ERT™ Power Section Specification
500ERTcr6780
5" 6:7 Lobes 8.0 Stages
Rotor Specifications
Overall Length 239.00 in
Avg. Diameter 2.635 in
Contour Length 233.00 in
Eccentricity 0.192 in
Major Diameter 3.018 in
Head Diameter 2.900 in
Head Length 6.00 in
Weight 365 lb
Thread Form 2 3/8" HEF
Stator Specifications
Overall Length 246.00 in
Tube OD 5.00 in
Contour Length 227.50 in
Tube ID 3.235 in
Rubber Cut-back
Side 1: 7.50 in
Side 2: 11.00 in
Weight 546 lb
Material Alloy Steel
Performance Specifications
Flow Range 150-350 GPM
Rev per Unit Volume 0.78 Rev/Gal
Speed Range 117-274 RPM
No Load Pressure Loss 198 psi
  POB XTH
Max Rec Press 2,140 psi 2,290 psi
Torque @ Max Press 6,600 ft-lbs 7,070 ft-lbs
Stall Pressure 3,910 psi 4,190 psi
Stall Torque 13,460 ft-lbs 14,430 ft-lbs
Stator Minors and Fit (in) at 70°F
  XTH POB
Group Minor Fit Minor Fit
T 2.637 -0.002
0 2.646 -0.011 2.646 -0.011
5 2.660 -0.025 2.660 -0.025
7 2.670 -0.035
 
Reline Lengths (in) Max 246 Min 240
Alt. Stator OD (in)   -   -
Alt. Rotor Diameter (in) 2.637 - - -

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 2,000 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 3,500 Torque (ft-lb) 0 5,000 10,000
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 0.05
Speed
150 GPM 250 GPM 350 GPM Differential Pressure (psi) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 Speed (RPM) 0 100 200 300
Mechanical Power
150 GPM 250 GPM 350 GPM Differential Pressure (psi) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 Mechanical Power (hp) 0 100 200 300 400 500
©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.