Lagnaval.is ONLINE SELECTION OF PIPE MATERIAL BASED ON WATER PROPERTIES

1. Lagnaval.isONLINE SELECTION OF PIPE MATERIAL BASED ON WATER PROPERTIES

2. As we all know the chemical properties of water may affect the performance of pipe material used to carry it. The temperature of the water is also an important factor for the performance of pipe material. Due to the properties of the soft, cold potable water and geothermal hot water used in Iceland, special demands are placed on material quality for pipes used in plumbing systems and this influences the material selection. It is therefore of uttermost importance that the latest information on pipe material technology is readily available to those who select pipe material, including designers, constructors and plumbers, as well as house owners. The website, lagnaval.is, was developed to meet this need and its purpose is to advise on suitable materials for buildings at different locations, type of applications and temperature (Árnason, 2004). Lagnaval.is has access to a database with information on pipeline materials and local water. The program can either be related to a particular district in Iceland or to a known chemical composition and temperature of water. The first edition of the website lagnaval.is was formally opened in 2002 included properties of water used in 240 district heating companies and 11 waterworks. At present the web-site includes in-house pipe systems at temperatures from 0°C to 80°C. The program is currently being reconstructed and expanded. A new computer code is used and the program is expanded to cover a much wider selection of cold water types, the properties of almost all hot water suppliers, and the major fresh water suppliers in Iceland. As we all know the chemical properties of water may affect the performance of pipe material used to carry it. The temperature of the water is also an important factor for the performance of pipe material. Due to the properties of the soft, cold potable water and geothermal hot water used in Iceland, special demands are placed on material quality for pipes used in plumbing systems and this influences the material selection. It is therefore of uttermost importance that the latest information on pipe material technology is readily available to those who select pipe material, including designers, constructors and plumbers, as well as house owners. The website, lagnaval.is, was developed to meet this need and its purpose is to advise on suitable materials for buildings at different locations, type of applications and temperature (Árnason, 2004). Lagnaval.is has access to a database with information on pipeline materials and local water. The program can either be related to a particular district in Iceland or to a known chemical composition and temperature of water. The first edition of the website lagnaval.is was formally opened in 2002 included properties of water used in 240 district heating companies and 11 waterworks. At present the web-site includes in-house pipe systems at temperatures from 0°C to 80°C. The program is currently being reconstructed and expanded. A new computer code is used and the program is expanded to cover a much wider selection of cold water types, the properties of almost all hot water suppliers, and the major fresh water suppliers in Iceland.

5. The goal of the program is to make available to constructors, plumbers and house owners a comprehensive information on appropriate materials for a particular type of pipe system for a particular district, and also to give building authorities in each district access to good technical information to use as base for their requirements. The goal of the program is to make available to constructors, plumbers and house owners a comprehensive information on appropriate materials for a particular type of pipe system for a particular district, and also to give building authorities in each district access to good technical information to use as base for their requirements.

6. Further goals are to enable the district heating companies and waterworks to foresee what effect a change in water chemistry or temperature will have on the choice of material in the future and on the pipes in the system at present. Further goals are to enable the district heating companies and waterworks to foresee what effect a change in water chemistry or temperature will have on the choice of material in the future and on the pipes in the system at present.

7. State of the art knowledge in the field can easily be evaluated from the program and it can be shown what influence new information from a research project could have on use of materials. The program should also facilitate quick distribution of research results concerning material quality or water chemistry as well as new information to the users.State of the art knowledge in the field can easily be evaluated from the program and it can be shown what influence new information from a research project could have on use of materials. The program should also facilitate quick distribution of research results concerning material quality or water chemistry as well as new information to the users.

8. The properties of potable water in Iceland, cold and warm, differ significantly from water in neighboring countries due to the geologic and meteorological conditions beeing considerably different. The potable water is almost exclusively groundwater. The dominant reservoir rocks are basaltic lavas and hyaloclastites greatly affecting the chemistry of the waters. The properties of potable water in Iceland, cold and warm, differ significantly from water in neighboring countries due to the geologic and meteorological conditions beeing considerably different. The potable water is almost exclusively groundwater. The dominant reservoir rocks are basaltic lavas and hyaloclastites greatly affecting the chemistry of the waters.

9. The salinity of the water depends mainly on the distance from the sea shore. The groundwater is of meteoric origin, but in just a few places, either originated from sea-water or has been affected by sea-water inflow. The salinity of the water depends mainly on the distance from the sea shore. The groundwater is of meteoric origin, but in just a few places, either originated from sea-water or has been affected by sea-water inflow.

10. The waters are generally of sodium bicarbonate type with pH 7-9.5 depending on the depth of circulation and rock formations. The influence of reactions with soil is much less and localized than is common elsewhere as vast areas of the country are barren. Groundwater in the active zones of volcanism and rifting has a high pH, =9 and very low mineralization as the basement rocks are highly permeable, unaltered and glassy. Even though pH is highest in groundwater in border areas on the active zones of rifting and volcanism, it may be low in areas within the active zones themselves due to geothermal influence. In the Tertiary basement in the western, northern and eastern part of the country, the groundwater has somewhat lower pH, 8.2-8.7, and higher mineral content due to lower permeability and more altered reservoir rocks. The surface and shallow waters have pH of about 6.5-7.5 and their mineralization varies mainly due to the distance from sea. The waters are generally of sodium bicarbonate type with pH 7-9.5 depending on the depth of circulation and rock formations. The influence of reactions with soil is much less and localized than is common elsewhere as vast areas of the country are barren. Groundwater in the active zones of volcanism and rifting has a high pH, =9 and very low mineralization as the basement rocks are highly permeable, unaltered and glassy. Even though pH is highest in groundwater in border areas on the active zones of rifting and volcanism, it may be low in areas within the active zones themselves due to geothermal influence. In the Tertiary basement in the western, northern and eastern part of the country, the groundwater has somewhat lower pH, 8.2-8.7, and higher mineral content due to lower permeability and more altered reservoir rocks. The surface and shallow waters have pH of about 6.5-7.5 and their mineralization varies mainly due to the distance from sea.

11. Low-temperature geothermal waters The low-temperature geothermal waters are in most cases of meteoric origin and slightly mineralized, typically with TDS 200-400 mg/l (Table). The mineralization increases by increased reservoir temperature of the geothermal fields. The concentration of silica is directly proportional to the formation temperature, but there is a great variation in sulfide, oxygen, carbonate, salt and even fluoride content. There exist a few sea-water contaminated geothermal fields mostly with salinity less than 10% of sea-water (3.5‰), but on the Reykjanes peninsula in Southwest Iceland and in Öxarfjördur in Northeast Iceland there are waters with much higher salinity, even up to that of sea-water. The pH of the saline geothermal fluids is in the range of 7.5-8.9. Waters with extremely high pH, 10-11, are also encountered, especially on the borders of the active volcanic zones. Waters with such extreme pH values are only used in a few small heating systems. Low-temperature geothermal waters The low-temperature geothermal waters are in most cases of meteoric origin and slightly mineralized, typically with TDS 200-400 mg/l (Table). The mineralization increases by increased reservoir temperature of the geothermal fields. The concentration of silica is directly proportional to the formation temperature, but there is a great variation in sulfide, oxygen, carbonate, salt and even fluoride content. There exist a few sea-water contaminated geothermal fields mostly with salinity less than 10% of sea-water (3.5‰), but on the Reykjanes peninsula in Southwest Iceland and in Öxarfjördur in Northeast Iceland there are waters with much higher salinity, even up to that of sea-water. The pH of the saline geothermal fluids is in the range of 7.5-8.9. Waters with extremely high pH, 10-11, are also encountered, especially on the borders of the active volcanic zones. Waters with such extreme pH values are only used in a few small heating systems.

12. As compared to geothermal waters in other countries the waters in Iceland have generally much lower concentration of dissolved solids. The pH of the waters is about 9.3-10.9, depending on reservoir rocks, temperature and salinity. In heating systems based on high-temperature geothermal fluids cold fresh water is heated by heat-exchange with geothermal water and steam. The heated fresh water differs from the geothermal waters mainly by lower mineralization, but certain species like magnesium are in much higher concentrations which may inflict precipitation of magnesium silicates. To prevent oxygen corrosion, condensed steam is commonly added to the heated waters-therefore they contain hydrogen sulfide. With increased reservoir temperature and subsequent increase of silica concentration, silicate minerals may precipitate by coolingAs compared to geothermal waters in other countries the waters in Iceland have generally much lower concentration of dissolved solids. The pH of the waters is about 9.3-10.9, depending on reservoir rocks, temperature and salinity. In heating systems based on high-temperature geothermal fluids cold fresh water is heated by heat-exchange with geothermal water and steam. The heated fresh water differs from the geothermal waters mainly by lower mineralization, but certain species like magnesium are in much higher concentrations which may inflict precipitation of magnesium silicates. To prevent oxygen corrosion, condensed steam is commonly added to the heated waters-therefore they contain hydrogen sulfide. With increased reservoir temperature and subsequent increase of silica concentration, silicate minerals may precipitate by cooling

13. Due to the fact that most Icelandic heating systems are through-flow systems with a single use of the water there may be a considerable buildup of scales even though just a few milligrams are precipitated from each liter Due to the fact that most Icelandic heating systems are through-flow systems with a single use of the water there may be a considerable buildup of scales even though just a few milligrams are precipitated from each liter

14. Fresh water distribution systems in Iceland are quite similar to such systems all over the world. Hot water and heating systems in Iceland are however quite unique in design as they are mostly through-flow systems and not based on recirculation of the same fluids. Fresh water distribution systems in Iceland are quite similar to such systems all over the world. Hot water and heating systems in Iceland are however quite unique in design as they are mostly through-flow systems and not based on recirculation of the same fluids.

15. The Icelandic heating systems are rather unique in design as they are mostly through-flow systems and not based on recirculation of the same fluids. In the Icelandic systems the geothermal water is piped to the user and mostly utilized directly both for house heating and as tap water without making use of heat-exchangers. The water is then disposed of into the sewer. In sulfide waters iron sulfides form inside steel pipes by corrosion and leaching of iron from the pipe wall and its subsequent reaction with sulfide in the water. The iron sulfide precipitates form a thin surface coating inside the pipes, which in most cases acts as a protective film effectively stopping further corrosion of the pipes and subsequent scaling. The Icelandic heating systems are rather unique in design as they are mostly through-flow systems and not based on recirculation of the same fluids. In the Icelandic systems the geothermal water is piped to the user and mostly utilized directly both for house heating and as tap water without making use of heat-exchangers. The water is then disposed of into the sewer. In sulfide waters iron sulfides form inside steel pipes by corrosion and leaching of iron from the pipe wall and its subsequent reaction with sulfide in the water. The iron sulfide precipitates form a thin surface coating inside the pipes, which in most cases acts as a protective film effectively stopping further corrosion of the pipes and subsequent scaling.

16. Plastic distribution pipes are widely used in these district heating systems and therefore the water may contain some oxygen.Plastic distribution pipes are widely used in these district heating systems and therefore the water may contain some oxygen.

17. The first edition of the website lagnaval.is was formally opened in 2002 included properties of water used in 240 district heating companies and 11 waterworks. At present the web-site includes in-house pipe systems at temperatures from 0°C to 80°C. The first edition of the website lagnaval.is was formally opened in 2002 included properties of water used in 240 district heating companies and 11 waterworks. At present the web-site includes in-house pipe systems at temperatures from 0°C to 80°C.

18. CRITERIA FOR PIPE SELECTION The recommendations built into the program lagnaval.is are based on both theory and long experience of material performance in different environments. The criteria for recommendations of the selection of pipes which are built into the program are based on both theory, information from the pipe producers and long experience of material performance in different environments. CRITERIA FOR PIPE SELECTION The recommendations built into the program lagnaval.is are based on both theory and long experience of material performance in different environments. The criteria for recommendations of the selection of pipes which are built into the program are based on both theory, information from the pipe producers and long experience of material performance in different environments.

19. CRITERIA FOR PIPE SELECTION There are, for house systems considered, the following possible pipe materials: copper, normal black steel, galvanized steel, AISI 304 stainless steel, AISI 316 stainless steel, PP, PB, aluminium/plastic, HD-PE, MD-PE (PE-RT) and PEX. For the plastic pipes and aluminum/plastic temperature is the main criteria for application; temperature is also a criteria for some of the metals but most of the restrictions on use of metal pipes are based on chemical composition of the water. European standards on plastic piping require 50 years lifetime of the system. Recommendation is aimed to fulfill these requirements and to gain similar lifetime for the metal piping systems. CRITERIA FOR PIPE SELECTION There are, for house systems considered, the following possible pipe materials: copper, normal black steel, galvanized steel, AISI 304 stainless steel, AISI 316 stainless steel, PP, PB, aluminium/plastic, HD-PE, MD-PE (PE-RT) and PEX. For the plastic pipes and aluminum/plastic temperature is the main criteria for application; temperature is also a criteria for some of the metals but most of the restrictions on use of metal pipes are based on chemical composition of the water. European standards on plastic piping require 50 years lifetime of the system. Recommendation is aimed to fulfill these requirements and to gain similar lifetime for the metal piping systems.

20. The chemical composition of water in different district heating systems is kept in the data­base along with tables relating recommendation, to upper and lower levels of each chemical of relevance, and other relevant variables like temperature, for a particular piping material.   The recommendation for each distribution system is calculated online based on the temperature and the composition of the water.  Where there are many measurements available for a particular distribution system, the worst case is used for recommendation. The chemical composition of water in different district heating systems is kept in the data­base along with tables relating recommendation, to upper and lower levels of each chemical of relevance, and other relevant variables like temperature, for a particular piping material.   The recommendation for each distribution system is calculated online based on the temperature and the composition of the water.  Where there are many measurements available for a particular distribution system, the worst case is used for recommendation.

21. If one of the last three systems is chosen, consultancy in lagnaval.is is independent of location of the house. If one of the first four systems is chosen, the next step is to locate the house and information in the database on cold and hot water supplied to the house is used to recommend suitable pipe materials (and radiators in case of open district heating). If a visitor on the web site wants recommendations for a new water supply not included in the database, he can put in his own chemical specification and obtain appropriate pipe material recommendation. In the recommendations, materials are divided in three categories Green material. Recommended material. Yellow material. Recommended if some requirements are fulfilled. Red material. Not recommended. If one of the last three systems is chosen, consultancy in lagnaval.is is independent of location of the house. If one of the first four systems is chosen, the next step is to locate the house and information in the database on cold and hot water supplied to the house is used to recommend suitable pipe materials (and radiators in case of open district heating). If a visitor on the web site wants recommendations for a new water supply not included in the database, he can put in his own chemical specification and obtain appropriate pipe material recommendation. In the recommendations, materials are divided in three categories Green material. Recommended material. Yellow material. Recommended if some requirements are fulfilled. Red material. Not recommended.