Constant feed line oilers deliver a steady, metered flow of oil into the air line drop by drop through an adjustable needle valve rather than the burst-style delivery of pressure-feed oilers. Aluminum-bodied reservoirs run from 1 quart to 12 gallons with threaded connections from 1-1/4 in. to 3 in., making them the oiler of choice for down-the-hole hammers and other air tools that consume oil volume over long service.

A borosilicate or acrylic sight glass shows the level, a pressure relief cap safely vents the reservoir before refilling, and mounting threads put the oiler right in the line; the largest sizes keep a DTH string oiled through a full shift. Compare capacities across our hose oilers, pair the reservoir with rock drill oil in the right viscosity, and see the DTH hammer buyers guide for hammer selection.

• Reservoir sizes from 1 quart to 12 gallons with lightweight aluminum body and base
• Threaded connections from 1-1/4 in. through 3 in.
• Adjustable needle valve meters a continuous, drop-by-drop oil feed
• Sight glass for level checks; pressure relief cap vents air pressure safely before refills
• Best suited to DTH drilling and air tools needing oil volume over long service
• Stocked by Crowder Supply in Denver

Constant Feed Line Oiler FAQ

What is the difference between a constant feed oiler and a standard in-line lubricator?
A constant feed oiler meters oil continuously, drop by drop, through an adjustable needle valve, with reservoirs up to 12 gallons for long service. A compact in-line lubricator is the usual choice for a single handheld tool with a smaller oil appetite.

What size reservoir do I need?
Sizes run from 1 quart to 12 gallons. Down-the-hole drilling consumes the most oil, so DTH strings typically run the larger reservoirs to stay lubricated through a full shift.

How do I refill it safely?
Use the pressure relief cap to vent air pressure from the reservoir before opening it; the sight glass shows the oil level so refills can be timed before the reservoir runs dry.