P11
The only physical thing you can see in the pre-insulated, buried system are the pre-insulated valves in chambers. The energy company should establish a routine for planned chamber inspections 1-2 times a year, where the valves are operated. This ensures a long service life of the pre-insulated valves. In addition, it is possible to install detectors in chambers, which sends a message if the chamber is flooded.
OLD PRE-INSULATED PIPE SYSTEMS WITHOUT SURVEILLANCE SYSTEM AND PIPE SYSTEM IN CONCRETE DUCTS
In these systems, the only way to monitor the condition is to make thermographic surveillance as periodic inspections of the DH networks. If there are leaks in the steel pipes with major water loss, then it is also possible to locate the area where the leak is by analyzing data from meters in the system and at consumers’. In these systems, damages are not found until they are comprehensive e.g. moisture coming from the outside and spreading in the system or an actual rupture of the steel pipes with water loss as a result. In old systems with surveillance wires, it will therefore be much preferable to update the system to an active surveillance system, so you can always react quickly, before the faults evolve to large and expensive damages. DIGITALIZATION AND FUTURE DEVELOPMENT The trend is towards the energy companies wanting more and more data from the systems. Data, from which they can make the right choices. This is also true of pre-insulated pipe systems, and we will certainly see a trend towards more ”digitized” pre- insulated pipe systems.
EXISTING SYSTEMS In many pre-insulated pipe systems with a surveillance system that has been in operation in a few or many years, the surveillance system is often not up-to-date regarding drawing material and it is often a passive system. It is recommended to update the drawing material and make precise, as-built drawings, and then upgrade the surveillance systems to active, continuously monitored surveillance systems. This is possible for skilled measuring technicians and will certainly extend the service life of the pre-insulated pipe system instead of continuing with the “old” one, because then it is possible to repair old faults and respond quickly to new ones. In old pre-insulated pipe systems, there is often a problem with leaky casing joints, which can be located with an updated surveillance system. It is recommended to make a renovation plan for exchanging old leaky casing joints, because it will prevent further corrosion of steel pipes and leakages in the pipe system. There are products and techniques available to replace old straight joints, bend joints and T-joints without interrupting the operation and cutting the steel pipes. It requires a special installation technique and trained fitters.
For further information please contact: Peter Jorsal, pjo@logstor.com
www.dbdh.dk
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