# Pipe and Tube Welds

on . Posted in Welding Engineering

## Axial Force on CJP ButtWeld formula

 $$\large{ \sigma = \frac{ P }{ A } }$$ $$\large{ \sigma = \frac{ 4 \; P }{ \pi \; \left( D^2 \;-\; d^2 \right) } }$$ $$\large{ d = D \;-\; 2 \; t }$$

### Where:

$$\large{ \sigma }$$ (Greek symbol sigma) = stress in weld

$$\large{ \pi }$$ = Pi

$$\large{ d }$$ = pipe/tube inside diameter

$$\large{ D }$$ = pipe/tube outside diameter

$$\large{ P }$$ = total axial force

$$\large{ A }$$ = weld throat area

$$\large{ t }$$ = weld throat thickness

## Shear Force on CJP ButtWeld formula

 $$\large{ \tau = \tau_p = \frac{ V }{ A } }$$ $$\large{ \tau = \tau_p = \frac{ 4 \; V }{ \pi \; \left( D^2 \;-\; d^2 \right) } }$$ $$\large{ d = D \;-\; 2 \; t }$$

### Where:

$$\large{ \tau }$$ (Greak symbol tau) = shear stress

$$\large{ \tau_p }$$ (Greak symbol tau) = shear stress parallel to weld direction

$$\large{ \pi }$$ = Pi

$$\large{ d }$$ = pipe/tube inside diameter

$$\large{ D }$$ = pipe/tube outside diameter

$$\large{ V }$$ = total shear force

$$\large{ A }$$ = weld throat area

$$\large{ t }$$ = weld throat thickness

## Bending Moment on CJP ButtWeld formula

 $$\large{ \sigma = \frac{ M }{ E } }$$ $$\large{ \sigma = \frac{ 32 \; M }{ \pi \; D^3 \; \left[ 1 \;-\; \left( \frac{ d }{ D } \right)^4 \right] } }$$ $$\large{ d = D \;-\; 2 \; t }$$

### Where:

$$\large{ \sigma }$$ (Greek symbol sigma) = stress in weld

$$\large{ \pi }$$ = Pi

$$\large{ d }$$ = pipe/tube inside diameter

$$\large{ D }$$ = pipe/tube outside diameter

$$\large{ M }$$ = bending moment

$$\large{ E }$$ = modulus of weld section

$$\large{ t }$$ = weld throat thickness

## Torsion Moment on CJP ButtWeld formula

 $$\large{ \tau_p = \frac{ T }{ E } }$$ $$\large{ \tau_p = \frac{ 16 \; T }{ \pi \; D^3 \; \left[ 1 \;-\; \left( \frac{ d }{ D } \right)^4 \right] } }$$ $$\large{ d = D \;-\; 2 \; t }$$

### Where:

$$\large{ \tau_p }$$ (Greak symbol tau) = shear stress parallel to weld direction

$$\large{ \pi }$$ = Pi

$$\large{ d }$$ = pipe/tube inside diameter

$$\large{ D }$$ = pipe/tube outside diameter

$$\large{ T }$$ = torque force

$$\large{ E }$$ = modulus of weld section

$$\large{ t }$$ = weld throat thickness