Quick Answer: Automated lubricant dosing replaces manual greasing with devices that meter small, scheduled amounts of grease to each point. For single hard-to-reach bearings, a single-point automatic lubricator (gas-cell or electromechanical, 30–500 cc) is the right tool. For machines with many grease points, a centralized automatic system with metering valves delivers to every point from one pump. Size the discharge period from bearing dimensions and conditions, and never exceed NLGI #2 — #0/#1 for long lines and cold sites.
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The economics of lubrication failure are lopsided: a missed greasing route costs bearing life; an over-greased bearing blows seals. Automated dosing exists to remove both errors by making delivery small, frequent, and independent of human memory. This guide covers the two architectures — single-point lubricators and centralized dosing systems — and how to size, set, and maintain them.
Two Architectures for Automated Dosing
| Single-Point Lubricator | Centralized Dosing System | |
|---|---|---|
| Covers | One bearing or joint | Dozens to 200+ points from one pump |
| Drive | Gas-generating cell or electromechanical motor | Electric or pneumatic pump + metering valves |
| Reservoir | 30–500 cc cartridge, disposable or refillable | 2–200 kg reservoir |
| Discharge period | Settable, typically 1–12 months per cartridge | Programmable intervals and shot size |
| Best for | Remote, hazardous, or inaccessible single points | Production machines, fleets, multi-point equipment |
The selection question is simply count and access: one stubborn point → single-point unit. A machine full of points → centralized system. Retrofitting a whole machine with single-point units costs more and manages worse than one centralized loop.
Single-Point Lubricators: Gas-Cell vs Electromechanical
Gas-Cell (Hydrogen-Generated Pressure)
A chemical cell generates gas that pushes a piston — no batteries, intrinsically simple, and compact. The trade-offs: discharge rate drifts with temperature (faster when hot, slower in the cold), and most units are disposable. Fine for ambient, accessible-temperature environments with modest precision needs.
Electromechanical (Motor + Piston)
A battery motor drives the piston on a programmed schedule: consistent dosing regardless of temperature, refillable reservoirs, and — on better units — feedback alarms when the cartridge empties or the line blocks. Higher upfront cost, battery changes on the PM list. For critical bearings, the dosing consistency is usually worth it.
IsoHiTech’s single-point range covers both architectures and the classics in between — see the single-point lubricators category, including the automatic single-point lubricator for powered dosing and the spring-loaded single-point lubricator for simple, set-and-forget service. The single-point lubricator overview page walks the full selection.
Sizing the Discharge Period
The cartridge period is arithmetic, not intuition:
- Estimate the bearing’s relubrication quantity and interval from its dimensions, speed, temperature, and environment — our bearing grease calculator returns grams per relube and hours between service directly.
- Divide the cartridge volume by the daily grams to get the period, then set the dispenser dial to the nearest period.
- Verify in the field: after one period, inspect for purge at the seal (over-dosing) or dryness (under-dosing) and adjust one step.
Common sizing errors: setting every dispenser on the machine to the same period regardless of bearing size, and ignoring that gas-cell units speed up in summer heat — a 6-month setting can empty in 4.
Installation Rules That Prevent 90% of Failures
- Keep remote tubing short and fat. Long small-bore lines between the unit and the bearing cause back-pressure that stalls gas-cell units and slows delivery. Mount direct where possible; if remote, keep runs short and use rigid tube or rated hose.
- Respect NLGI limits. Single-point units handle up to NLGI #2, but #0–#1 flows far more reliably in cold weather and long lines. Centralized long-line systems generally require #0/#00 — see our automatic lubrication systems guide.
- Never mix grease families in a refillable unit. Clean the reservoir or dedicate the unit to one grease.
- Prime the line on install. Pre-fill the tubing before connecting so the first dose isn’t weeks away.
- Watch for the silent failures: empty cartridges nobody checked, blocked lines (the unit keeps “working” into a dead end), and wrong-grease refills.
When to Step Up to a Centralized System
Frequently Asked Questions
Are single-point automatic lubricators worth it?
Yes for bearings that are remote, hazardous to reach, or chronically forgotten — the unit costs less than one premature bearing failure. For easily reached points on a disciplined manual route, the payback is weaker. The strongest business case is always access plus criticality.
Gas-cell or electromechanical lubricator — which is better?
Electromechanical for critical bearings and cold sites: dosing stays consistent with temperature and better units alarm on empty or blocked lines. Gas-cell wins on simplicity and price for benign, ambient-temperature installations — just remember its rate drifts with heat and cold.
How do I set the discharge period?
Calculate the bearing’s daily grease need (the bearing grease calculator does this from bore, speed, temperature, and load), divide cartridge volume by daily grams, and set the nearest dial period. Then field-verify after one cycle and adjust — seal purge means too fast, dryness means too slow.
What grease can I use in an automatic lubricator?
Up to NLGI #2 in most single-point units, but NLGI #0–#1 is the reliable choice for cold weather or any remote tubing run. Use quality EP grease matched to the bearing, one grease family per unit, and keep solids modest — high-moly greases can strain fine metering passages.
Why is my automatic lubricator not dispensing?
Work the checklist in order: empty cartridge (most common), blocked or kinked remote line, expired gas cell or dead battery, grease too stiff for the temperature, or a clogged point fitting. A unit that shows no seal purge for a full period is telling you something — investigate, don’t just replace the cartridge.
Need Help Sizing Automated Dosing for Your Machines?
IsoHiTech covers both sides of automated dosing: single-point lubricators for isolated bearings, and centralized systems — pumps, metering valves, dose feeders, and line sets — sized as one package. Send us your point count and bearing list and our engineers will spec the dosing architecture and grease grade to match.
