Lubrication Injectors — Oil & Grease Metering Devices
each bearing on every pressure cycle. They are the point-level dosing devices in positive-displacement injector (PDI) and single-line grease injector architectures—downstream of the pump and upstream of the friction surface.
IsoHiTech groups injectors into three practical families:
- Oil positive-displacement injectors (PDI) — fixed suffix discharge per cycle at ~0.8–1.5 MPa class; single body or 1–5 outlet manifolds. See DLX single injector and manifold variants on the grid below.
- Grease injector manifolds (SL32) — adjustable steel injectors, NLGI #000–2, 8–24 MPa, 1–12 outlets. Detail: SL32 grease injector.
- Grease manifold blocks (SL1) — higher-volume grease metering blocks with relief valve, 6.5–20 MPa class for demanding single-line grease plants.
Injectors do not replace progressive divider valves—those sequential blocks live on the progressive manifold hub. Pair injectors with positive injector systems, injection lubrication system guides, oil pumps, and grease pumps.
Selection flow: (1) oil vs grease, (2) ml/cycle per point, (3) pressure class, (4) single vs manifold outlet count, (5) pump and controller pairing.
| Pressure | 0.8~1.5Mpa |
| Discharge | 0.1/0.2/0.3/0.4/0.5ml/cyc |
| Thread | M8 or M10 or Pt1/8 |
| Lubricant | Oil |
| Pressure | 0.8~1.5Mpa |
| Discharge | 0.1/0.2/0.3/0.4/0.5ml/cyc |
| Outlets | From 1 to 5 |
| Lubricant | Oil |
| Pressure | 8-24Mpa |
| Discharge | 0.016cc-0.131cc |
| Outlets | 1~12 outlets |
How Injector-Based Lubrication Systems Work
Injector architectures share one main supply line from the pump. On each cycle the controller runs the pump until line pressure rises; every injector on that header that has reached its opening pressure strokes and delivers its dose; then pressure is relieved and injectors recharge. Unlike progressive dividers, injectors on a common line typically act in parallel during the pressure-on phase—not in strict sequence.
- Pump on — grease or oil enters the main header.
- Injectors open — each metered piston discharges to its bearing.
- Pump off / relief — line pressure drops; injectors refill.
- Pause interval — timer waits until the next cycle.
Product Grid at a Glance
| Grid item | Lubricant | Pressure | Discharge | Detail page |
|---|---|---|---|---|
| Single Injector (DLX) | Oil | 0.8–1.5 MPa | 0.1–0.5 ml/cyc | DLX single |
| DLX Manifold | Oil | 0.8–1.5 MPa | 0.1–0.5 ml/cyc × 1–5 outlets | PDI hub |
| SL1 Grease Manifold | Grease NLGI to #2 | 6.5–20 MPa | 0.05–8.2 cc/cyc | — |
| SL32 Manifold | Grease NLGI #000–2 | 8–24 MPa | 0.016–0.131 ml/cyc × 1–12 | SL32 |
Sizing an Injector System
- Sum ml/cycle (or cc/cycle) for all points on one pump circuit.
- Confirm pump reaches opening pressure at the farthest injector.
- Keep secondary lines short; use 4–6 mm tubing and compression fittings.
- Add inline filter on grease fills in dirty environments.
- Run catch tests after any SL32 cap adjustment.
Injectors vs Progressive Dividers
Injectors suit PDI oil plants and single-line grease injector mains where each point needs a defined shot per cycle. Progressive dividers suit one pump feeding a chained block assembly with sequential piston logic. Do not substitute a parallel manifold for a progressive block when equal sequential dosing is required—see grease manifold block vs injector guides.
Installation & Commissioning
- Mount injectors close to lube points; support tubing with pipe clips.
- Install with flow direction toward the bearing (check body marking).
- Prime main line before connecting injector inlets.
- Run three full cycles; verify oil wetting or grease at each point.
- Document part numbers and doses on the machine lube chart.
Troubleshooting
| Symptom | Likely cause | Action |
|---|---|---|
| One point dry | Blocked injector or line | Clear or replace injector; check NPT/M8 runs |
| All points weak | Pump below opening pressure | Check timer, tank level, NLGI grade |
| Over-lubrication | Wrong suffix or cap setting | Downsize DLX suffix; reset SL32 cap |
| Main never builds pressure | Large leak, wrong pump class | Pressure-test header; upsize pump |
Architecture guides: positive injector systems · injection lubrication · injector BOM quote.
Before you buy: read our grease fitting types guide.
A device that delivers a metered shot of oil or grease each time system pressure rises and falls in a cyclic centralized system. It protects bearings by renewing the lubricant film on schedule—not by continuous flow like a restrictor orifice.
The pump pressurizes the main line. When pressure exceeds the injector opening threshold, an internal piston strokes and discharges the set volume to the bearing. When pressure relieves, the injector refills from the supply. Repeat on timer or machine interlock.
DLX-class oil PDIs use fixed discharge suffixes at lower pressure (~0.8–1.5 MPa). SL32 grease injectors use adjustable indicator caps at higher pressure (up to ~24 MPa) with NLGI grease. Choose per lubricant type and OEM manual.
In single-line injector systems, all injectors on a common main receive pressure simultaneously and stroke together when opening pressure is reached. Size pump flow for the sum of all doses per cycle.
SL32 grease manifolds adjust via indicator cap turns. DLX oil injectors select fixed ml/cycle by part-number suffix. Verify with catch tests after any change.
Oil PDI: hand pumps, small electric oil pumps, central stations. Grease injectors: 20703 automatic, FS mobile pumps, and cabinet grease pumps—match pressure and NLGI grade.
Confirm grease or oil at the point after 2–3 cycles, watch indicator pins where fitted, and monitor for pressure buildup on the main line. Blocked injectors often show as one dry point while others still receive lubricant.
Use injectors for PDI/single-line volumetric dosing per point. Use progressive dividers when one pump feeds a sequential block chain. See PDI vs single-line guide.