Name: Welded Line Pipe — ERW / LSAW / SSAW
Brand: ZC Steel Pipe

Standard

API 5L / ISO 3183, DNV-ST-F101, NACE MR0175 / ISO 15156, NACE TM0284 (HIC testing)

Grades

5 grades

Size Range

2" – 60" OD · ERW / LSAW / SSAW · PSL1 & PSL2

Applications

Standards & Certifications

API 5CT / ISO 11960 — Specification for Casing and Tubing — all grades
NACE MR0175 / ISO 15156 — Sour service qualification — L80, T95, C110
API 5C5 — Connection performance qualification
API TR 5C3 — Collapse, burst and tensile load calculations
EN 10204 3.1 / 3.2 — Mill test certificate documentation

Connection Types

STC — Short Round Thread

API

Standard API. Shallow, low-pressure surface casing.

LTC — Long Round Thread

API

Higher tensile efficiency than STC. Moderate depth intermediate casing.

BTC — Buttress Thread

API

High collapse and tensile capacity. Standard for N80, L80, T95 and moderate-depth P110.

Premium Connections

ZC Patent

Metal-to-metal seal. Required for HPHT, deep wells, P110/Q125 and gas-tight applications. ZC-patented.

Physical & Mechanical Properties

Property	Value / Range

API 5CT Mechanical Requirements by Grade

Grade	Min–Max Yield MPa / ksi	Min Tensile MPa / ksi	Max Hardness	Heat Treatment
H40	276–552 / 40–80	414 / 60	—	None required
J55	379–552 / 55–80	517 / 75	—	None required
K55	379–552 / 55–80	655 / 95	—	None required
N80-1	552–758 / 80–110	689 / 100	—	Normalise or Q+T
N80Q	552–758 / 80–110	689 / 100	—	Q+T only
L80-1	552–655 / 80–95	655 / 95	23 HRC	Q+T only
L80 13Cr	552–655 / 80–95	655 / 95	23 HRC	Q+T only
T95	655–758 / 95–110	724 / 105	25.4 HRC	Q+T only
P110	758–965 / 110–140	862 / 125	None	Q+T only
C110	758–965 / 110–140	793 / 115	30 HRC	Q+T only
Q125	862–1034 / 125–150	931 / 135	None	Q+T only

API 5CT grades stocked and manufactured by ZC Steel Pipe. Grade selection is driven by well depth, H₂S environment, and pressure containment requirements.

Grade	Yield MPa / ksi	Tensile MPa / ksi	Max Hardness	H₂S Service	Typical Application

Sour Service Grade Selection

Procurement Note — H₂S Grade Selection Never substitute P110 or Q125 for a sour-service grade based on cost or availability pressure. NACE MR0175 hardness limits exist to prevent sulphide stress cracking — a brittle fracture mode with no ductile warning in H₂S environments. The correct escalation path is L80 → T95 → C110 depending on H₂S partial pressure and well depth.

Condition	Correct Grade
Mild sour, moderate pressure	L80-1 PSL-2 (+ SR16 HIC test if required)
Moderate sour, high pressure	T95 Type 2 PSL-2 with NACE qualification
Severe sour, high pressure / HPHT	C110 PSL-2 with full NACE + Charpy
Deep HPHT, sweet (no H₂S)	P110 PSL-2 or Q125 PSL-2

Technical Guides for Each Grade

API 5CT casing and tubing dimensions and weight chart. Common sizes from 4½″ to 20″ casing and 1.050″ to 4½″ tubing — OD, wall thickness, weight range, and applicable grades per API 5CT. Contact us to confirm availability for specific size/grade combinations.

Casing — Common Sizes

OD (in)	OD (mm)	Weight Range (lb/ft)	Wall Range (mm)	Common Grades	Typical String
4½	114.3	9.50–15.10	5.21–8.56	N80, L80, T95, P110	Production casing / tubing
5	127.0	11.50–18.00	6.43–9.19	N80, L80, T95, P110	Production casing
5½	139.7	14.00–23.00	6.98–10.54	L80, T95, P110, C110	Production casing — most common
7	177.8	17.00–38.00	6.91–14.27	N80, L80, T95, P110	Intermediate / production casing
7⅝	193.7	24.00–45.30	8.33–15.11	L80, T95, P110, C110	Intermediate casing
9⅝	244.5	32.30–58.40	8.94–15.11	N80, L80, P110	Intermediate casing
10¾	273.1	32.75–65.70	7.09–13.84	J55, K55, N80	Surface casing
13⅜	339.7	48.00–72.00	8.38–12.19	J55, K55, N80	Surface casing
16	406.4	65.00–109.00	9.53–15.88	J55, K55	Conductor / surface
20	508.0	94.00–133.00	11.13–15.88	H40, J55	Conductor pipe

Tubing — Common Sizes

OD (in)	OD (mm)	Weight Range (lb/ft)	Wall Range (mm)	Common Grades
1.050	26.7	1.14–1.80	2.41–3.91	J55, N80
1.315	33.4	1.70–2.90	2.90–4.55	J55, N80
1.660	42.2	2.30–3.40	2.90–4.85	J55, N80
1.900	48.3	2.75–4.70	3.18–5.08	J55, N80, L80
2⅜	60.3	4.00–6.40	3.18–5.54	J55, N80, L80, T95, P110
2⅞	73.0	6.40–10.40	5.51–7.82	J55, N80, L80, T95, P110, C110
3½	88.9	7.70–12.95	5.49–8.31	J55, N80, L80, T95, P110
4	101.6	9.50–14.00	5.74–8.38	N80, L80, T95, P110
4½	114.3	9.50–15.10	5.21–8.56	N80, L80, T95, P110, C110

Procurement Note — Size Confirmation The tables above show common API 5CT sizes. Not every size/grade combination is held in stock — ZC Steel Pipe is order-to-make. Send us your full specification (OD, weight, grade, connection, PSL, quantity) and we will confirm availability and lead time within one business day.

All ZC Steel Pipe casing and tubing is tested and documented per API 5CT. PSL-2 orders include mandatory NDE and impact testing. Third-party inspection to EN 10204 3.2 available on request.

PSL-1 vs PSL-2 Testing Requirements

Requirement	PSL-1	PSL-2
NDE — pipe body	Not mandatory	Full-length UT or EMI
NDE — pipe ends	Not mandatory	Mandatory UT
Charpy impact test	Not mandatory	Mandatory per Table C.36
Dimensional tolerance	Standard API	Tighter OD, wall, straightness
Traceability	Heat number	Heat + pipe number per joint
Hardness survey (SR15)	Optional	Required for NACE qualification
MTC format	EN 10204 3.1 typical	EN 10204 3.1 or 3.2
Recommended for	Sweet wells, shallow depth	All sour service; HPHT; IOC projects

Supply Enquiry — Casing & Tubing

Tell us your grade, OD, weight, connection, PSL level and delivery port. We will respond within one business day with availability and lead time.

Request a Quote

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Welded Line Pipe — ERW / LSAW / SSAW