Piston Rod Root Stress

 
Piston rod root stress is used to design the appropriate piston rod attachment preload levels.  Ariel piston rod to crosshead nut preload levels are 30,000 psi.  This is well above 1-1/2 times the root stress potential from inertia and gas loading. Ariel does not publish a limit based upon piston rod root stress.  Root areas for Ariel frames are below:
 
 
 

Frame Model

Rod Diameter (in)

Crosshead Thread Pitch

Thread Root Area (in2)

JGM:N:P:Q

1-1/8 inch

1"-12

0.625 in2

JG / JGA

1-1/8 inch

1"-12

0.625 in2

JGW:R:J

1-1/2 inch

1-3/8"-12

1.260 in2

JGH:E:K:T

2 inch

1-3/4"-12

2.120 in2

JGC:D

2-1/2 inch

2-1/4"-8

3.420 in2

JGZ:U

2-7/8 inch

2-5/8"-8

4.76 in2

KBB:V

3-1/8 inch

2-7/8"-8

5.780 in2

 
 
 
 
 
 

Ariel Corporation Application Manual  
3 July 2009