BE-15 Pipes and Materials: Welding of Plastic Pipes

Welding force

Influence of the welding force

The welding load serves to bring the plastified join partners into contact in such a way that the molecular chains are sufficiently mixed and that the semi-crystalline structures, which determine the strength of the polyethylene, can develop.

The necessary welding load (specific jointing pressure) for polyethylene is determined by the DVS 2207-1 (German Welding Society) and has to be converted for the corresponding welding surfaces (load per surface).

Calculation of the welding force

A Pipe = ( d o − d i )⋅π 4 or ≈ d m ⋅π⋅s MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKfMBHbqedmvETj2BSbqee0evGueE0jxyaibaieYdNi=BH8uipC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeaacaGaaiaabeqaaeaabaWaaaGceaqabeaacaWGbbWaaSbaaSqaaiaadcfacaWGPbGaamiCaiaadwgaaeqaaOGaeyypa0ZaaSaaaeaacaGGOaGaamizamaaBaaaleaacaWGVbaabeaakiabgkHiTiaadsgadaWgaaWcbaGaamyAaaqabaGccaGGPaGaeyyXICTaeqiWdahabaGaaGinaaaaaeaacaWGVbGaamOCaaqaaiabgIKi7kaadsgadaWgaaWcbaGaamyBaaqabaGccqGHflY1cqaHapaCcqGHflY1caWGZbaaaaa@4BFF@

Formula: 

Calculation of the welding surface

APipe = welding surface
do = outer diameter of the pipe
di = inner diameter of the pipe
dm = average diameter of the pipe
s = wall thickness

F= p spec ⋅ A Pipe MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKfMBHbqedmvETj2BSbqee0evGueE0jxyaibaieYdNi=BH8uipC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeaacaGaaiaabeqaaeaabaWaaaGcbaGaamOraiabg2da9iaadchadaWgaaWcbaGaam4CaiaadchacaWGLbGaam4yaaqabaGccqGHflY1caWGbbWaaSbaaSqaaiaadcfacaWGPbGaamiCaiaadwgaaeqaaaaa@3BBB@

Formula: 

Calculation of the necessary welding force

F = welding force
pspec = specific jointing pressure
APipe = welding surface

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