Due to the existing vacuum in the double jacket of this riser pipe, fewer heat losses occur during the pumping-up of deep water. The riser pipe is currently available in a dimension DA 60.3 mm up to approx. 1,100 m installation depth.
The following construction was determined in order to allow a cost-efficient construction method:
The pipe lengths amount to 6 m. A Whitworth thread is to be chosen preferably as connection, while pressure density is achieved by two O-rings per each connection. The threaded socket of the connection has the same external diameter as the external pipe. Its advantage, is that this riser pipe can be easily used as an insert pipe, despite a very narrow internal diameter of the outer pipe. In order to generate a vacuum, no set-up valve is used but the sealing screw is flush-mounted with the outer diameter. The individual vacuum chambers are separated from each other by supporting washers which have culvert holes.
The riser pipe material can either be stainless steel or – in case of particularly problematic waters – the resistance can also be improved by a plastic coating. As a standard feature, an inspection document about the vacuuming is issued.