Integral-joint tubing upsetting at one end, external threading, and external upsetting at the other end, internal threading. API integral-joint tubing is on the market in OD dimensions of 1.315 to a couple of.063 inch.

API integral-joint tubing provides 10-round form together with a joint strength which is less than the body minimum yield, this reduces its use.

The small OD of integral-joint tubing enables its use inside of larger tubing strings or inside of wells as unloading or vent strings.

The couplings will need to meet all the minimum specifications outlined in API Spec. 5CT. API Spec. 5B3 and API RP 5B14 cover threading, gauging, and thread inspection.

Specifications

Tolerances

Mechanical Properties

Inspection

Physical properties are checked and each length hydrostatically tested, normally to only 3,000 psi in the plain end (unthreaded) condition. The following are also checked:

• Dimensions
• Weights
• Straightness
• Lengths

Part of this inspection is to drift all lengths.
Despite all the American Petroleum Institute (API) specifications and testing, some tubing defects are still found after delivery; thus, some operators do further inspection.

Inspection Method

• Size and surface inspection
• NDT and pressure test and third party certication
• Hydrostatic
• Drifting test
• Physical and chemicail analysis
• Hardness and pressure test.
• Electromagnetic
• Magnetic particle
• Ultrasonic