Metering Unit for SLR Oil Lubrication Systems
In single-line resistive (SLR) oil systems, the pump pressurizes a common supply line. Each bearing or slide receives oil through a metering unit (meter unit) that dispenses a fixed volume per cycle when line pressure rises and then vents when pressure falls. IsoHiTech supplies SBJ series metering units with six standard flow codes—each step doubles the delivered volume.
The lubricator (pump or cyclic valve) delivers oil to a distributor header. Meter units thread into the header or branch tees and outlet to each lubrication point via 4–6 mm lubrication pipe. Correct metering prevents starved ways on CNC machines and over-lubrication that wastes oil and attracts chips.
Flow code logic: SBJ-0 (slow) is the baseline; SBJ-1 through SBJ-5 increase output in steps where each increment doubles flow relative to the prior code. Match the slowest point with SBJ-0 or SBJ-1 and step up on long runs or high-friction zones. Pair with single-line lubrication system design guides and oil pumps sized for total metered demand.
Where Metering Units Fit
- Oil pump — builds line pressure on a timer or controller (lubrication timer)
- Main supply line — nylon or resin tube to distributor
- Distributor / header — splits flow to multiple meter units
- SBJ metering unit — one per lubrication point (or paired points per drawing)
- Secondary line — to bearing, way, chain, or gearbox port
SBJ vs Other Metering Devices
| Device | System | Media | Notes |
|---|---|---|---|
| SBJ meter unit (this page) | SLR oil | Way oil, spindle oil | Resistive orifice + check valve; flow code SBJ-0…5 |
| Single-line injector | SLR / parallel | Oil or grease | Individual injector valve, often higher pressure |
| Progressive manifold block | Progressive grease | NLGI grease | Sequential pistons—not interchangeable with SBJ |
Selection Checklist
- Count lubrication points and assign each an SBJ flow code from OEM ml/cycle spec
- Sum metered volume per pump cycle; verify pump flow exceeds total demand
- Confirm oil viscosity (typically ISO VG 32–68) matches unit rating
- Use 4 mm tube on final legs; 6 mm on longer branches to reduce pressure drop
- Install with arrow toward bearing; do not mount upside down on flooded points
- Parameter
- Product Video
SBJ Series Part Numbers & Flow Codes
| Name | P/N | Flow code | Relative output |
|---|---|---|---|
| SBJ-0 | 33013 | 0 (slow) | Baseline — smallest dose per cycle |
| SBJ-1 | 33014 | 1 | 2× SBJ-0 |
| SBJ-2 | 33015 | 2 (medium fast) | 2× SBJ-1 |
| SBJ-3 | 33016 | 3 (fast) | 2× SBJ-2 |
| SBJ-4 | 33017 | 4 | 2× SBJ-3 |
| SBJ-5 | 33018 | 5 (extra, extra fast) | 2× SBJ-4 — highest standard dose |
Each flow code step doubles metered oil per pressure cycle. Request calibrated flow charts for your oil grade and temperature if auditing an existing CNC way system.
It is a precision valve that releases a controlled volume of oil to one lubrication point each time the supply line is pressurized and depressurized. In SLR systems, SBJ units ensure each bearing gets the right dose without manual adjustment at every point.
When pump pressure rises, internal orifices and check valves allow a metered shot of oil to the bearing. When pressure drops during the pause cycle, the unit resets for the next dose. Flow code (SBJ-0 through SBJ-5) sets orifice size—higher codes pass more oil per cycle.
IsoHiTech stocks six codes from SBJ-0 (slow) to SBJ-5 (extra, extra fast). Each step doubles output. Exact cc per cycle depends on oil viscosity and system pressure—send your point list for a recommended BOM.
Yes, for typical ISO VG 32–68 way and spindle oils within the rated pressure range. Very heavy gear oils or contaminated fluid may require larger codes or filter upgrades upstream.
SLR oil systems commonly run roughly 1–20 bar (0.1–2 MPa) at the distributor, depending on pump and line length. Verify pump relief setting and that the farthest point receives pressure within the meter unit datasheet range.
One SBJ unit typically feeds one lubrication point. A single pump and header can branch to dozens of meters on large machines; total demand must match pump capacity per cycle.
Inspect for blocked outlets, verify check valve function, and confirm flow codes match the lubrication chart after any line repair. Replace units that no longer deliver visible oil shots during manual test cycles.
SBJ meters work with hand-pumped SLR circuits and automatic pumps controlled by a timer. Automatic cycling is standard on CNC way lube packages.
Consistent film thickness, less downtime from dry ways, reduced operator error, and easier auditing than oil cans. Metering units are the repeatable dose element in the architecture.
Start from the machine builder’s ml/cycle table. Use SBJ-0 or SBJ-1 on light points; step up one code for longer tube runs or higher friction. If a point still runs dry, increase code or check for line restrictions—not always pump size.