What a Metering Unit Does
A metering unit doses one measured shot of oil to one lubrication point on every cycle of a cyclic oil system. It screws into an outlet of a single-line distributor block, and a feed line runs from the unit to the bearing or slide. The system pump pressurizes the line on a timed cycle; see our lubrication oil pump overview for that side of the system.
In SLR single-line oil systems, oil metering at every lubrication point comes down to this unit: pick the SBJ flow code, and each point gets its fixed dose per cycle.
How It Is Built
Three parts share one body. A fixed orifice sets the dose rate, a movable pin meters and then shuts off the shot, and a check valve keeps oil from draining back between cycles. When line pressure rises, the pin lifts and the measured shot travels down the feed line.
Flow Codes and the Ordering Table
Each unit carries a stamped flow code and a flow-direction arrow; install it with the arrow pointing toward the bearing. Codes run from 3/0, the slowest, up to 5, the fastest. The SBJ ordering codes map to the stamped codes like this:
| Ordering code | Stamped flow code |
|---|---|
| SBJ-0 | 3/0 |
| SBJ-1 | 1 |
| SBJ-2 | 2 |
| SBJ-3 | 3 |
| SBJ-4 | 4 |
| SBJ-5 | 5 |
The part-number range 33013-33018 covers SBJ-0 through SBJ-5.
Metering Unit vs Control Device
A metering unit belongs to cyclic systems and includes a check valve. A control device uses a helical passage, has no check valve, and meters oil continuously in continuous systems. The two are not interchangeable: fitting a control device where a metering unit belongs leaves points undosed between cycles, which is the classic mis-order on these systems.
Selecting and Installing
One unit serves one point on one line, and splitting a unit’s output between two bearings starves both. Select the code by bearing size, load, and cycle frequency, and resist oversizing because too large a code dumps excess oil at the point. Filter the oil and flush the lines before start-up, because the orifice is small and clogs easily.
Where They Run
Metering units run on construction machinery, machine tools, material handling equipment, food processing and packaging lines, and wind power equipment. Upstream, the distributor block splits one pump feed into many lines; downstream, oil reaches the point or a spray nozzle where the line ends in a spray system. Drip oilers cover points that need a steady gravity feed instead of cycling, and the automatic lubrication overview ties the whole layout together. For a full system build, contact us for a quote with your bearing list and cycle plan.
Frequently Asked Questions
What is a metering unit?
A dosing element that delivers one measured oil shot to one point on every system cycle. It sits between the distributor block and the bearing line.
How is it different from a control device?
A metering unit has a check valve and belongs to cyclic systems. A control device has a helical passage, no check valve, and serves continuous systems.
What do the flow codes mean?
The stamped code rates the dose: 3/0 is the slowest and 5 the fastest. The arrow on the body must point toward the bearing.
How do I pick a flow code?
Match the code to bearing size, load, and cycle frequency. Do not oversize, because too large a code dumps excess oil at the point.
Which direction does it install?
With the stamped flow arrow pointing toward the bearing. Reversed, the check valve blocks the shot.
What are the SBJ codes?
SBJ-0 through SBJ-5 are ordering codes mapped to stamped codes 3/0 through 5. Part numbers 33013-33018 cover the range.
Can one unit feed two bearings?
One unit can feed only one point. Splitting output starves both bearings, so split upstream at the distributor block instead.
What happens if the oil is dirty?
The small orifice clogs and the point stops receiving oil. Filter the oil and flush lines before start-up.
How do I order a set?
Send your bearing list and cycle plan, then ask our team to map points to codes. Contact our team for a quote and we reply with a full dosing schedule.
Who builds these metering units?
IsoHiTech Lubrication Systems, founded in 2023, engineering since 2006, builds and supports every unit. Email inquiry@isohitech.com for specifications and a quotation.
