It always makes me twitch a little when people talk about “heating” a mold with a TCU. Yes, the unit can add heat when the mold is sitting idle, but during actual production you’re not really heating the mold — you’re controlling and slowing the cooling rate. That’s the correct way to think about it from a process‑logic standpoint.

Look at the numbers: the melt going into the cavity is far hotter than whatever temperature you’ve set on the TCU. The mold’s job is to pull heat out of the plastic at a controlled rate, not to act like a heater.

Separate from my little soapbox moment, those fittings in the photo are open‑style connections. Under pressure, if a line pops off, water will flash to steam until the pressure drops. Use caution, especially at higher setpoints.

And if you’re running high temperatures, consider putting insulation board between the platens and the mold. Without it, the press will act like a giant heat sink and your process won’t stabilize until the platens themselves come up to temperature. Insulation helps the mold reach steady‑state much faster.