Zilmet Cal-Pro Vertical Expansion Vessel - 6 Bar. - 300Ltr Zilmet CAL‑PRO expansion vessels are designed for sealed heating systems to absorb thermal expansion as water temperature increases.

Built for sealed heating (EN 12828) and chilled-water systems, Flexcon Premium Expansion Vessels stabilise system pressure by absorbing thermal expansion so plant runs safely and efficiently.

A new TPO (thermoplastic polyolefin) diaphragm on 1235 Ltrs models delivers high flexibility and extremely low permeability, helping the pre-charge hold for longer. Lighter construction cuts material use and transport emissions; packaging is FSC-certified to reduce CO₂ impact.

• Sustainable design lighter TPO membrane uses up to 50% less material
• Long service life 15-year warranty
• Low permeability pre-charge pressure maintained for longer
• Heating & cooling suitable for LPHW and CHW installations

Vessels comply with EN 13831 and the Pressure Equipment Directive 2014/68/EU. Red epoxy powder coating (RAL 3002). Flexcon Premium 3580 are supplied with feet and a mounting kit.

The HeatWave Vessel - Vertical - 100Ltr is a Pressure Vessel item.

The HeatWave™ series hydronic expansion tanks provide quality protection for closed loop hydronic heating systems from excessive pressure due to thermal expansion.

Easy to install and featuring an incorporated hex nut connection, HeatWave™ tanks feature an air chamber sealed with a brass air valve and O-ring sealed air cap.  developed to be supported by either system piping, wall-mounted bracket (inline models) or be freestanding (vertical model with base), the HeatWave™ has a maximum working temperature of 99° C / 210° F .

The operating pressure of this is 6 bar.

• Diaphragm design
• Patented Stainless Steel (vertical models) or chromed steel (inline models) water connection

• Two-part polyurethane, epoxy primed paint finish
• Leak-free, O-ring sealed air valve cap
• Maintenance Free

The HeatWave Vessel - Inline - 12Ltr is a Pressure Vessel item.

The HeatWave™ series hydronic expansion tanks provide quality protection for closed loop hydronic heating systems from excessive pressure due to thermal expansion.

Easy to install and featuring an incorporated hex nut connection, HeatWave™ tanks feature an air chamber sealed with a brass air valve and O-ring sealed air cap.  developed to be supported by either system piping, wall-mounted bracket (inline models) or be freestanding (vertical model with base), the HeatWave™ has a maximum working temperature of 99° C / 210° F .

The operating pressure of this is 6 bar.

• Diaphragm design
• Patented Stainless Steel (vertical models) or chromed steel (inline models) water connection

• Two-part polyurethane, epoxy primed paint finish
• Leak-free, O-ring sealed air valve cap
• Maintenance Free

The HeatWave Vessel - Vertical - 150Ltr is a Pressure Vessel item.

The HeatWave™ series hydronic expansion tanks provide quality protection for closed loop hydronic heating systems from excessive pressure due to thermal expansion.

Easy to install and featuring an incorporated hex nut connection, HeatWave™ tanks feature an air chamber sealed with a brass air valve and O-ring sealed air cap.  developed to be supported by either system piping, wall-mounted bracket (inline models) or be freestanding (vertical model with base), the HeatWave™ has a maximum working temperature of 99° C / 210° F .

The operating pressure of this is 6 bar.

• Diaphragm design
• Patented Stainless Steel (vertical models) or chromed steel (inline models) water connection

• Two-part polyurethane, epoxy primed paint finish
• Leak-free, O-ring sealed air valve cap
• Maintenance Free

The HeatWave Vessel - Inline - 18Ltr is a Pressure Vessel item.

The HeatWave™ series hydronic expansion tanks provide quality protection for closed loop hydronic heating systems from excessive pressure due to thermal expansion.

Easy to install and featuring an incorporated hex nut connection, HeatWave™ tanks feature an air chamber sealed with a brass air valve and O-ring sealed air cap.  developed to be supported by either system piping, wall-mounted bracket (inline models) or be freestanding (vertical model with base), the HeatWave™ has a maximum working temperature of 99° C / 210° F .

The operating pressure of this is 6 bar.

• Diaphragm design
• Patented Stainless Steel (vertical models) or chromed steel (inline models) water connection

• Two-part polyurethane, epoxy primed paint finish
• Leak-free, O-ring sealed air valve cap
• Maintenance Free

The HeatWave Vessel - Inline - 24Ltr is a Pressure Vessel item.

The HeatWave™ series hydronic expansion tanks provide quality protection for closed loop hydronic heating systems from excessive pressure due to thermal expansion.

Easy to install and featuring an incorporated hex nut connection, HeatWave™ tanks feature an air chamber sealed with a brass air valve and O-ring sealed air cap.  developed to be supported by either system piping, wall-mounted bracket (inline models) or be freestanding (vertical model with base), the HeatWave™ has a maximum working temperature of 99° C / 210° F .

The operating pressure of this is 6 bar.

• Diaphragm design
• Patented Stainless Steel (vertical models) or chromed steel (inline models) water connection

• Two-part polyurethane, epoxy primed paint finish
• Leak-free, O-ring sealed air valve cap
• Maintenance Free

The HeatWave Vessel - Inline - 2Ltr is a Pressure Vessel item.

The HeatWave™ series hydronic expansion tanks provide quality protection for closed loop hydronic heating systems from excessive pressure due to thermal expansion.

Easy to install and featuring an incorporated hex nut connection, HeatWave™ tanks feature an air chamber sealed with a brass air valve and O-ring sealed air cap.  developed to be supported by either system piping, wall-mounted bracket (inline models) or be freestanding (vertical model with base), the HeatWave™ has a maximum working temperature of 99° C / 210° F .

The operating pressure of this is 6 bar.

• Diaphragm design
• Patented Stainless Steel (vertical models) or chromed steel (inline models) water connection

• Two-part polyurethane, epoxy primed paint finish
• Leak-free, O-ring sealed air valve cap
• Maintenance Free

The HeatWave Vessel - Inline - 35Ltr is a Pressure Vessel item.

The HeatWave™ series hydronic expansion tanks provide quality protection for closed loop hydronic heating systems from excessive pressure due to thermal expansion.

Easy to install and featuring an incorporated hex nut connection, HeatWave™ tanks feature an air chamber sealed with a brass air valve and O-ring sealed air cap.  developed to be supported by either system piping, wall-mounted bracket (inline models) or be freestanding (vertical model with base), the HeatWave™ has a maximum working temperature of 99° C / 210° F .

The operating pressure of this is 6 bar.

• Diaphragm design
• Patented Stainless Steel (vertical models) or chromed steel (inline models) water connection

• Two-part polyurethane, epoxy primed paint finish
• Leak-free, O-ring sealed air valve cap
• Maintenance Free

The HeatWave Vessel - Inline - 4Ltr is a Pressure Vessel item.

The HeatWave™ series hydronic expansion tanks provide quality protection for closed loop hydronic heating systems from excessive pressure due to thermal expansion.

Easy to install and featuring an incorporated hex nut connection, HeatWave™ tanks feature an air chamber sealed with a brass air valve and O-ring sealed air cap.  developed to be supported by either system piping, wall-mounted bracket (inline models) or be freestanding (vertical model with base), the HeatWave™ has a maximum working temperature of 99° C / 210° F .

The operating pressure of this is 6 bar.

• Diaphragm design
• Patented Stainless Steel (vertical models) or chromed steel (inline models) water connection

• Two-part polyurethane, epoxy primed paint finish
• Leak-free, O-ring sealed air valve cap
• Maintenance Free

The HeatWave Vessel - Vertical - 60Ltr is a Pressure Vessel item.

The HeatWave™ series hydronic expansion tanks provide quality protection for closed loop hydronic heating systems from excessive pressure due to thermal expansion.

Easy to install and featuring an incorporated hex nut connection, HeatWave™ tanks feature an air chamber sealed with a brass air valve and O-ring sealed air cap.  developed to be supported by either system piping, wall-mounted bracket (inline models) or be freestanding (vertical model with base), the HeatWave™ has a maximum working temperature of 99° C / 210° F .

The operating pressure of this is 6 bar.

• Diaphragm design
• Patented Stainless Steel (vertical models) or chromed steel (inline models) water connection

• Two-part polyurethane, epoxy primed paint finish
• Leak-free, O-ring sealed air valve cap
• Maintenance Free

The HeatWave Vessel - Vertical - 80Ltr is a Pressure Vessel item.

The HeatWave™ series hydronic expansion tanks provide quality protection for closed loop hydronic heating systems from excessive pressure due to thermal expansion.

Easy to install and featuring an incorporated hex nut connection, HeatWave™ tanks feature an air chamber sealed with a brass air valve and O-ring sealed air cap.  developed to be supported by either system piping, wall-mounted bracket (inline models) or be freestanding (vertical model with base), the HeatWave™ has a maximum working temperature of 99° C / 210° F .

The operating pressure of this is 6 bar.

• Diaphragm design
• Patented Stainless Steel (vertical models) or chromed steel (inline models) water connection

• Two-part polyurethane, epoxy primed paint finish
• Leak-free, O-ring sealed air valve cap
• Maintenance Free

The HeatWave Vessel - Inline - 8Ltr is a Pressure Vessel item.

The HeatWave™ series hydronic expansion tanks provide quality protection for closed loop hydronic heating systems from excessive pressure due to thermal expansion.

Easy to install and featuring an incorporated hex nut connection, HeatWave™ tanks feature an air chamber sealed with a brass air valve and O-ring sealed air cap.  developed to be supported by either system piping, wall-mounted bracket (inline models) or be freestanding (vertical model with base), the HeatWave™ has a maximum working temperature of 99° C / 210° F .

The operating pressure of this is 6 bar.

• Diaphragm design
• Patented Stainless Steel (vertical models) or chromed steel (inline models) water connection

• Two-part polyurethane, epoxy primed paint finish
• Leak-free, O-ring sealed air valve cap
• Maintenance Free

Flamco Flexcon Expansion Vessel - 1000Ltr - Engineered for EN 12828 heating and chilled-water systems, this Expansion Vessel stabilises sealed system pressure by absorbing thermal expansion in LPHW/CHW applications.

Maximum working pressure: 6.0 bar.

Vessels in accordance with EN13831.

Suitable for systems with a maximum system temperature of 120 °C.

Minimum / maximum temperature diaphragm: -10 / 70 °C.

Suitable for addition of glycol-based anti-freeze up to 50%.

A flexible rolling diaphragm with a ribbed profile prevents sticking and encourages inflow at the slightest pressure rise, while a nitrogen pre-charge helps maintain set pressure longer. The uncoated connection thread supports quick, watertight installation.

• Rolling-diaphragm design for smooth expansion control
• Nitrogen pre-charge for extended pre-pressure retention
• Top-quality steel with epoxy-powder finish
• Factory tested for reliability

Built for long service life in domestic, commercial and industrial plant rooms, with continuous medium temperatures from −10 to 70 C.

Flamco Flexcon M Expansion Vessel - 100Ltr - 3-6 bar. - Tailored for sealed heating and chilled-water systems, the Flexcon M 100/3.0 [6Bar] is a replaceable-bladder expansion vessel designed to stabilise pressure in accordance with EN 12828.

It excels where static pressure and safety-valve setpoint differ significantly, helping maintain pre-pressure while minimising cycling. Supplied ready to install with a pressure gauge and height-adjustable feet, plus an inspection flange for servicing.

• Replaceable butyl bladder for fast maintenance
• Pressure gauge and height-adjustable feet included
• Inspection flange for internal access
• Robust steel vessel with durable epoxy-powder finish
• Uncoated connection thread for easy, watertight installation

For larger models (12008000 Ltrs), a Flexvent Super can be fitted to enhance air removal.

Flamco Flexcon M Expansion Vessel - 200Ltr - 3-6 bar. - Tailored for sealed heating and chilled-water systems, the Flexcon M 100/3.0 [6Bar] is a replaceable-bladder expansion vessel designed to stabilise pressure in accordance with EN 12828.

It excels where static pressure and safety-valve setpoint differ significantly, helping maintain pre-pressure while minimising cycling. Supplied ready to install with a pressure gauge and height-adjustable feet, plus an inspection flange for servicing.

• Replaceable butyl bladder for fast maintenance
• Pressure gauge and height-adjustable feet included
• Inspection flange for internal access
• Robust steel vessel with durable epoxy-powder finish
• Uncoated connection thread for easy, watertight installation

For larger models (12008000 Ltrs), a Flexvent Super can be fitted to enhance air removal.