SN Calculation

The app returns the SN value of a pipe according two main methods: a) by the use of formula (1) b) by test method and formulas contained in EN ISO 9969

Nominal ring stiffness (Solid-wall pipes made of PE or PVC-U)
Nominal ring stiffness (Structured-wall pipes tested according to ISO 9969)

SOLID-WALL PIPES MADE OF PE OR PVC-U
Raw material
Young’s modulus	E	(MPa)
SDR	SDR	( )
Nominal ring stiffness	SN	(KPa)
Creep modulus	c	( )
Long term young modulus	E0	(MPa)
Long term stiffness	SN₀	(KPa)
STRUCTURED-WALL PIPES TESTED ACCORDING TO ISO 9969
Load @ 3% (ISO 9969)	F_3%	(N)
Sample length	L	(mm)
Pipe internal diameter	Di	(mm)
Nominal ring stiffness	SN	(KPa)