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.

Purpose-built for EN 12828 heating and chilled-water systems, this multifunction sealed-system unit combines automatic expansion control, pressurisation, deaeration and make-up in a single package.

A pressure-step degassing process—using a controlled pressure drop and patented PALL-ring media—removes dissolved gases even at equilibrium. A replaceable butyl bladder stores the expansion fluid at atmospheric pressure. Supplied with Flexvent Super, height-adjustable feet and a weight-capacity sensor.

• All-in-one functionality — expansion, pressurisation, deaeration and make-up
• Pressure-step deaeration with PALL-ring technology
• Replaceable butyl bladder — easy maintenance and long service life
• Delivered complete — Flexvent Super, adjustable feet, weight-capacity sensor

Designed for commercial, industrial and residential sealed LPHW/CHW installations requiring efficient air removal and stable operating pressures.

Engineered for EN 12828 heating and chilled-water systems, Flamcomat FB Auxiliary Vessels provide additional, pressureless expansion capacity to stabilise sealed system pressures.

Used alongside the Flamcomat FG module, the FB vessel stores expansion fluid at atmospheric pressure inside a replaceable butyl bladder. The wider Flamcomat system employs a pressure-step degassing method with patented PALL-ring media for effective dissolved gas removal. Supplied with Flexvent Super and height-adjustable feet.

• Pressureless auxiliary vessel — increases system expansion volume
• Replaceable butyl bladder for easy maintenance
• Atmospheric storage of expansion fluid inside the bladder

Suitable for systems with a maximum operating temperature of 120 °C (note: additional requirements may apply above 110 °C). Bladder maximum temperature 70 °C.

Flamco Flexcon Expansion Vessel - 110Ltr - 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: 10.0 bar.

Vessels in accordance with EN13831.

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

Minimum/maximum temperature diaphragm: -10 / 90 °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.

Built for sealed heating and chilled-water circuits, the Flexcon M [10Bar] is a replaceable-bladder expansion vessel designed to stabilise system pressure in line with EN 12828.

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

• Replaceable bladder for fast maintenance and long service life
• Delivered ready to install: gauge and adjustable feet included
• Inspection flange for internal access
• Robust steel vessel with durable epoxy-powder finish

Larger Flexcon M models (12008000 Ltrs) can be fitted with a Flexvent Super for enhanced air removal.

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 3 vessel Mainsboost 130 litre vertical steel system with 22 mm connections are installed directly onto the incoming water supply and under mains pressure fills with water. When the chamber is full the pump reaches a state of pressure equilibrium. The Mainsboost system now has a volume of pressurised water ready for distribution throughout the property.

Mains Liquid Boosting Setup

The MAINSBOOST MB 2000SV-1 is intended for 'direct on mains' systems (unvented hot water cylinders and combination boilers) where the incoming mains pressure is greater than 2.5 bar. but the flow is insufficient to meet demand.
MAINSBOOST vessel systems do not require an electrical supply and operate silently.

System cold water storage capacity can be expanded simply by adding one or more MAINSBOOST Add-on pumps as required. 
If the incoming mains water pressure is less than 2.5 bar., a MAINSBOOST Charger pump can be utilised in conjunction with the MAINSBOOST vessel system to boost pressure.

The MAINSBOOST MB 2000SV-1 features a nominal vessel size of 2000 litres and a pressurised cold water water storage capacity of approximately 1100 litres.
Each pump is supplied with a 35mm Upstream Kit (USK) as standard.

Constructed from an epoxy coated steel body and a highly durable virgin butyl diaphragm, all MAINSBOOST vessels are supplied with a 5 year warranty.

Mains Liquid Boosting Setup

The Mainsboost 130 litre vertical steel composite with 22 mm connections is installed directly onto the incoming liquid supply and under mains pressure fills with water. When the chamber is full the pump reaches a state of pressure equilibrium. The Mainsboost system now has a volume of pressurised water ready for distribution throughout the property and where required can be supplied with multiple vessels options. 

The 2 vessel Mainsboost 130 litre vertical composite system with 22 mm connections are installed directly onto the incoming water supply and under mains pressure fills with water. When the chamber is full the pump reaches a state of pressure equilibrium. The Mainsboost system now has a volume of pressurised water ready for distribution throughout the property.

The 3 vessel Mainsboost 130 litre vertical composite system with 22 mm connections are installed directly onto the incoming water supply and under mains pressure fills with water. When the chamber is full the pump reaches a state of pressure equilibrium. The Mainsboost system now has a volume of pressurised water ready for distribution throughout the property.

Mains Liquid Boosting Setup

The MAINSBOOST MB 130SV-1 is intended for 'direct on mains' systems (unvented hot water cylinders and combination boilers) where the incoming mains pressure is greater than 2.5 bar. but the flow is insufficient to meet demand.
MAINSBOOST vessel systems do not require an electrical supply and operate silently.

System cold water storage capacity can be expanded simply by adding one or more MAINSBOOST Add-on pumps as required. 
If the incoming mains water pressure is less than 2.5 bar., a MAINSBOOST Charger pump can be utilised in conjunction with the MAINSBOOST vessel system to boost pressure.

The MAINSBOOST MB 130SV-1 features a nominal vessel size of 130 litres and a pressurised cold water water storage capacity of approximately 72 litres.
Each pump is supplied with the unique compact MAINSBOOST Monobloc 22/28mm Upstream Kit (USK) as standard which significantly simplifies installation.

Constructed from an epoxy coated steel body and a highly durable virgin butyl diaphragm, all MAINSBOOST vessels are supplied with a 5 year warranty.

The 2 vessel Mainsboost 130 litre vertical steel system with 22 mm connections are installed directly onto the incoming water supply and under mains pressure fills with water. When the chamber is full the pump reaches a state of pressure equilibrium. The Mainsboost system now has a volume of pressurised water ready for distribution throughout the property.