DIN EN 13941:2010-12

DIN EN 13941 specifies rules for design, calculation and installation for preinsulated bonded pipe systems for buried hot water distribution and transmission networks with pipe assemblies in accordance with EN 253, which are intended for continuous operation with hot water at various temperatures up to 120 °C and occasionally with peak temperatures up to 140 °C and maximum internal pressure 25 bar (overpressure). It assumes use of treated water, which by softening, demineralisation, deaeration, adding of chemicals, or otherwise has been treated to prevent internal corrosion and deposits in the pipes. DIN EN 13941 is not applicable for such units as: a) pumps, b) exchangers, c) boiler installations, tank installations, d) consumer installations. However, the full functional ability and durability of such units must be ensured in consideration of the impacts from the district heating system and other impacts occurring from the conditions under which they have been installed. The estimation of expected life with continuous operation at various temperatures is outlined in Annex B of EN 253:2009. DIN EN 13941 takes account of experience acquired, of new knowledge available, of the behaviour of material and of distribution of stresses and allowable deformations and also evolution in installation techniques. When use is made of the standard, the different sections of which it is made up must be interpreted as being interdependent and, because of this, cannot be dissociated. This standard consists of a main part and four annexes. Depending on the character of the individual clauses, distinction is made in this standard between Principles and Application Rules. The principles comprise: general statements, definitions and requirements, for which there is no alternative, as well as requirements and analytical models for which no alternative is permitted unless specifically stated. The principles are printed in normal typeface (10 point font). The application rules are generally recognised rules, which follow the principles and satisfy their requirements. It is permissible to use alternative design rules from the application rules given in this standard, provided that it is shown that the alternative rule accords with the relevant principles and it is at least equivalent with regard to the resistance, serviceability and durability characteristics achieved by the system. Annex A is part of the standard (principles). Annexes B, C and D have status as application rules. This standard contains a number of requirements aimed at ensuring the sound execution of distribution networks for district heating. To the extent possible, the requirements specified in DIN EN 13941 are functional requirements. The requirements and regulations contained in this standard should be assessed and applied in compliance with the intentions of the standard and in due consideration of the development taking place in the field it concerns. It is therefore assumed that the user of the standard has the requisite technical insight and adequate knowledge of legal and other external regulations that are of consequence to the practical application of the standard.