Reflex Winkelmann GmbH is considered one of the leading solutions providers for the smooth operation of water-based systems in the building services sector and is increasingly becoming the preferred choice for pressure maintenance and degassing solutions for systems requiring a high level of resilience.

This success has been established over the past 50+ years in the pressure maintenance market, adapting to changing market requirements and customer expectations in the global services sector.  

Taking this into account, Reflex Winkelmann GmbH strives to provide user friendly, flexible and robust solutions which system design engineers, installers and maintenance companies recognise. Considered the ‘lung’ of a sealed system, the correct selection of pressure maintenance equipment is essential for smooth operation and must demonstrate reliability and resilience (N+1) in critical systems such as data centre cooling applications. 

When larger systems are being considered (+2 MW of cooling), it is generally agreed that dynamic pressure maintenance solutions are preferred over traditional ‘static’ expansion vessels, and this is where Reflex has excelled.

Over time, the Reflex dynamic pressure maintenance solution has evolved, resulting in the current range and, applying the principle of flexible design, can tailor the solution depending on specific system requirements.

Using a patented method of control, the Reflex ‘Variomat’ range of dynamic pressure maintenance design can maintain system pressure to +/- 0.2 Bar regardless of the system status. This is achieved by the ‘Control Touch’ controller modulating multi-stage pumps and self-cleaning motorised ball valves resulting in incredibly accurate pressure maintenance.

When pressure maintenance in critical systems (e.g. data centres) is being considered, reliability and resilience is paramount. As previously mentioned, the Variomat range has evolved over the years into an incredibly reliable solution using the best quality materials of construction, including duty/standby or duty/assist multi-stage pump and self-cleaning motorised ball valves preferred over solenoid valves, minimising the risk of failure. 

To give the system further integrity, software within the Control Touch module can be easily configured to be linked to other Reflex Variomat modules via master/slave (N+1) with capabilities of linking up to 10 separate units as master/slave, resulting in stable operation without multiple units conflicting with each other.

When addressing the control protocols, a variety of options are requested depending on the specific requirements of the installation and, as these are modular units, almost all protocols can be accommodated. These range from simple volt free contacts (I/O module) to BACnet and Modbus options available, to name a few. This permits remote ‘real-time’ system monitoring and flags any warnings before systems go into full alarm condition. Looking into the future, additional BMS protocols could be considered without the need for product redesign.

Moving onto the storage of expanded water, the Variomat (and Giga) range of vessels are constructed in accordance with the PED even though they are considered ‘pressure-less’. The result is a superior quality vessel design giving the end-user further confidence. The control (aka basic) vessel includes an oil load cell in which communicates with the Variomat Control Touch module, with the ability of multiple secondary vessels to be installed in series allowing pressure maintenance of larger systems whilst adapting to site restrictions.

As the Variomat control module modulates, water that spills into the vessel(s) on system expansion reduces from system pressure to atmospheric pressure resulting in an extraordinarily long service life of the vessel bladders and reduced service activities as there are no pre-charge checks apart from any small capacity balancing vessels. In addition to this, natural atmospheric degassing is carried out of the spilled water as a by-product which will further improve the quality of systems operating >70°C.

Taking a closer look at resilience, configuration of equipment is critical to eliminate or at least minimise any downtime. Although unlikely these could be caused from several factors, including power supply issues or product failure. To address this, we can look at several initiatives including:

• Master/slave equipment can be configured on different phases. Power supply issues are extremely rare within data centres, and if they do occur, they will generally be localised, and confined to one phase of the three-phase supply. If the master unit is fed by L1, and the slave by L2, in the event of the loss of a single phase, at least one of the units will remain in service. Once power is restored, any expansion vessel imbalance between master and slave modules adjusts the expansion levels automatically back to equilibrium. 
• If a unit needs to be taken out of commission, the Reflex Control Touch module will recognise this and, assuming the system is designed with master/slave, will automatically assign responsibility to the unit(s) still in service resulting in consistent operation until normal service is resumed.

Over recent years, there has been an appetite to improve the efficiency of systems and vacuum degassing is being preferred on critical systems. The Reflex Servitec range of vacuum degassers developed over the past 30 years are now being used extensively to improve the system efficiency by up to 10.6% and, although standard units are designed for systems up to 220mᶟ, bespoke units are regularly produced to accommodate larger systems such as PCW systems in data centres.

Although the principal purpose of the Reflex Servitec vacuum degasser is to improve system efficiency by removing all air in the pumped media, additional benefits can be realised including smoother laminar flow, and reduction of vibration as the hydraulic and thermal transfer properties of the system are optimised. The result of this enables system balancing to be undertaken with a smoother system.

Applying the same principle to the Servitec range design as that of the Variomat mentioned earlier, Reflex Control Touch or Basic control modules are used which helps with the consistency of components and understanding for on-site engineers. Premium pumps and self-cleaning motorised ball valves are also used in the design guaranteeing the resilience of the unit in service and when required, can work alongside master/slave pressure maintenance solutions.

When considering the correct selection of system pressure maintenance and degassing for critical systems, it is essential that this is done with not only the current requirements, but with ‘day ultimate’ in mind. Due to the dynamic nature of the Reflex design, almost all requirements can be accommodated for working with specialists in the field within Reflex.

The final selection can vary from a simple ‘off the shelf’ unit through to a bespoke packaged skid arrangement hydraulically and electrically complete. Combining the Reflex Selection Program (RSP) and applying the in-house specialist knowledge in data centre applications, the optimum solution can be found which almost always exceeds the customers’ expectations.