Lubrication Fittings, Tubing & Accessories

A centralised lubrication circuit is a main line branching down to each point, and the fittings are what make the branches. PA, PB and PT fittings tap a branch off a Ø4 or Ø6 main line to reach one lubrication point. PL elbows take a 90° turn where the tube can't be bent into a tight point (a common need inside a crowded electrical cabinet or close to a moving axis). PD in-line unions extend a run or adapt into a distributor outlet, and the range includes the PD35612 and PD35812 adapters the 35 Type distributor specifically needs. 3T and 4T brass manifolds split one main line into three or four branch lines from a single point, all on M10×1 threads throughout the family.

When an outlet on a manifold or distributor isn't in use, it still needs to be sealed rather than left open. That's what the PS-08Z and PS-10Z blanking dummies are for. An open outlet on a pressurised line doesn't fail loudly; it just quietly starves every other point on the circuit of pressure.

Tube for these circuits comes in nylon (Ø4, Ø6 or Ø8) and copper (Ø4 or Ø6). As general engineering guidance, nylon is the more common choice for routing flexibility on runs that bend around a machine's structure, while copper is rigid and better suited to runs near heat sources where a plastic tube would degrade over time. Check your machine builder's original routing before substituting one material for the other on an existing circuit. Whichever material is used, cut it square with a matched tube cutter rather than a side-cutter or knife: a burred cut is one of the more common causes of a blocked lubrication point, because the burr sits exactly where the tube seats into the fitting.

Diameter follows the port it's feeding: match Ø4 or Ø6 tube to a PA/PB/PT branch fitting sized for it, and confirm the distributor or manifold port size before ordering tube for a new run rather than after.

A pressure switch (5 or 10 kgf/cm² set points) and a 0–4 MPa gauge both tell you about line pressure, but they serve different jobs. The switch is what you wire into a machine's PLC or a pump's own timer circuit, so the control system gets a pass/fail signal automatically. The gauge is what you read by eye: the fastest way, at commissioning or during troubleshooting, to tell a blocked lubrication point from a pump that has simply stopped. A sight-type level indicator does the equivalent job for the reservoir: it shows oil level from outside the cabinet, without opening the tank to workshop dust every time someone wants to check it.

For occasional top-up of a single pump reservoir or a hand-packed bearing, a grease gun is the straightforward tool. Where several machines on a shop floor all need refilling on a schedule, the motorised barrel replenish unit does the same job from a bulk barrel without opening each individual tank to airborne dust (a detail that matters more than it sounds, since grit in a reservoir is a direct cause of a jammed distributor downstream).