ERT™ Power Section Specification
650ERT7867
6.5" 7:8 Lobes 6.7 Stages
Rotor Specifications
Overall Length 251.25 in
Avg. Diameter 4.014 in
Contour Length 242.50 in
Eccentricity 0.252 in
Major Diameter 4.517 in
Head Diameter 4.000 in
Head Length 8.75 in
Weight 895 lb
Thread Form 3.000 XDV
Stator Specifications
Overall Length 260.00 in
Tube OD 6.50 in
Contour Length 240.50 in
Tube ID 5.540 in
Rubber Cut-back
Side 1: 9.75 in
Side 2: 9.75 in
Weight 961 lb
Material Alloy Steel
Performance Specifications
Flow Range 300-700 GPM
Rev per Unit Volume 0.27 Rev/Gal
Speed Range 81-189 RPM
No Load Pressure Loss 221 psi
  POB XTH
Max Rec Press 1,850 psi 1,980 psi
Torque @ Max Press 17,980 ft-lbs 19,270 ft-lbs
Stall Pressure 3,390 psi 3,630 psi
Stall Torque 32,910 ft-lbs 35,260 ft-lbs
Stator Minors and Fit (in) at 70°F
  XTH POB
Group Minor Fit Minor Fit
B 4.001 0.013
0 4.011 0.003 4.013 0.001
1 4.024 -0.010
 
Reline Lengths (in) Max 260 Min 254
Alt. Stator OD (in)   -   -
Alt. Rotor Diameter (in) - - - -

Max DP for reliable operation will vary based on
operational conditions. Refer to ERT Operational
Guidelines for guidance.

Torque
Differential Pressure (psi) 0 2,000 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 2,000 3,000 Speed (RPM) 0
Mechanical Power
Differential Pressure (psi) 0 2,000 Mechanical Power (hp) 0
Torque
Differential Pressure (psi) 0 500 1,000 1,500 2,000 2,500 3,000 Torque (ft-lb) 0 10,000 20,000 30,000
Fit Increase
Change in Temperature (°F) 0 50 100 150 200 250 300 Fit Increase (in) 0 0.01 0.02 0.03 0.04
Speed
300 GPM 500 GPM 700 GPM Differential Pressure (psi) 0 500 1,000 1,500 2,000 2,500 3,000 Speed (RPM) 0 50 100 150 200 250
Mechanical Power
300 GPM 500 GPM 700 GPM Differential Pressure (psi) 0 500 1,000 1,500 2,000 2,500 3,000 Mechanical Power (hp) 0 200 400 600 800
©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.