API 5CT tubing with factory-applied internal HDPE or EXPE (cross-linked polyethylene) liner for corrosion-resistant service. The liner provides H₂S and CO₂ chemical resistance and reduces rod-on-tubing wear in beam-pumped wells. Host pipe sizes, liner thickness, and resin grade are quoted per project requirements.
Procurement Note
Liner thickness, resin grade, and confirmed host pipe sizes are quoted per project. Contact ZC with service temperature, fluid composition, and pressure requirements.
Host Pipe
Standard: API 5CT
Sizes: 2⅜″, 2⅞″, 3½″, 4½″ (contact for specific size availability — host pipe sizes confirmed per project)
Liner: HDPE or EXPE (cross-linked PE) per manufacturer specification
Operating Limits
Max temp (oil production): 71°C (160°F)
Max temp (aqueous service): 82°C (180°F)
Lining Material Performance
Property
Value
Density
0.94 – 0.97 g/cm³
Vicat softening temperature
≥ 130°C
Notched impact strength (simply supported)
≥ 50 kJ/m²
Tensile yield strength
≥ 20 MPa
Shore hardness
≥ 65 HD
Tensile elongation at break
≥ 400%
Applications
→Oil production wells with rod wear and scaling — liner reduces sucker rod friction and prevents scale buildup on tubing ID
→Corrosive gas wells — HDPE liner provides resistance to H₂S and CO₂ gas corrosion
→Water injection wells with serious corrosion and scaling — liner prevents scale-induced flow restriction
→Old pipe repair and repurposing — severely corroded or worn oil pipes lined and returned to service as flow lines
→Transmission pipe — aged tubing unsuitable for downhole service reused as surface oil delivery pipe after lining
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
L80-3Cr
552–655 / 80–95
655 / 95
23 HRC
Q+T only
L80-9Cr
552–655 / 80–95
655 / 95
23 HRC
Q+T only
L80 13Cr
552–655 / 80–95
655 / 95
23 HRC
Q+T only
R95
655–758 / 95–110
724 / 105
—
Q+T only
C90
621–724 / 90–105
689 / 100
25.4 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
758–828 / 110–120
793 / 115
29.0 HRC
Q+T only
Q125
862–1034 / 125–150
931 / 135
None
Q+T only
API 5CT grades manufactured and supplied 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
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, L80-3Cr, R95, C90, T95, P110
Production casing / tubing
5
127.0
11.50–18.00
6.43–9.19
N80, L80, L80-3Cr, R95, C90, T95, P110, C110
Production casing
5½
139.7
14.00–23.00
6.98–10.54
N80, L80, L80-3Cr, R95, C90, T95, P110, C110
Production casing — most common
7
177.8
17.00–38.00
6.91–14.27
N80, L80, R95, C90, T95, P110
Intermediate / production casing
7⅝
193.7
24.00–45.30
8.33–15.11
N80, L80, R95, T95, P110, C110
Intermediate casing
9⅝
244.5
32.30–58.40
8.94–15.11
N80, L80, R95, T95, P110, C110
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, L80-3Cr, T95, P110
2⅞
73.0
6.40–10.40
5.51–7.82
J55, N80, L80, L80-3Cr, C90, T95, P110, C110
3½
88.9
7.70–12.95
5.49–8.31
J55, N80, L80, L80-3Cr, T95, P110
4
101.6
9.50–14.00
5.74–8.38
N80, L80, L80-3Cr, C90, T95, P110, C110
4½
114.3
12.60–26.10
6.88–16.00
N80, L80, L80-3Cr, C90, 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.
HDPE-lined tubing — finished pipe sections with flanged ends
HDPE-lined tubing — installation
HDPE liner material — pre-installation
HDPE-lined steel pipe — warehouse
HDPE-lined tubing — flange end detail
Procurement Note
Liner thickness, resin grade, and confirmed host pipe sizes are quoted per project. Contact ZC with service temperature, fluid composition, and pressure requirements for a project-specific specification.
→ Oil production wells with rod wear and scaling
The HDPE liner reduces sucker rod friction and resists scale buildup on the tubing ID. Suitable for wells with high sucker rod failure rate and eccentric wear from deviated wellbore geometry.
→ Corrosive gas wells (H₂S and CO₂ service)
HDPE liner provides chemical resistance to H₂S and CO₂ corrosion that would otherwise attack bare steel tubing ID. Maintains integrity in wells where gas-phase corrosion is the primary degradation mechanism.
→ Water injection wells with corrosion and scaling
Suitable for injection wells where aggressive injection water chemistry (high TDS, biogenic sulfate, dissolved oxygen) causes accelerated corrosion and scale formation on bare steel tubing.
→ Old pipe repair and repurposing
Severely corroded or worn oil pipes can be HDPE-lined and returned to service, reducing oil production costs while extending service life. Pipe must retain structural integrity to serve as the host.
→ Transmission pipe (surface application)
Old oil pipes with severe corrosion and eccentric wear that are unsuitable for downhole use can be lined and repurposed as surface oil delivery pipes.
