Lubrication or hydraulics: the first sort
In lubricant dispensing, the reel feeds a metered gun from a drum or tank, via a pneumatic pump. Pressure stays moderate and the critical point is viscosity: a thick oil in a hose that is too thin turns the pump into a brake.
In hydraulics, the reel carries a fluid under high pressure to a tool or a cylinder. Everything then rests on the pressure rating of the assembly and on the quality of the swivel joint, which endures pressure and rotation simultaneously.
Viscosity, diameter, temperature
The viscosity of an oil varies strongly with temperature: an oil that flows freely in a heated workshop turns pasty in an unheated room in winter, and the flow collapses. That is why the diameter is oversized in lubricant dispensing rather than raising the pump pressure — the latter wears the equipment without solving the problem.
In practice, Ø 1/2″ covers most lubrication stations; Ø 3/8″ is enough in hydraulics, where pressure compensates for the reduced cross-section.
The seals decide compatibility
Conventional mineral oils are happy with NBR, standard and economical. Synthetic oils, some fire-resistant hydraulic fluids and high temperatures require Viton or PTFE. An incompatible seal does not show immediately: it swells, hardens, then leaks after a few months.
For food-grade oils, stainless steel and suitable seals become the rule, for reasons of hygiene as much as compatibility.
Floor marking, the criterion discovered too late
A standard hydraulic hose has a black cover loaded with carbon black. Unwound and dragged several times a day over a painted floor, workshop tiles or a light-coloured resin, it leaves a grey mark that cleaning does not remove. The defect only appears after several weeks, when the damage is done.
The criterion exists and takes one sentence to ask: is the hose non-marking? Few manufacturers offer it in their catalogue, so it must be checked before ordering rather than hoped for. At Zeca, references 8446 and 8448 of the 8400 series use the 10 mm 1SC hose at 180 bar in a blue non-marking version, in 15 and 18 metres.
The rest of the series covers oil from 160 to 400 bar depending on the hose fitted. On high pressures and pressure-rating questions, see also the grease reels page.