Butt fusion heating and cooling times DVS 2207-11
202008A – AQTTB
Date Issued: 12-Aug-2020
The standard referenced for butt fusion of polypropylene pipe, DVS 2207-11, was updated in 2017 to provide for reduced heating and cooling times. During the revision process, these changes were not evaluated for multi-layer, faser-composite (MF) pipes. Aquatherm has now completed the testing and evaluation of these changes and has adopted them for use across all sizes/SDRs of Aquatherm MF piping.
The following is a brief description of the butt fusion parameters and identification of any changes between the previous version (2008) and current standard (2017). Any changes are noted in red.
Table 1 – Changes other than heat/cool times
|Item||Description of change|
|Permissible gap between pipe ends after facing/planing||No change|
|Permissible misalignment of pipe ends (max 10% of wall thickness)||No change|
|Heater temperature, 210±10°C (410±18°F)||No change|
|Equalizing pressure (previously alignment pressure in 2008) – Bead-up/adjustment in Installer Manual||No change to actual interfacial pressure (14.5 psi), just name change|
|Preheating pressure (previously heating-up pressure in 2008) – Heating pressure in Installer Manual||No change to actual interfacial pressure (14.5 psi), just name change|
|Joining pressure – Machine pressure in Installer Manual||No change|
|Bead height||No change for existing sizes/wall thicknesses, added requirement for wall thickness above 1.97 in. (50-70mm)|
Table 2 – Reduction in Heating Times from 2008 Edition
|Wall, mm||Heat time, sec.
Table 3 – Reduction in Fusion/Cooling Times from 2008 Edition
|Wall, mm||DVS 2207-11||Reduction at 60-80°F|
|Ambient temperature at time of fusion|
|Standard||≤60°F (≤15°C)||60-80°F (15-25°C)||>80°F (>25°C)|
Reducing cooling time under pressure, removal of equipment
Butt fusion needs to cool under pressure to ensure proper connections. Cooling times under pressure for butt fusion connections can be reduced if the joint is supported properly and not subjected to any loads for the remainder of the cooling time.
For example, at 70°F the cooling time for 6 in., SDR 11 pipe can be reduced from 14 minutes to 9 minutes if the joint is not subjected to any stress for the remaining 5 minutes.
Table 4 – Reduced cooling times under pressure with no load on joint and proper support
|Wall, mm||Cooling time, minutes|
|DVS 2207-11 (2017)|
*No load on joint, properly supported for the full duration of the standard cooling time