Crossover (Tubing & Casing): Field Notes, Specs, and Sourcing

When you’re marrying different thread types in a completion string, you reach for a tubing crossover. Simple idea, critical job. This model—Crossover—from Hengshui Weijia Petroleum Equipment Manufacturing Co., Ltd., is a small component with outsized consequences for sealing integrity and make-up torque. And yes, I’ve seen projects saved (and a few delayed) by getting this detail right.

Industry trend check: more premium connections, more corrosive service (think sour gas/CO₂), and a steady uptick in geothermal and UGS. That means higher demands on tubing crossover metallurgy, thread gauging, and surface finish. Actually, many customers say lead time and traceability are now as decisive as price.

Technical snapshot (Crossover)

Process flow and QA (how it’s actually made)

• Materials: Forged blanks (4130/4140 or CRA). Heat-treated (Q&T) to grade; full traceability via heat numbers.
• Machining: CNC turning, thread cutting per API 5B/premium license specs; critical tolerances checked with calibrated gauges.
• Finishing: Phosphating, thread dope, protectors; clean-pack for rig readiness.
• Testing standards: Hydrostatic proof typically ≈ 1.1–1.5× working pressure; UT/MPI on stress areas; hardness 197–237 HBW for L80-type ranges (example).
• Service life: Around 3–10 years depending on load cycles, corrosion regime, make-up control, and inhibitor program.
• Industries: Oil & gas upstream, workover, geothermal (to ~180°C), UGS, CO₂/CCUS pilots.

Where a tubing crossover shines

• Mixing legacy tubing with new premium casing without rethreading.
• Workover tie-ins after partial string replacements.
• Sour or CO₂ lines needing 13Cr/CRA ends only where necessary (cost control).

Vendor snapshot (indicative)

Real-world use, briefly

• Middle East sour gas: L80-13Cr tubing crossover EUE↔BTC; hydro test 12,500 psi; zero leak across 10 make/breaks.
• North America geothermal: 22Cr sleeve on hot end; held torque after 180°C cycling; drifted clean on pullback.

Customer feedback? “Fits first time” comes up a lot. To be honest, that’s usually down to disciplined thread gauging and clean packing, not magic.

Customization and data

• Custom thread pairs (API↔premium), special lengths, CRA cladding or full CRA.
• Test data (typical sample): hydro proof 1.25× WP; tensile to parent grade min; hardness for L80 ≈ 207 HBW average; UT/MPI 100% on stress radii.
• Certifications: ISO 9001 QMS; materials qualified to ISO 15156 for sour service; threading per API 5B; conforms to API 5CT dimensions.

Buying tip

Share both connection drawings (pin/box), target make-up torque, and service fluid. It seems basic, but it prevents 80% of field hiccups with tubing crossover installs.

References

1. API Specification 5CT – Casing and Tubing.
2. API Specification 5B – Threading, Gauging, and Inspection of Casing, Tubing, and Line Pipe Threads.
3. ISO 15156 (NACE MR0175) – Materials for use in H2S-containing environments.
4. ISO 9001:2015 – Quality Management Systems.