Circulating Subs

Circulating Subs
Crossover Subs
Drillable Lifting Subs
Drill Pipe Pup Joints
Kelly Saver Subs
Lift Nubin
Lifting Subs
Lower Kelly Valves
Side Entry Subs (Integral)
Side Entry Subs (Welded)
Upper Kelly Valves
image of circulating subs from Downhole Oil Tools
Circulating subs are are manufactured from AISI 4140/4145 alloy steel with one pin up
connection to match the drill pipe by a 2” 1502 union.

When ordering, please specify:

  • Overall length; 15” standard

  • Sub OD

  • Sub Bore

  • Connection size (ex. 3-1/2” API IF, NC-38)