Power Section Specification
650-7850
6.565" 7:8 Lobes 5.0 Stages
Rotor Specifications
Overall Length 188.00 in
Avg. Diameter 4.014 in
Contour Length 181.00 in
Eccentricity 0.252 in
Major Diameter 4.517 in
Head Diameter 4.000 in
Head Length 7.00 in
Weight 653 lb
Thread Form 2 3/8" API Reg
Stator Specifications
Overall Length 194.00 in
Tube OD 6.57 in
Contour Length 179.50 in
Tube ID 5.500 in
Rubber Cut-back
Side 1: 7.25 in
Side 2: 7.25 in
Weight 616 lb
Material Alloy Steel
Performance Specifications
Flow Range 300-600 GPM
Rev per Unit Volume 0.28 Rev/Gal
Speed Range 84-168 RPM
No Load Pressure Loss 142 psi
  POB XTH
Max Rec Press 1,180 psi 1,300 psi
Torque @ Max Press 11,150 ft-lbs 12,260 ft-lbs
Stall Pressure 1,780 psi 1,960 psi
Stall Torque 16,720 ft-lbs 18,400 ft-lbs
Stator Minors and Fit (in) at 70°F
  POB XTH
Group Minor Fit Minor Fit
T 3.990 0.024
0 4.001 0.013 4.001 0.013
2 4.024 -0.010
4 4.032 -0.018 4.032 -0.018
7 4.059 -0.045
Reline Lengths (in) Max 194 Min 188 Alternate Stator OD (in): 6.750 / 7.000
Torque
Differential Pressure (psi) 0 1,000 Torque (ft-lb) 0
Fit Increase
Change in Temperature (°F) 0 100 200 300 Fit Increase (in) 0
Speed
Differential Pressure (psi) 0 1,000 Speed (RPM) 0
Mechanical Power
Differential Pressure (psi) 0 1,000 2,000 Mechanical Power (hp) 0
Torque
Differential Pressure (psi) 0 500 1,000 1,500 Torque (ft-lb) 0 5,000 10,000 15,000
Fit Increase
Change in Temperature (°F) 0 50 100 150 200 250 300 350 Fit Increase (in) 0 0.02 0.04 0.06 0.08 0.1
Speed
300 GPM 450 GPM 600 GPM Differential Pressure (psi) 0 500 1,000 1,500 Speed (RPM) 0 50 100 150 200
Mechanical Power
300 GPM 450 GPM 600 GPM Differential Pressure (psi) 0 500 1,000 1,500 2,000 Mechanical Power (hp) 0 100 200 300 400
©2026 NOV. All rights reserved. Except as noted, all trademarks referenced in this document are trademarks of NOV. Performance curves describe theoretical performance with 175°F (79°C) water and are for reference only. Operational fit and drilling conditions will affect performance. Operation above maximum recommended limits will reduce life. Specification data are subject to change without notice.
PS App v.