3.4. Domestic pipes

Transcription

1 3.4. Domestic pipes Pipe quality The following may be used as pipe grades for domestic pipes: a) Steel piping In accordance with the following specifications: - DIN 2448/1629 smooth, seamless steel pipes - DIN 2458/1626 smooth or resistance-welded steel pipes - DIN 2440 middleweight threaded pipes black, welded black, seamless galvanised, welded galvanised, seamless

2 - DIN 2441 heavy-duty threaded pipes black, welded black, seamless galvanised, seamless - industrial pipes semi-smooth, resistance-welded annealed, seamless smooth, seamless - plastic-coated steel pipes b) Copper pipes In accordance with the following specifications: - DS 2110 copper pipes The gas supplier s permission must be obtained when using gas from the first gas family. c) Pipes of a different quality in domestic piping may only be used when approved by the Danish Safety Technology Authority Pipe joints The following may be used as pipe joints for domestic pipes: (See also the provisions for piping in sections c) and d).) a) Steel piping Pipes in accordance with DIN 2440 and DIN 2441 can be joined via: - Soft-poured or forged threaded (not threaded lengthways, however), where the joint is made with flax twine and approved gas-resistant, non-toughened joint paste, joint tape or equivalent. - Joints with tapered conic surface (metal against metal ). - Threaded flanges, in which the flange joint consists of suitable, gas-resistant material. - Welded joints (never try to weld galvanised pipes, however), links, approved by the Danish Safety Technology Authority. Threaded joints may only be used up to a diameter of 50 mm. Industrial pipes and plastic-coated steel pipes may be joined via: - Links, approved by the Danish Safety Technology Authority. - Steel or metal capillary soldering s soldered with silver solder that is at least 45% silver (L- Ag 55 Sn and L-Ag 45 Sn and flux in accordance with DIN 8511)

3 Piping - Compression s and cut s following acceptance by the gas supplier. - Welding. b) Copper pipes - Capillary soldering s soldered with silver solder that is at least 45% silver. (L-Ag 55 Sn and L-Ag 45 Sn) and flux in accordance with DIN 8511 (F-SH1). - Ball valve s. - Compression s with metallic sealing and support bush. Copper pipes may only be used up to a diameter of 28 mm. c) Pipe joints of a different type in domestic piping may only be used when approved by the Danish Safety Technology Authority. a) The provisions in the Building Regulations - general requirements for installation, etc. apply at all times and must be complied with. b) Pipes must be placed in the shortest possible and most appropriate route. c) Pipes should be laid without superfluous joints. d) Visible pipes must be laid in straight lines; vertical pipes must be upright and transverse pipes must be horizontal. When placing detached pipes along walls or under ceilings, pipe brackets must be used. (Pipe bracket distance should not normally exceed 60 x the pipe s external diameter.) The pipe brackets should support the pipes and ensure that they are an appropriate distance from walls and ceilings. However, the pipes may be placed against walls or sides of buildings provided that galvanised pipes and s or plastic-coated copper pipes are used and the joint is secured with pipe brackets. e) Pipes may be laid as shown in figures 3-3 and 3-4: - 1. Visible piping Hidden piping Embedded piping

4 A-3: Piping systems Figure 3-3 Figure 3-4 Loftsrum = Attic Nedhængt loft = False ceiling Hævet gulv = Raised floor Krybekælder = Crawl space Kælder = Basement Redskabsrum = Tool shed

5 A-3: f) Embedded pipes must be laid in one length. Branches are not permitted. Piping systems Embedding may only be implemented with sand and cement, and the pipes must be rust-resistant with PE cases or PE covers. Pipes may not be embedded inside flue jambs. g) Concealed pipes should as far as possible be laid in one length. Necessary joints must be produced by welding for steel pipes and capillary soldering for copper pipes. When necessitated by specific conditions, galvanised steel pipes with threaded joints may be used after permission has been obtained from the gas supplier. h) Where pipes are being laid in buildings that are equipped with expansion joints, care should be taken that the expansion and contraction of the joint do not affect the pipe. i) Pipes are not permitted to be run through safe rooms or protective shelters, or through chimneys, ventilation channels, refuse ducts or similar. j) Pipes may not be used as weight-bearing building elements, and must be laid in such a way that they are not exposed to moisture. k) When laying pipes through floor partitions made of concrete or wood, bush pipes must be used. l) When installing pipes in self-contained fire compartments, such as stairways, the passage through the wall must be sealed to a level corresponding to the building element s fire resistance. Please see the provisions in the Building Regulations. Table 3-2 states requirements for joints involving various piping materials. Table 3-2 Piping Pipe type and joint method Hot-galvanized pipes and black pipes Copper pipes Soft steel pipes Threaded Welding Soldering Compression Compression Visible Yes Yes 1) Yes Yes Yes Hidden No Yes 1) Yes No No Embedded No No No No No 1) Hot-galvanized pipes may not be welded

6 Pipe protection a) Untreated steel pipes and s must be protected with a rust-resistant coating. Galvanised pipes and s and copper pipes and s do not need any special protection. b) Pipes in damp, inaccessible or unventilated rooms should be protected in one of the following ways: - Corrosion proofing for underground pipes in accordance with section By embedding in asphalt. - By using protective pipes, where the space is filled with insulation material or similar. c) For pipes that carry gas from the first gas family, and which may be exposed to temperatures low enough that there is a risk of condensation of the gas, the gas supplier may require the pipes to be insulated to the necessary extent.