Pressurized water: direct cooling (WDC) and indirect cooling (WIC)
Above 90 °C, water needs pressure to remain liquid. The pressurized range reaches up to 180 °C in two families depending on how they cool: WDC (direct, aggressive cooling) and WIC (indirect, precise control and highest temperature).
By pressurizing the circuit, the water remains liquid above 100 °C. There are two families depending on the refrigeration: WDC (direct) —injection, aggressive cooling and low temperatures, up to 140 °C— and WIC (indirect) —by exchanger, precise and stable control, up to 180 °C—.
Why is pressurize the water
At atmospheric pressure, water boils at 100 °C, and upon boiling it is no longer a stable thermal fluid: steam bubbles appear, the flow rate becomes irregular and the transfer rate drops.
The circuit is closed and pressurized, so water remains liquid well above 100 °C. The higher the set temperature, the greater the pressure the circuit needs to keep it liquid. From there, what distinguishes the two families is how does it cool.
WDC y WIC: how do they cool makes the difference
- Aggressive and rapid cooling
- Reaches low working temperatures (≈20–40 °C)
- Up to 140 °C (90/120/140 versions)
- The cooling water enters the circuit (it should be clean)
- Fine and stable control of the setpoint
- Isolated process circuit
- The highest temperature family: up to 180 °C
- For precision, stability and high temperatures
Both are pressurized water and share the same SMART control system; The choice depends on whether the process prioritizes cooling power / low temperatures (WDC) or stability and high temperatures (WIC).
How to achieve the high temperatures
The higher the setpoint, the more pressure is needed to keep the water liquid, and the pump goes from high flow to high pressure. Rule of thumb: at a higher temperature, more pressure and less flow.
From 140 °C (≈200 l/min at 2.3 bar) you move on to higher pressure pumps—up to 6 bar— at 150–180 °C. above 150 °C mounted magnetic pump (without mechanical seal); the model of 180 °C duck booster and electronic flow measurement.
Why do we set the water limit at 180°C?
Above 180°C pressurized water is still technically possible – some manufacturers take it further – but the equipment crosses a boundary: each additional degree raises the pressure, safety requirements and maintenance. These are the terms:
In Marse we choose not to cross that threshold with water. We set the pressurized water limit at 180 °C —the point where the equipment remains safe, reliable and reasonably maintained—and, above, we move on to oil technologies, which reach those temperatures without those pressures or those demands. In all our technologies, the equipment is delivered with CE marked and in accordance with applicable regulations, faithful to Marse's work principles: safety, reliability and quality.
What model exists each temperature
| Parameter | 140 °C | 150 °C | 160 °C | 180 °C |
|---|---|---|---|---|
| Models | 2 / 4 / 6 plus | 2 / 4 plus | 2 / 4 plus | 2 plus |
| Heating | 9 – 64 kW | 9 / 16 kW | 9 / 16 kW | 9 kW |
| Pump flow | 200 / 250 l/min | 40 / 60 l/min | 60 l/min | 60 l/min |
| Max pressure bomb | 2,3 – 3,5 bar | 5 / 6 bar | 6 bar | 6 bar |
| Pump type | Centrifuge (magnetic optional) | Magnetic | Magnetic | Magnetic + booster |
WDC is offered in 90, 120 and 140 °C versions (3 models, 9–64 kW, pump 200–250 l/min). At these temperatures, the water quality of the circuit causes limescale and corrosion.
What they share all models
Two control systems: Display (TG121) o TouchScreen (TG111, 7"). The TouchScreen adds pressure reading by transducer, external probe as a control variable, heating ramp, recipes and remote control/monitoring.
Pressurized water for your temperature range
Tell us your temperature, power and flow and the configurator sizes the appropriate WDC or WIC equipment.
The pressurized range of the SMART Series
Pressurized Water Direct (WDC) — aggressive cooling and low working temperatures, up to 140 °C (SMART 2, 4 and 6 plus WDC models). Indirect pressurized water (WIC) — precise and stable control, up to 180 °C (SMART 2, 4 and 6 plus WIC models).
Both: 9–64 kW, stainless steel construction, automatic filling, Display (TG121) or TouchScreen (TG111) control. Above 180 °C, the range has oil technologies (open tank up to 150 °C and closed circuit up to 300 °C).
Common questions
What is the difference between WDC and WIC?
The cooling method. WDC cools directly (injects cooling water into the circuit): aggressive cooling and low working temperatures, up to 140 °C. WIC cools indirectly (via exchanger, without mixing): precise and stable control, up to 180 °C.
What temperature does pressurized water reach?
Up to 180 °C, with the WIC family (140/150/160/180 °C versions). WDC covers up to 140°C.
Why do we use a magnetic pump after 150 °C?
Because the centrifugal pump depends on a mechanical seal on the shaft, and at high temperatures that seal is the weak point. The magnetic pump dispenses with a mechanical seal—no leak point on the shaft—which translates into less maintenance, in exchange for a higher cost. That's why it's standard above 150°C and optional below.
When is WDC and when is WIC appropriate?
WDC when the process needs strong and fast cooling or low setpoints (fast cycles, low mold temperature). WIC when you prioritize stability and precision, or temperatures of 150–180°C with water.
Is the cooling water mixed with the process water?
In WDC yes: the cooling is by direct injection, so the cooling water becomes part of the circuit (it should be clean). Not in WIC: it is cooled by an exchanger and the process circuit is isolated.