Every graphite ring we machine starts as a grey block — and ends up keeping a pump running

Every finished ring in this post started as a grey block — raw carbon graphite blanks stacked on shelves and in piles, waiting for their turn on the lathe. Machining graphite is its own craft: it cuts differently from metal, it is brittle, and it dusts everything around it. Turning the bore, cutting the grooves, drilling the bolt circles, splitting a solid ring into segments — all of it happens in our own workshop, on our own machines.

The last frames show what comes off the bench: graphite rings and sleeves in a wide range of diameters, some with fine grooves machined into the bore, some split into segments, some machined to a smooth matte finish. Carbon graphite is self-lubricating, which is why it keeps showing up in pumps and rotating equipment wherever the liquid film runs thin — it keeps doing its job when lubrication does not.

Graphite runs through almost everything we build at Lepu — the faces inside a mechanical seal for centrifugal pump and mechanical seal for water pump duty, the bushings in mechanical pump shaft seals, and the graphite rings we cut as mechanical seal replacement parts for equipment already in service. We are a manufacturer of mechanical seals for rotating equipment, and we take on OEM replacement mechanical seals and OEM pump mechanical seals from a drawing, a sample, or a used part. Send it over — we will match it.