Reflex - DE 33 Diaphragm Expansion Vessel - 33 Ltr

The Refix DE 33 - 33Ltr diaphragm expansion vessel is designed for water supply installations that are not subject to DIN 1988 requirements, making it suitable for specialist systems such as fire extinguishing installations, service water systems, underfloor heating and heat source applications. Manufactured in accordance with DIN EN 13831 and approved under Pressure Equipment Directive 2014/68/EC, this vessel is built for reliable pressure maintenance in demanding system environments.
No licence requirement according to SWKI HE301-01 and SVTI for (PSV * VN ≤ 3,000 bar * litre).

The vessel features a butyl diaphragm, corrosion-protected water-contact components and a durable epoxy resin coating to support long service life. It is also suitable for systems using antifreeze additives between 25% and 50%, making it a practical option for a wide range of closed-system applications where reliable expansion control is required.

The Refix DE 33 is finished in blue and supplied with mounting brackets. Pressure gauge and supply pressure valve protection is provided by a clip design on applicable variants, while the overall construction is intended to deliver durable and consistent performance in commercial and specialist water system installations.

Key Product Features

• Refix DE 33 non-flowed through diaphragm expansion vessel
• Suitable for water supply installations not subject to DIN 1988
• Ideal for fire extinguishing systems, service water systems, underfloor heating and heat source installations
• Designed and manufactured in accordance with DIN EN 13831
• Approved in line with Pressure Equipment Directive 2014/68/EC
• Butyl diaphragm construction
• Suitable for antifreeze additive concentrations from 25% to 50%
• Parts in contact with water are corrosion-protected
• Durable epoxy resin coating
• Supplied with brackets
• Type: DE 33
• Colour: Blue
• Nominal volume: 33 l
• Maximum useful volume: 23 l
• Minimum operating temperature: -10 °C
• Maximum system temperature: 70 °C
• Maximum operating pressure: 10 Bar
• Factory pre-charge pressure: 4 Bar
• Connection: G 3/4"
• Diameter: 354 mm
• Height: 457 mm
• Tilt dimension approx.: 578 mm
• Weight: 4.92 kg

Reflex (est. 1898) is a German manufacturer of expansion vessels, pressurisation units and system components for heating and cooling networks. Their ranges support HVAC and potable water installations, commonly used in residential and commercial buildings for pressure maintenance, deaeration and system protection.