V-Flex Valve System Welcomed by DHS Designers

Leading insulated pipe solutions specialist, Flexenergy, who are based in Glenrothes, has been working alongside consulting engineers, energy managers and contractors for over 30 years, helping to optimise the efficiency of pre-insulated pipe networks serving district heating schemes and hot and chilled water distribution systems. The company’s position as the sole distributor in the UK and Ireland of Flexalen pre-insulated pipe technology, manufactured by Thermaflex in the Netherlands, makes Flexenergy a valued partner for designers and specifiers focused on system performance, environmental impact and return on investment.

One of its more popular products is the Flexalen 600 system, which is made up of three basic components, all of which give it unique advantages over other plastic insulated pipe systems:

1) High impact HDPE outer casing

2) Unique Class PE foam insulation

3) PB-1 carrier pipes

The high quality system is extremely lightweight, highly flexible, easy to install and includes a full range of easy to use fittings. It is a fully welded, all plastic system so no corrosion occurs guaranteeing a fit and forget, maintenance free solution. All products are designed to be environmentally friendly and energy-saving.

In recent years, interest has grown considerably in district heating applications using pre-insulated polybutene (PB) ‘plastic’ pipe, and specifiers and designers are now keen to use any new product enhancements to the control mechanisms that can add value beyond thermal efficiency and system life cycle cost.

As a result, Flexenergy has developed the V-Flex valve range, a system to add more effective control to the ‘plastic’ proposition and can be used for community heating schemes, biomass CHP, geothermal and heat recovery networks.

The V-Flex valve system is the first such pre-insulated valve system to be available in the UK for plastic pipe systems and has been welcomed by DHS (District Heating System) designers for providing much greater control over heat networks. In effect, it means that the valves can be used to shut down entire networks or to isolate individual streets/ properties making network maintenance and extensions much easier.

V-Flex transforms the ability of operators to control and service PB networks by delivering zonal control via pre-insulated valve technology that can be fusion welded directly to the main network.

Some of the key features of the new valve system include:

  • Polyethylene casing
  • PUR Foam insulation
  • Key operated steel ball valve
  • Polybutene pipe tails for fully welded connection
  • Temperature range up to 95°C

The valves can be specified for single or twin pipe applications and as they are fusion welded, they can be buried in the ground without the need for large and costly inspection chambers enabling both clients and installers cost and speed efficiencies. Having said that, Flexenergy do supply chambers that come in a number of sizes (to accommodate depth variation) in order to provide flexibility in network or zonal control. Each chamber provides easy access to the valve and includes a lockable lid as an option.

As Sandy Fairley, Sales Director at Flexenergy explains: “The V-Flex valve system is a big step in the right direction for us and introduces new levels of control over heat networks. The new system also means that it is now possible to create an all-plastic fusion welded system, including valves, reducing any additional onsite mechanical joints.”

The design attributes of polybutene and the Flexenergy product range helps to reduce heat loss on networks, which do not suffer from the same corrosive limitations as steel. They, therefore, provide numerous benefits for scheme owners, such as improved overall energy efficiency, lower long term system life cycle costs and extended operational periods between pipe replacements.

The first project using the V-Flex valve system was undertaken for Barratt London, who selected the Flexalen pre-insulated pipe work as the most appropriate product for a new District Heating Network installed to service 164 new homes being built in Camden Road, London.

Since that time, a further project using the V-Flex valve system has been undertaken at Nottingham University’s Brackenhurst Campus. Requiring a mains repair and also a route change to accommodate a new building, Flexenergy was asked to help in the isolation of sections as the project progressed and to help in isolating the new network for future connections. The V-Flex valve suited perfectly and three sets of valves were installed at different points on the system. Flexenergy also provided bespoke prefabricated flange valves allowing their approved installer, Young Contracting, to connect to a range of other materials reducing the amount of time spent on site.

Flexenergy is currently setting up a national network of approved installers to give designers even more confidence in the installation of the system. Young Contracting, having installed Flexalen pipes for many years previous to this was an immediate choice for this project.