ERT™ Power Section Specification
500ERTcr7838
5" 7:8 Lobes 3.8 Stages
Rotor Specifications
Overall Length 178.00 in
Avg. Diameter 2.607 in
Contour Length 172.00 in
Eccentricity 0.164 in
Major Diameter 2.936 in
Head Diameter 2.750 in
Head Length 6.00 in
Weight 234 lb
Thread Form 2 3/8" HEF
Stator Specifications
Overall Length 187.00 in
Tube OD 5.00 in
Contour Length 171.00 in
Tube ID 3.176 in
Rubber Cut-back
Side 1: 8.00 in
Side 2: 8.00 in
Weight 435 lb
Material Alloy Steel
Performance Specifications
Flow Range 150-325 GPM
Rev per Unit Volume 0.51 Rev/Gal
Speed Range 76-166 RPM
No Load Pressure Loss 234 psi
  POB XTH
Max Rec Press 1,050 psi 1,130 psi
Torque @ Max Press 5,420 ft-lbs 5,810 ft-lbs
Stall Pressure 1,920 psi 2,060 psi
Stall Torque 9,920 ft-lbs 10,630 ft-lbs
Stator Minors and Fit (in) at 70°F
  XTH POB
Group Minor Fit Minor Fit
T 2.613 -0.006 2.613 -0.006
0 2.623 -0.016 2.623 -0.016
4 2.638 -0.030 2.638 -0.030
 
Reline Lengths (in) Max 187 Min 181
Alt. Stator OD (in)   5.000   -
Alt. Rotor Diameter (in) - 2.620 - 2.593

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 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 Mechanical Power (hp) 0
Torque
Differential Pressure (psi) 0 500 1,000 1,500 Torque (ft-lb) 0 2,000 4,000 6,000 8,000
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
150 GPM 238 GPM 325 GPM Differential Pressure (psi) 0 500 1,000 1,500 Speed (RPM) 0 50 100 150 200
Mechanical Power
150 GPM 238 GPM 325 GPM Differential Pressure (psi) 0 500 1,000 1,500 Mechanical Power (hp) 0 100 200 300
©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.