ERT™ Power Section Specification (Metric)
500ERTcr6780
127 mm 6:7 Lobes 8.0 Stages
Rotor Specifications
Overall Length 6070.6 mm
Avg. Diameter 66.93 mm
Contour Length 5918.2 mm
Eccentricity 4.86 mm
Major Diameter 76.66 mm
Head Diameter 73.66 mm
Head Length 152.4 mm
Weight 166 kg
Thread Form 2 3/8" HEF
Stator Specifications
Overall Length 6248.4 mm
Tube OD 127.00 mm
Contour Length 5778.5 mm
Tube ID 82.17 mm
Rubber Cut-back
Side 1: 190.5 mm
Side 2: 279.4 mm
Weight 248 kg
Material Alloy Steel
Performance Specifications
Flow Range 568-1325 LPM
Rev per Unit Volume 0.21 Rev/L
Speed Range 117-274 RPM
No Load Pressure Loss 1365 kPa
  POB XTH
Max Rec Press 14,720 kPa 15,790 kPa
Torque @ Max Press 8,950 N-m 9,590 N-m
Stall Pressure 26,940 kPa 28,890 kPa
Stall Torque 18,240 N-m 19,570 N-m
Stator Minors and Fit (mm) at 21°C
  XTH POB
Group Minor Fit Minor Fit
T 66.98 -0.05
0 67.21 -0.28 67.21 -0.28
5 67.56 -0.64 67.56 -0.64
7 67.82 -0.89
 
Reline Lengths (mm) Max 6248 Min 6096
Alt. Stator OD (mm)   -   -
Alt. Rotor Diameter (mm) 66.980 - - -

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

Torque
Differential Pressure (kPa) 0 20,000 Torque (Nm) 0
Fit Increase
Change in Temperature (°C) 0 50 100 150 Fit Increase (mm) 0
Speed
Differential Pressure (kPa) 0 10,000 20,000 Speed (RPM) 0
Mechanical Power
Differential Pressure (kPa) 0 20,000 Mechanical Power (Kw) 0
Torque
Differential Pressure (kPa) 0 5,000 10,000 15,000 20,000 Torque (Nm) 0 5,000 10,000 15,000
Fit Increase
Change in Temperature (°C) 0 20 40 60 80 100 120 140 160 180 Fit Increase (mm) 0 0.5 1
Speed
568 LPM 946 LPM 1325 LPM Differential Pressure (kPa) 0 5,000 10,000 15,000 20,000 Speed (RPM) 0 100 200 300
Mechanical Power
568 LPM 946 LPM 1325 LPM Differential Pressure (kPa) 0 5,000 10,000 15,000 20,000 25,000 Mechanical Power (Kw) 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.