Proposed Pipe Size To Be Used :
SURELINE High Density Polyethylene Pipe (HDPE):
Other Properties :


Wall Thickness 
0.3125 inches 
Outside Diameter (O.D.) SURELINE 
7.8280 inches 
Inside Diameter (I.D.) SURELINE 
7.2030 inches 


Existing Steel Pipe : 

Original Wall Thickness 
0.331 inches 
Weight of Pipe 
26.68 lbs/lf 
Strength 
145.00 psi 
Outside Diameter (O.D.) 
8.740 inches 
Inside Diameter ( I.D.) 
8.079 inches 


Modulus of elasticity: 



tension 
15,000,000 psi 

Compression 
6,000,000 psi 
Calculation of Design Pressure: 

The maximum pressure determined by 49 CFR 192.123 for a single plastic pipe is: 
100 psi 
The lowest operating temperature for plastic pipe as per code is: 
29 ° C, 20 ° F 
Maximum operating temperature at 100 psi pressure class for Thermoplastic (DOT limits) ; wall thickness minimum 1.57mm (0.062 inches) is:

60 ° C, 140 ° F 


The design pressure for gas lines is determined According to AGA formula as follows:

P= 2*S*F/(R1) – 2*S*t*F/ (Dt) 

T= PD/(P+2*S*F) 

Design Pressure 
P = ? psi 
Outside Diameter 
D= 7.828 inches 
The Long Term Hydrostatic Strength 
S= 1.600 psi 
The Wall Thickness 
t= 0.313 inches 


The design factor used to compensate for stresses other than internal pressure, such as bending in installation, earth loading, subsidence, temperature changes and fitting compressions, all applicable to freely buried plastic pipe, is allocated to be 0.32 by GA CFR 192.121.
In absence of the factor determined for SURELINE pipe, which is restrained pipe, the design factor will be:
F= 0.50