OCTG distributors operate in one of the highest-stakes cert environments in the steel supply chain. A rejected casing or tubing string at the well site is not an inconvenience — it's a well intervention. The cost of pulling and replacing a rejected string, the rig time, and the lost production easily exceed the value of the pipe itself. The cert mistakes that cause these rejections are consistent, and they're almost always the same five issues.
None of these are difficult to fix. They all have the same structural cause: delivery cert packages assembled without a standardized checklist that reflects what operators actually require at receiving inspection.
Mistake 1: PSL Level Not Specified on the Cert
Both API 5L and API 5CT have PSL 1 and PSL 2 variants. For sour service (H₂S-containing environments governed by MR0175/ISO 15156) and for most offshore applications, PSL 2 is mandatory. PSL 2 adds chemistry restrictions, tighter mechanical property windows, and additional inspection requirements not present in PSL 1.
A cert that shows the grade — L80, P110, X65 — but does not explicitly state the PSL level is incomplete. Operator receiving inspectors at oilfield facilities routinely reject these documents. They have no basis for confirming PSL 2 compliance from a cert that doesn't state it.
This failure is preventable at the time of mill order. The PO to the mill must specify PSL level. At incoming receiving, verify that PSL level appears on the cert before accepting to stock.
Mistake 2: Missing Heat Treatment Condition for Sour Service
API 5CT sour service grades — L80 Type 1, C90, T95, P110 special — require specific heat treatment conditions for compliance with MR0175/ISO 15156. These conditions (normalized, quenched and tempered, or normalized and tempered depending on grade) affect hardness and hydrogen sulfide cracking resistance.
The cert must state the heat treatment condition. Mill certs for non-sour grades of the same nominal material type routinely omit this because it isn't required for non-sour applications. When a sour service cert arrives without the heat treatment condition stated, the operator's receiving inspector has no documentary evidence of MR0175 compliance. The pipe is held.
Mistake 3: No Hardness Test Results for Sour Service
API 5CT sour service grades require hardness testing with acceptance limits specified by grade. The cert must include the hardness values — Rockwell HRC or equivalent — for the tested pipe. Compliance with MR0175/ISO 15156 hardness limits is a documentary requirement; the operator cannot accept the pipe without this data.
Standard certs for non-sour grades do not include hardness test results because the testing isn't required. When a distributor relays a non-sour-format cert for sour service material, the hardness data is absent. The receiving inspector puts the pipe on hold.
Mistake 4: Threading Cert Not Included
If the distributor supplies threaded OCTG — with API round thread, buttress, or premium connections — the threading inspection cert must accompany the pipe mill cert. The threading cert documents: thread form compliance, tally (measured length), and drift test results (confirming minimum bore).
Many distributors relay the pipe mill cert but not the threading cert. These are two separate documents from two separate sources — the pipe mill issues the base pipe cert, and the threading facility (which may be the mill, the distributor's own threading operation, or a third-party facility) issues the threading cert. Both must be in the delivery package.
When the threading cert is absent, the operator cannot confirm thread form compliance or drift. The shipment is held.
Mistake 5: No PMI Results for Premium Connection Joints
Some operators require positive material identification (PMI) results for premium connection joints — particularly for high-alloy grades (13Cr, super 13Cr, duplex) and for critical well applications. PMI results come from X-ray fluorescence or optical emission spectroscopy testing of the actual connection material, not from the mill cert chemistry.
PMI certs are separate from the pipe mill cert. They come from the connection manufacturer, the threading facility, or the distributor's own PMI testing. When an operator specifies PMI and it's absent from the delivery package, the shipment is rejected at the wellsite — often after the pipe has been transported to a remote location.
The Fix: A Delivery Cert Checklist Specific to OCTG
The common cause of all five mistakes is the same: delivery cert packages assembled without a checklist that reflects the full set of documents operators require for the specific product and application.
A compliant OCTG delivery cert package for sour service material includes:
- API 5L or 5CT mill cert with PSL level stated
- Heat treatment condition per grade sour service requirement
- Hardness test results (for applicable grades)
- Threading inspection cert (when threaded pipe is supplied)
- PMI cert (when specified by the operator's PO)
Each item has a status: received from source / verified against requirement / included in delivery package. The checklist is completed before the shipment leaves the warehouse — not after the operator's receiving inspector calls with a rejection.