Replacing studs one at a time on a live flange is now covered by a new PCC-1-2026 Appendix G. Before that work is considered, the owner checks for conditions that rule it out. This page summarizes those checks. It is a pre-check, not a procedure. A printable PDF (PB-TD-221) is below. Values are for reference; confirm against the current edition of the governing standard. Send us your bolting list for a quote or call (281) 581-0176.
Related: Bolt and Nut Reuse Guide · Sour Service Bolting Quick Reference · Relaxation and Retorque Passes · All technical docs
Stop: conditions that rule out SSR (Table G-6-1, paraphrased)
- Studs next to the one being replaced are corroded below the limit in App G.
- Bolting is susceptible to environmental cracking, for example B7 in caustic, hydrogen or sulfide service.
- Compressed fiber or organic-binder sheet gaskets, which can be brittle.
- The system is in a transient condition.
- Tapped holes with short effective length, unless the user approves.
- Cryogenic service is generally not recommended.
Basic rules (G-3, G-4)
- A risk assessment team decides. App G gives a scoring method for likelihood of leakage.
- Never have more than one stud out at a time. Finish each stud once started.
- At least 8 bolts, unless analysis or a clamp supports fewer.
- For a leak, turn-of-nut tightening is the first option before SSR.
- Use new studs for on-stream leak work; reuse only cleaned and inspected studs otherwise.
- Hydraulic tools can be problematic above 212°F.
What Patriot Bolt supplies
Patriot Bolt manufactures replacement stud bolts, heavy hex nuts and washers to your specification. We do not perform stud replacement, hot bolting or any field bolting work.
References: ASME PCC-1-2026, Guidelines for Pressure Boundary Bolted Flange Joint Assembly. Summaries are paraphrased; clause numbers refer to ASME PCC-1-2026 unless noted. Patriot Bolt manufactures bolting and does not perform bolting, training or joint assembly services.