a flow rating (0, 1, 2 …; each step doubles the flow). Add up the flow value of all the units on the pump and that total must stay under the number in BDI's table for your stroke and unit count:
| Meter units on the pump | 1 cc | 2 cc | 3 cc | 4 cc | 5 cc |
|---|---|---|---|---|---|
| 5 | 240 | 450 | 700 | 800 | — |
| 10 | 170 | 320 | 550 | 680 | 750 |
| 15 | 140 | 250 | 440 | 520 | 650 |
| 20 | 115 | 210 | 360 | 460 | 520 |
| 25 | 100 | 180 | 320 | 400 | 450 |
| 30 | 85 | 150 | 275 | 325 | 390 |
| 40 | 60 | 120 | 210 | 245 | 290 |
| 50 | 57 | — | — | — | 90 |
| 60 | — | — | — | — | 60 |
(Maximum permissible total system flow, ø, per data sheet 21967. The flow value of each rate number comes from Bijur Brochure B262 / Manual 258; send us your unit list and we will do the sum.)
What this means on a Bridgeport. Ten units of rate 0 and 1 at the factory 5 cc stroke are far inside the table. If you have added points (a power feed, a quill lube, a rotary table) and the last ones on the line run dry, the fix is usually to leave the stroke at 5 cc and pump twice, or to step the starving unit up one rate number, not to buy a bigger pump.
Other rules from the same sheet. Oil 150–8,000 SSU (ISO 68 way oil is right in the middle). The inlet filter is 40 micron: inspect every six months, replace the filter group (S109) yearly. Discharge pressure falls as you add meter units and as you turn the stroke down, so a system with many units on a 1 cc stroke may not open the 5 lb check valves at the far end; that shows as dry points, and the answer is more stroke.
→ Bridgeport / Knee Mill Kit — L5P-R with tubing kit, 10 meter units and fittings — $856 · L5P-L $870 · L5P-R pump only $456.76. Questions: sales@ldewitt.net or (210) 494-1997.