Zilmet Cal-Pro Vertical Expansion Vessel - 4 Bar. - 12Ltr Zilmet CAL‑PRO expansion vessels are designed for sealed heating systems to absorb thermal expansion as water temperature increases.

Built for sealed potable hot and chilled water systems in domestic and commercial settings, these Potable Water Expansion Vessels stabilise pressure by absorbing thermal expansion for safe, reliable operation.

A nitrogen pre-charge helps retain set pressure longer, while a single threaded steel connection with plastic insert provides a durable, non-flow-through design. Suitable for central heating, cooling and tap water applications (not for solar collector circuits).

• Nitrogen gas filling for longer pre-charge retention
• Single threaded steel connection with plastic insert (no flow-through)
• Potable use supports domestic hot/chilled water
• Heating & cooling compatible for sealed systems

Designed for long service life with broad operating limits and glycol tolerance for demanding installations.

Purpose-built for solar thermal circuits, the Flexcon Solar 8/2.5 [8Bar] expansion vessel supports sealed systems in line with EN 12828, keeping pressure stable in high-temperature applications.

A preformed butyl rolling diaphragm with extremely low permeability helps retain pre-charge, while a nitrogen fill limits corrosion and pressure loss. The clench ring clamps the diaphragm evenly to prevent damage, and a ribbed profile avoids sticking for instant inflow. An uncoated connection thread aids watertight installation; the steel vessel is finished in a gleaming epoxy-powder coat and factory tested.

• Solar-ready expansion vessel for sealed systems
• Butyl rolling diaphragm with very low permeability
• Nitrogen pre-charge for longer pressure stability
• Clench ring construction for a robust, uniform seal

For 880 Ltrs models: both halves are coated before assembly to protect the clamp ring, and the nitrogen valve is countersunk and covered. Continuous medium temperature range −10 to 110 C.

The MikroPro Expansion Vessels range serves almost any LPHW or CHW system, with capacities from 8500 Ltrs. Models up to 25 Ltrs are wall-mounted, while 35 Ltrs and above are floor-standing. This comes with a wall mount bracket.

With an 12Ltr capacity with an operating pressure of 3 Bar., this is built for performance, reliability and compliance, MikroPro vessels are PED 97/23/EC compliant, rated to a maximum operating temperature of 70 C, and available with pressure ratings of 3 Bar (835 Ltrs) or 6 Bar (501000 Ltrs). Threaded connections and a durable powder-coated finish simplify installation and maintenance.

• Capacities: 8500 Ltrs
• Mounting: wall (≤25 Ltrs) or floor (≥35 Ltrs)
• Ratings: up to 70 C, 36 Bar (model dependent)
• Applications: heating and chilled water systems

A versatile, robust choice for commercial and large domestic systems requiring stable expansion capacity and long service life.

MikroPro Potable XP Expansion Vessel - 12 Litre Capacity - 10 bar. This range serves heating, chilled and potable (drinking) water systems, with capacities up to 500 Ltrs to suit a wide variety of installations for commercial or residential. This item comes without a wall mount bracket.

Built for hygiene and durability, all internal surfaces in contact with water are corrosion-protected for potable use, and models from 50–500 Ltrs feature a replaceable diaphragm for straightforward maintenance.

• Capacity options: 12–500 Ltrs
• Rated pressure: up to 10 Bar
• Potable-safe construction: coated internal wetted surfaces
• Serviceable design: replaceable diaphragm (50–500 Ltrs)

Vessels are PED 97/23/EC compliant, rated to 70 °C, and supplied with threaded connections and a durable powder-coated finish for long service life.

The Refix DD 12 diaphragm expansion vessel is designed for flowed-through operation in domestic hot water systems, water supply installations and pressure-boosting systems.

The Reflex NG 12 diaphragm expansion vessel is designed for sealed heating and cold water systems, providing reliable pressure control in closed-system installations.