ERT™ Power Section Specification
675ERTcr7850
6.75" 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 677 lb
Thread Form 2 7/8" API Reg
Stator Specifications
Overall Length 194.50 in
Tube OD 6.75 in
Contour Length 180.00 in
Tube ID 4.477 in
Rubber Cut-back
Side 1: 7.25 in
Side 2: 7.25 in
Weight 860 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 1,380 psi 1,480 psi
Torque @ Max Press 13,770 ft-lbs 14,750 ft-lbs
Stall Pressure 2,530 psi 2,710 psi
Stall Torque 25,190 ft-lbs 26,990 ft-lbs
Stator Minors and Fit (in) at 70°F
  XTH POB
Group Minor Fit Minor Fit
E 3.999 0.015 3.999 0.015
0 4.008 0.006 4.008 0.006
2 4.017 -0.003 4.017 -0.003
4 4.023 -0.009 4.023 -0.009
 
Reline Lengths (in) Max 194 Min 188
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 1,000 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 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 2,000 Torque (ft-lb) 0 5,000 10,000 15,000 20,000
Fit Increase
Change in Temperature (°F) 0 50 100 150 200 250 300 Fit Increase (in) 0 0.01 0.02 0.03
Speed
300 GPM 500 GPM 700 GPM Differential Pressure (psi) 0 500 1,000 1,500 2,000 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 Mechanical Power (hp) 0 200 400 600
©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.