ZC Steel Pipe — 桢诚钢铁

Technical Articles

Engineering guides, grade selection resources and technical references for oil and gas professionals. Written for procurement managers and engineers specifying API-grade steel pipe.

Not sure which grade fits your project? Enter your well or pipeline conditions — our AI recommends grade, PSL level and connection type.

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General

Steel Pipe Weight Calculation: Formula, Chart, and Worked Examples

Calculate steel pipe weight by size and schedule. ASME B36.10M formula, worked examples, and weight chart for NPS 2–24 carbon steel pipe.

June 28, 2026 Read article →
General

Schedule 40 vs Schedule 80 Pipe: Wall Thickness, Pressure Rating, and Cost

Schedule 40 vs Schedule 80 pipe: same OD, different wall. ASME B36.10M dimensions NPS 2–10, pressure ratings, cost difference, and when to specify eac…

June 28, 2026 Read article →
General

NDT of Steel Pipe: Methods, API Requirements, and What to Specify

UT, MT, PT, ET — what each NDT method detects, when API 5CT and API 5L require it by grade, acceptance criteria, and how to write a complete NDE purch…

June 28, 2026 Read article →
Line Pipe

LSAW vs SSAW Pipe: Differences, Applications, and When to Specify Each

LSAW vs SSAW pipe: manufacturing, OD range, dimensional tolerance, weld geometry, and when each is specified for API 5L pipelines. Includes PO guidanc…

June 28, 2026 Read article →
13Cr / CRA

L80 Type 1 vs L80-13Cr vs L80-9Cr: OCTG Grade Selection for Corrosive Wells

L80 Type 1 is the sour-service grade. L80-13Cr and 9Cr resist CO2 — but fail in H2S. API 5CT 11th edition selection guide for corrosive wells.

June 28, 2026 Read article →
OCTG

How to Choose an API Oil Casing Pipe Manufacturer: A Procurement Guide

A guide to evaluating Chinese API 5CT casing mills — what to verify on the RFQ, what documents to request, and the red flags that precede a bad shipme…

June 28, 2026 Read article →
Line Pipe

What Type of Steel Is Used in Oil Pipelines? Grade and Standard Guide

What type of steel is used in oil and gas pipelines? API 5L X52–X80 grades, PSL1 vs PSL2, sour service Annex H, and manufacturing method selection gui…

June 19, 2026 Read article →
OCTG

P110 Casing Procurement Guide: TCO and Running Cost Analysis

P110 casing procurement: PO language, yield histogram trap, MTC verification checklist, and TCO vs N80Q and Q125. HPHT well sourcing guide.

June 19, 2026 Read article →
OCTG

H40 Casing in Shallow and Water Wells: Applications and Limits

H40 casing specifications, applications in shallow and water wells, and the exact load conditions where H40 fails. API 5CT procurement guide.

June 19, 2026 Read article →
OCTG

Deepwater Drilling Pipe — Materials, Coatings, and Connection Challenges

Deepwater drill pipe material selection, collapse rating, fatigue management, IPC coatings, and double-shouldered connections. API 5DP G105 and S135 g…

June 19, 2026 Read article →
Connections

API Couplings — OCTG Threaded Connection Specifications and Selection

API couplings for OCTG: STC, LTC, BTC specifications, grade matching rules, sour service coupling selection, and procurement guide. ZC Steel Pipe.

June 19, 2026 Read article →
Line Pipe

X52 vs X60 vs X65 Line Pipe: Grade Selection Guide for Medium-Pressure Pipelines

API 5L X52, X60, and X65 line pipe grade comparison. Wall thickness design, PSL1 vs PSL2, delivery conditions, and procurement guidance for pipeline e…

June 17, 2026 Read article →
OCTG

Q125 in Ultra-Deep HPHT Wells: Design Limits and Procurement Guide

Q125 casing for ultra-deep HPHT wells: API 5CT Group 4 requirements, burst and collapse design examples, SSC exclusion, and procurement pitfalls vs P1…

June 17, 2026 Read article →
Connections

Galling in 13Cr and CRA Connections: Causes, Diagnosis, and Prevention

Why 13Cr and CRA connections gall during makeup, how to identify galling in the field, and which thread compounds and running procedures prevent it.

June 17, 2026 Read article →
13Cr / CRA

Duplex vs 13Cr vs Incoloy 825: CRA Selection for HPHT Sour Wells

22Cr duplex, 2507 super duplex, L80-13Cr, and Incoloy 825 for HPHT sour wells. H₂S limits, FPREN, and procurement guidance per NACE MR0175 / ISO 15156…

June 17, 2026 Read article →
OCTG

Casing String Design for EPC Engineers: Step-by-Step Guide

Step-by-step casing string design for EPC engineers. Grade selection, collapse, burst and tension load analysis with worked calculations.

June 17, 2026 Read article →
Line Pipe

API 5L Line Pipe for Natural Gas Transmission: Grade and Wall Thickness Guide

Select the right API 5L grade and wall thickness for gas transmission. X52 vs X65 vs X70 PSL2, ASME B31.8 design examples, sour gas Annex H.

June 17, 2026 Read article →
Heat Exchanger

U-Tube, Fire-Tube, and Water-Tube Heat Exchangers: Engineering Comparison

U-tube, fire-tube, and water-tube heat exchanger engineering comparison. Tube material selection, TEMA standards, and procurement guide.

June 16, 2026 Read article →
13Cr / CRA

Super 13Cr in CO2-H2S Mixed Environments — When It Fails and What to Use

Super 13Cr failure limits in CO2-H2S wells: SSC risk, H2S partial pressure thresholds, temperature limits, and when to specify duplex or nickel CRA in…

June 16, 2026 Read article →
OCTG

J55 vs K55 Casing — Surface and Intermediate Casing Field Selection Guide

J55 vs K55 casing: same yield strength, different tensile, different connections. When to use J55 STC/LTC vs K55 BTC for surface and intermediate stri…

June 16, 2026 Read article →
Heat Exchanger

Heat Exchanger Tube Cleaning and Scaling: Maintenance Guide

Scaling, fouling, and cleaning guide for heat exchanger tubes. Hydroblasting, chemical descaling, TEMA fouling factors, and fin tube maintenance.

June 16, 2026 Read article →
Heat Exchanger

Finned Tube Manufacturers and Suppliers: Procurement Guide

How to source and evaluate finned tube manufacturers. What to specify on a PO, MTC requirements, API 661 compliance, and red flags in supplier qualifi…

June 16, 2026 Read article →
Heat Exchanger

Bimetallic and Copper-Nickel Fin Tubes for Corrosive Service

Bimetallic and cupro-nickel fin tubes for corrosive and marine service. ASTM B111 Cu-Ni alloys, selection guide, and procurement tips.

June 16, 2026 Read article →
Coatings

Abrasion Resistant Coating for Slurry and Multiphase Pipelines

Abrasion resistant pipe coatings for slurry and multiphase service: ceramic epoxy, RFBE, polyurethane, HDPE liner. Selection guide with specs and stan…

June 16, 2026 Read article →
OCTG

P110 vs L80 Casing — Why Use P110 Instead of L80 and When Not To

P110 vs L80 casing: yield strength, sour service limits, connection requirements, cost, and when to upgrade from L80 to P110. API 5CT selection guide.

June 13, 2026 Read article →
OCTG

L80 vs T95 Casing: When to Upgrade in Sour Gas Wells

L80 covers 80–95 ksi yield for mild sour wells; T95 upgrades to 95–110 ksi for deeper H2S applications. Grade selection guide per API 5CT and NACE MR0…

June 13, 2026 Read article →
Heat Exchanger

Finned Tubes: Types, Manufacturing, and Heat Exchanger Applications

Complete guide to finned tubes — extruded, welded, and crimped types, base tube and fin materials, API 661 dimensions, and heat exchanger applications…

June 13, 2026 Read article →
Heat Exchanger

Fin Spacing and Heat Exchanger Efficiency: Engineering Guide

Engineering guide to fin pitch selection — how fin spacing affects heat transfer, air-side pressure drop, fouling tolerance, and fin surface efficienc…

June 13, 2026 Read article →
Heat Exchanger

Extruded vs Welded vs Crimped Fin Tubes: Manufacturing Comparison

Compare extruded, HF-welded, and crimped fin tube manufacturing — bond type, max service temperature, fouling resistance, and when to specify each.

June 13, 2026 Read article →
Connections

Casing Connection Types: STC, LTC, BTC and Premium — Selection Guide

STC, LTC, BTC and premium casing connections — tensile efficiency, gas sealing, sour service, and selection by well type. Quote from ZC Steel Pipe.

June 13, 2026 Read article →
Connections

BTC vs Premium Connections — Casing & Tubing Selection Guide

BTC vs premium connections: when to upgrade, metal-to-metal seal, API 5C5 CAL IV, gas-tight requirements, HPHT and sour service. Request a quote.

June 13, 2026 Read article →
Connections

BTC Make-Up Torque: API 5C1 Reference for 4½" to 13-3/8" Casing

BTC casing make-up torque from API 5C1: full table for 4½" to 13-3/8", friction factor adjustment for non-standard compounds, and field troubleshootin…

June 13, 2026 Read article →
Line Pipe

API 5L X80 Line Pipe — Specifications & Ultra-High Strength Guide

X80 line pipe: 555 MPa yield, PSL2, LSAW large diameter, X80 vs X70, strain-based design. Full MTC. Request a quote from ZC Steel Pipe.

June 13, 2026 Read article →
Line Pipe

API 5L X60 Line Pipe — Specifications, PSL1 & PSL2 Guide

X60 line pipe: 415 MPa yield, PSL1 vs PSL2, seamless and welded, sour service HIC, sizes and wall thickness. Full MTC. Request a quote.

June 13, 2026 Read article →
Line Pipe

API 5L Grade B Pipe: PSL1 and PSL2 Specifications

API 5L Grade B (L245) line pipe: PSL1 and PSL2 specifications, chemistry, Charpy toughness, and delivery conditions. Mill supplier for Africa and Midd…

June 13, 2026 Read article →
OCTG

API 5CT R95 Casing Pipe — Specifications, Grade Position & Selection

R95 casing: 95 ksi yield, Q+T, sweet service. Full mechanical properties, chemistry, R95 vs T95 vs P110 comparison. PSL-2. Request a quote from ZC.

June 13, 2026 Read article →
OCTG

API 5CT Q125 Casing Pipe — Specifications, Types & Application Guide

Q125 casing pipe: API 5CT specs, Type 1–4 subtypes, Q125 vs C110 vs P110, deep well applications. Seamless Q125 supplier. Request a quote from ZC Stee…

June 13, 2026 Read article →
OCTG

The Hardness Trap — API 5CT Limits vs NACE MR0175 for Sour Service Casing

API 5CT hardness limits vs NACE MR0175 for sour service casing: the 22 HRC vs 23 HRC gap, T95 Type 1 trap, HAZ hardness, and how to specify correctly.

June 13, 2026 Read article →
OCTG

API 5CT C90 Casing Pipe — Sour Service Specifications & Selection

C90 casing: 90 ksi yield, 25.4 HRC max, sour service approved. Specs, C90 vs L80 vs T95, chemistry, NACE MR0175 guidance. PSL-2. Request a quote.

June 13, 2026 Read article →
OCTG

API 5CT C110 Casing Pipe — Specifications, Sour Service & Supplier Guide

C110 casing pipe: API 5CT specs, hardness limits, NACE MR0175 sour service compliance, C110 vs T95 vs Q125 comparison. Request a quote from ZC Steel P…

June 13, 2026 Read article →
OCTG

Production Tubing Selection for Oil and Gas Wells: Grade and Size Guide

Select production tubing grade and size for oil and gas wells: N80Q, L80, T95, and 13Cr options, connection types, and procurement checklist per API 5…

June 11, 2026 Read article →
OCTG

N80-1 vs N80Q Casing: Heat Treatment Differences and When to Specify Each

N80-1 allows normalizing or Q+T; N80Q mandates Q+T only. Compare heat treatment, toughness, and procurement guidance per API 5CT 11th Edition.

June 11, 2026 Read article →
OCTG

Oilfield Pipe Overview: OCTG, Drill Pipe, Line Pipe, and Coated Pipe

Overview of oilfield pipe types: OCTG casing and tubing, drill pipe, line pipe, and coated systems. Grade selection and supplier guide for EPC enginee…

June 6, 2026 Read article →
Boiler Tube

Boiler Tube Leaks: Diagnosis, Repair, and Prevention Field Guide

Field guide to diagnosing, repairing, and preventing boiler tube leaks. Covers pressure testing, weld repair, tube plugging, and replacement material …

June 6, 2026 Read article →
Boiler Tube

Boiler Tube Coatings: Ceramic, Cladding, and Weld Overlay Protection

Guide to boiler tube protection coatings: ceramic thermal sprays, weld overlay cladding, and refractory materials for high-temperature corrosion and e…

June 6, 2026 Read article →
Line Pipe

What Is ERW Pipe? Manufacturing Process, Grades, and Applications

ERW pipe uses high-frequency resistance welding to form line pipe. API 5L grades B to X70, NPS 2–24. ZC Steel Pipe supplies ERW to Africa and Middle E…

June 3, 2026 Read article →
OCTG

What Are the Grades of OCTG Pipe: N80, L80, P110, Q125 and Beyond

Complete guide to API 5CT OCTG grades: H40, J55, K55, N80, L80, P110, Q125. Mechanical properties, service classification, and selection logic.

June 3, 2026 Read article →
Connections

VAM Top vs Tenaris Blue vs API BTC: Gas-Tight Connection Comparison

Compare VAM Top, Tenaris Blue, and API BTC connections on gas-tight sealing, ISO 13679 ratings, and total installed cost for HPHT and sour wells.

June 3, 2026 Read article →
Flanges & Fittings

Reducer Coupling and Reducing Coupling: Pipe Fitting Selection Guide

Reducer coupling and reducing coupling for pipe systems — types, ASME B16.9 and B16.11 standards, concentric vs eccentric, material grades. ZC Steel P…

June 3, 2026 Read article →
OCTG

OCTG Manufacturing Process: How API 5CT Casing and Tubing Are Made

How API 5CT casing and tubing are made: seamless vs ERW routes, Q+T heat treatment, NDT requirements, and threading. Grade-by-grade manufacturing guid…

June 3, 2026 Read article →
Line Pipe

LSAW Steel Pipe: JCOE Process, API 5L Specifications and Supplier Guide

LSAW steel pipe: JCOE process step by step, API 5L X52–X80 PSL2 specs, OD 406–1524 mm, weld inspection, and procurement guide for pipeline projects.

June 3, 2026 Read article →
Line Pipe

Hydrogen-Ready Pipelines: Line Pipe Selection for H2 Blending

Select hydrogen-ready line pipe for H2 blending: X65M, X70M, ASME B31.12, HIC resistance, embrittlement control, and procurement guidance.

June 3, 2026 Read article →
Coatings

Field Joint Coating Systems: Heat Shrink Sleeves, Liquid Epoxy, and Infill

Heat shrink sleeves, liquid epoxy, and infill field joint coating systems: selection criteria, standards, and inspection for 3LPE, FBE, CWC pipelines.

June 3, 2026 Read article →
Line Pipe

Coiled Line Pipe: Specifications, Sizes, and Offshore Applications

Coiled line pipe specs, OD range, API 5L grades, coiling strain limits, and offshore applications including deepwater flowlines and reeled installatio…

June 3, 2026 Read article →
Flanges & Fittings

ASTM A234 WPB Pipe Fittings: Grades, Specifications and Supplier Guide

ASTM A234 carbon and alloy steel pipe fitting grades — WPB to WP91 chemistry, mechanical properties, temperature limits, and procurement guide. ZC fit…

June 3, 2026 Read article →
General

Alloy Steel Pipe Grades: Chrome-Moly OCTG and Boiler Tube Guide

Chrome-moly alloy pipe grades — OCTG (13Cr, T95, C110) and boiler tube (T11, T22, T91) — grade selection for oil, gas, and power plant applications.

June 3, 2026 Read article →
OCTG

Vacuum Insulated Tubing: Specifications and Thermal Well Applications

Vacuum insulated tubing (VIT) for SAGD, CSS, and geothermal wells — construction, thermal performance, API 5CT grade selection, and procurement guidan…

June 2, 2026 Read article →
OCTG

P110 Casing Failure Analysis — Troubleshooting Failures in HPHT Wells

P110 failure modes in HPHT wells: H2S contamination, over-yield material, collapse, connection gas leaks, thermal fatigue. MTR checks and prevention.

June 2, 2026 Read article →
Line Pipe

Line Pipe vs Pipeline vs Pipe — Key Differences Explained

Line pipe, pipeline, and pipe are not the same thing. This guide explains the technical, regulatory, and commercial differences that matter to EPC eng…

June 2, 2026 Read article →
Connections

BTC in Deviated and Horizontal Wells — Thread Seal Behavior and Limits

BTC thread seal in deviated and horizontal wells: galling risk, bending loads, DLS thresholds, field running procedures, and when to upgrade to premiu…

June 2, 2026 Read article →
Boiler Tube

Boiler Tube Failure: 8 Common Causes and Prevention Guide

The 8 most common boiler tube failure mechanisms — overheating, erosion, corrosion fatigue, hydrogen damage — with diagnosis and prevention for each.

June 2, 2026 Read article →
Boiler Tube

ASTM A333 Grade 6 Low-Temperature Carbon Steel Pipe: Specifications and Applications

ASTM A333 Grade 6 seamless and welded pipe: chemistry, impact test requirements at -45°C, sizes, and procurement guidance for cryogenic and LNG servic…

June 2, 2026 Read article →
Connections

OCTG Connections TCO Guide: Premium vs API Thread Total Cost of Ownership

Total cost of ownership analysis for OCTG connections — compare API BTC vs premium threads across material, running, and NPT costs for well design.

June 1, 2026 Read article →
Line Pipe

Line Pipe vs OCTG: Technical and Regulatory Differences

API 5L line pipe and API 5CT OCTG are not interchangeable — compare standards, chemistry, tolerances, and why field substitution is prohibited.

June 1, 2026 Read article →
Coatings

Cathodic Protection and Pipeline Coatings: Designing a Combined System

Design a combined cathodic protection and coating system for buried pipelines — CP current density, coating selection, holiday testing, and NACE SP016…

June 1, 2026 Read article →
OCTG

API 5CT Tubing Sizes and Weights: Complete Selection Guide

Complete API 5CT production tubing sizes, weights, and connection types from 1.05" to 4.5" OD — NU, EU, and integral joint data for all well condition…

June 1, 2026 Read article →
Stainless

ASTM A312 Stainless Steel Pipe: Grade Selection and Specifications

ASTM A312 stainless steel pipe: grade selection for TP304L, TP316L, TP321, TP347. Chemistry, mechanical properties, and welding requirements.

May 31, 2026 Read article →
Line Pipe

ASTM A106 vs A53 vs API 5L Grade B: Carbon Steel Pipe Selection Guide

ASTM A106 vs A53 vs API 5L Grade B: compare chemistry, mechanical properties, and service scope to select the right carbon steel pipe specification.

May 31, 2026 Read article →
Line Pipe

What Is Line Pipe? API 5L Definition, Grades, and Applications

Line pipe definition, API 5L grades, PSL1 vs PSL2, manufacturing types (ERW, LSAW, seamless), and how line pipe differs from OCTG and structural pipe.

May 26, 2026 Read article →
Connections

BTC Casing Running Procedure: Stabbing, Makeup, and Verification

Step-by-step BTC casing running procedure: pre-run inspection, stabbing, triangle stamp makeup, large-OD handling, and post-makeup logging for field e…

May 26, 2026 Read article →
OCTG

Q125 vs P110 Casing — HPHT Deep Well Selection Guide

Q125 vs P110 casing: yield, chemistry, hardness variation, connections, cost. Which grade for your HPHT sweet well? Full comparison. Request a quote.

May 25, 2026 Read article →
OCTG

Mill Test Certificate MTC — EN 10204 Types, Verification & Procurement

EN 10204 MTC types explained: 2.1, 2.2, 3.1, 3.2. When to specify each for OCTG and line pipe. What to verify before accepting pipe. Procurement guide…

May 25, 2026 Read article →
Stainless

Duplex 2205 and Super Duplex 2507 Stainless Steel Pipe — Selection Guide

Duplex 2205 and super duplex 2507 stainless steel pipe — PREN, mechanical properties, corrosion limits, NACE compliance and procurement guide.

May 25, 2026 Read article →
General

DIN 2391 Cold-Drawn Precision Steel Tubes — Specifications and Tolerances

DIN 2391 precision cold-drawn steel tubes — tolerances, material grades St35 to St52, delivery conditions BK BKW GBK and hydraulic applications guide.

May 25, 2026 Read article →
General

ASTM A572 Structural Steel Plate — Grade 50, 60 and 65 Specifications Guide

ASTM A572 Grade 50 structural steel plate — chemistry, yield strength, weldability, comparison with A36 and A992, and offshore structural applications…

May 25, 2026 Read article →
General

ASTM A519 Seamless Mechanical Tubing — Grades, Tolerances and Selection Guide

ASTM A519 seamless mechanical tubing — carbon and alloy grades 1020 to 4140, OD/wall tolerances, heat treatment conditions and application selection g…

May 25, 2026 Read article →
General

ASTM A516 Pressure Vessel Steel Plate — Grades 60, 65 and 70 Specifications

ASTM A516 Grade 60, 65 and 70 pressure vessel steel plate — chemistry, impact toughness, PWHT and procurement guide for pressure vessels and heat exch…

May 25, 2026 Read article →
Stainless

ASTM A312 TP304L and TP316L Stainless Steel Pipe — Specifications Guide

ASTM A312 TP304L and TP316L stainless steel pipe — chemistry, mechanical properties, heat treatment and corrosion service selection guide.

May 25, 2026 Read article →
Boiler Tube

ASTM A213 Alloy Steel Tubes: T11, T22, T91 and T92 for High-Temperature Service

ASTM A213 T11, T22, T91 and T92 alloy steel boiler tubes — chemistry, high-temperature creep strength, heat treatment and mill cert requirements.

May 25, 2026 Read article →
Boiler Tube

ASTM A192 and A210 Carbon Steel Boiler Tubes — Specifications and Applications

ASTM A192 and A210 seamless carbon steel boiler tubes — chemistry, mechanical properties, heat treatment and power boiler applications guide.

May 25, 2026 Read article →
Line Pipe

ASME B36.10M Pipe Schedule Guide — Wall Thickness, Weight & Selection

ASME B36.10M pipe schedules explained: Sch 40, 80, STD, XS, XXS. Wall thickness, weight tables, how to select schedule for design pressure. Full guide…

May 25, 2026 Read article →
Flanges & Fittings

ASME B16.9 Buttweld Fittings: Elbows, Tees and Reducers — Specifications Guide

ASME B16.9 buttweld fittings — elbows, tees, reducers and caps. NPS ½–48, schedule matching, material grades A234 WPB to WP91. Quote from ZC Steel Pip…

May 25, 2026 Read article →
Flanges & Fittings

ASME B16.5 Pipe Flanges: Pressure Classes, Facing Types and Material Groups

ASME B16.5 pipe flanges — classes 150–2500, weld neck, slip-on and blind types, facing styles and P-T ratings for carbon steel and alloy grades.

May 25, 2026 Read article →
Line Pipe

API 5L X80 PSL2 in Sour Gas Pipelines — HIC Requirements & Selection

Can X80 PSL2 be used in sour gas service? HIC testing requirements, SR15C, chemistry controls, X80 vs X65 vs X70 for sour pipelines. Full guide.

May 25, 2026 Read article →
OCTG

Casing Pipe — Complete Guide to Grades, Sizes, and Selection

Complete guide to API 5CT casing pipe: grades H40–Q125, sizes 4½–20 inch, sour service selection, string design, and procurement checklist.

May 19, 2026 Read article →
OCTG

What Is Oil Tubing — Production Tubing Guide for Oil and Gas Wells

Oil tubing explained: what production tubing does, API 5CT grades, OD sizes, EUE connections, sour service requirements, and selection guide.

May 17, 2026 Read article →
OCTG

What Is OCTG Pipe — Complete Guide to Oil Country Tubular Goods

OCTG pipe explained: casing, tubing, drill pipe grades, API 5CT standards, connections, and selection guide for oil and gas wells. Complete technical …

May 17, 2026 Read article →
OCTG

N80 vs L80 Casing — API 5CT Grade Comparison and Selection Guide

N80 vs L80 casing: yield strength, heat treatment, sour service limits, hardness, cost and selection guide per API 5CT. When to use each grade.

May 17, 2026 Read article →
Line Pipe

HAZ Softening in X65 and X70 LSAW Pipe — Causes, Limits and Field Control

HAZ softening in X65 and X70 LSAW pipe: causes, magnitude, acceptance limits, heat input control, and how to specify pipe with HAZ softening resistanc…

May 17, 2026 Read article →
Line Pipe

API 5L X70 vs X65 — Weldability, Cost and Selection for Pipeline Projects

API 5L X70 vs X65 line pipe: yield strength, weldability, carbon equivalent, cost difference, and when to upgrade from X65 to X70. Pipeline selection …

May 17, 2026 Read article →
OCTG

API 5CT Pup Joints — Specifications, Sizes and Selection Guide

API 5CT pup joints: standard lengths, OD range, grades, tolerances, and when to use pup joints for depth control in casing and tubing strings.

May 17, 2026 Read article →
OCTG

API 5CT J55, K55 and H40 Casing — Grades, Specs and Applications

API 5CT J55, K55 and H40 casing grades: yield strength, differences, dimensions, connections and applications. Low-strength OCTG grades explained.

May 17, 2026 Read article →
OCTG

API 5CT Casing and Tubing Couplings — Specifications and Selection Guide

API 5CT casing and tubing couplings: OD dimensions, grades, STC LTC BTC coupling specs, sour service requirements, and procurement guide. ZC Steel Pip…

May 17, 2026 Read article →
13Cr / CRA

13Cr vs Super 13Cr vs Inhibited Carbon Steel — CO2 Corrosion Selection Guide

13Cr vs Super 13Cr vs inhibited carbon steel for CO2 corrosion: temperature limits, H2S compatibility, cost and selection guide for gas wells.

May 17, 2026 Read article →
Line Pipe

Steel Piling Pipe — ASTM A252 Grades, Specifications & Application Guide

Steel piling pipe ASTM A252: Grade 1, 2 and 3 specs, OD range, wall thickness, yield strength, and application guide for foundation and offshore pilin…

May 16, 2026 Read article →
Connections

Premium Connection Makeup Torque & Running Guide for Casing and Tubing

Premium connection makeup torque, running procedures, common mistakes and field guide for casing and tubing. API 5C1 and manufacturer specs explained.

May 16, 2026 Read article →
Connections

Premium Connection CAL Ratings — ISO 13679 Qualification Guide for OCTG

ISO 13679 CAL ratings for premium casing connections: CAL I–IV explained, gas-tight requirements, HPHT and sour service selection, and procurement gui…

May 16, 2026 Read article →
Coatings

Pipeline Coating Selection for Sour Service and Offshore Applications

Pipeline coating selection for sour service and offshore: FBE, 3LPE, 3LPP, CWC compatibility, cathodic protection, and procurement guide. ZC Steel Pip…

May 16, 2026 Read article →
Line Pipe

LSAW vs Seamless Pipe for Large Diameter Pipelines — Selection Guide

LSAW vs seamless pipe for large diameter pipelines: OD range, wall thickness, grades X65–X80, cost, and selection guide for transmission pipeline proj…

May 16, 2026 Read article →
13Cr / CRA

L80 13Cr Casing & Tubing — Specifications, CO₂ Corrosion Resistance & Supply Guide

L80 13Cr casing and tubing: API 5CT specs, CO₂ corrosion limits, H₂S restrictions, vs Super 13Cr. PSL2 supply with EN 10204 3.2 MTC. Request a quote.

May 16, 2026 Read article →
Coatings

Internal FBE Coating for Line Pipe — Specifications, Applications & Guide

Internal FBE coating for line pipe: specifications, thickness, temperature limits, flow efficiency, application process and procurement guide. ZC Stee…

May 16, 2026 Read article →
Line Pipe

Field Fit-Up Failures — Managing Ovality and Hi-Lo in Large Diameter Girth Welds

Managing ovality and hi-lo misalignment in large diameter pipeline girth welds: causes, acceptance criteria, cold pulling limits, and procurement guid…

May 16, 2026 Read article →
13Cr / CRA

CRA Grade Selection Guide — CO₂ and H₂S Corrosion in Oil & Gas Wells

CRA grade selection for oil & gas wells: L80 13Cr, Super 13Cr, 22Cr duplex, 25Cr, nickel alloys. CO₂ and H₂S partial pressure decision framework.

May 16, 2026 Read article →
Coatings

Concrete Weight Coating for Offshore Pipelines — Specifications & Selection Guide

Concrete weight coating (CWC) for offshore pipelines: density, thickness, design, compatibility with FBE and 3LPP, and procurement guide. ZC Steel Pip…

May 16, 2026 Read article →
Connections

Casing Connection Selection for HPHT, Sour Service and Deviated Wells

Casing connection selection for HPHT, sour service and deviated wells — combined loading, gas-tight requirements, grade compatibility and decision fra…

May 16, 2026 Read article →
Connections

BTC Buttress Thread Casing — Field Guide to Makeup, Failure Modes and Limits

BTC buttress thread casing field guide: triangle stamp makeup, torque values, jump-out failure, gas sealing limits, and when to upgrade to premium con…

May 16, 2026 Read article →
Line Pipe

Beyond PSL2 — API 5L Annex H Metallurgy Requirements for Sour Gas Pipelines

API 5L Annex H requirements for sour gas line pipe: HIC testing, SSC, chemistry limits, hardness, and how to specify beyond standard PSL2 for H₂S serv…

May 16, 2026 Read article →
Connections

API 5CT Tubing Connections — EU and NU External Upset and Non-Upset Guide

API 5CT tubing connections: EU (external upset) vs NU (non-upset) — specifications, tensile ratings, sizes, and selection guide for oil and gas tubing…

May 16, 2026 Read article →
Line Pipe

Welded Steel Pipe: ERW, LSAW and SSAW — Types, Specs & Selection Guide

ERW, LSAW and SSAW welded pipe compared — weld process, size ranges, pressure ratings, API 5L grades, offshore vs onshore. Request a quote from ZC Ste…

May 14, 2026 Read article →
OCTG

OCTG Sour Service Grade Selection — H2S, NACE MR0175 & Hardness Limits

OCTG grade selection for H2S sour service: L80, T95, C110 hardness limits, NACE MR0175 requirements, SSC risk, grade comparison. Quote from ZC Steel P…

May 14, 2026 Read article →
OCTG

Drill Pipe — API 5DP Grades, Sizes, Tool Joints & Selection Guide

Drill pipe grades E75 to S135, OD sizes, tool joint specs, API 5DP inspection classes. Drill pipe supplier for oil & gas. Request a quote from ZC Stee…

May 14, 2026 Read article →
OCTG

Casing Design Basics — Collapse, Burst and Tension Load Analysis

Casing design fundamentals: collapse, burst and tension load calculations, safety factors, grade selection by load case. Engineering guide from ZC Ste…

May 14, 2026 Read article →
13Cr / CRA

Super 13Cr Tubing — Specifications & CO₂ Corrosion Guide

Super 13Cr tubing specs: modified 13Cr, CO₂ corrosion resistance, temperature limits, vs L80 13Cr, sour service limits. Full MTC. Request a quote.

May 13, 2026 Read article →
13Cr / CRA

L80 13Cr vs Super 13Cr — Tubing Selection Guide

L80 13Cr vs Super 13Cr: corrosion envelope, temperature limits, yield strength, H2S tolerance, cost. When to upgrade. Full MTC. Request a quote.

May 13, 2026 Read article →
Line Pipe

Seamless vs Welded Line Pipe — How to Choose

Seamless vs ERW vs LSAW vs SSAW line pipe: pressure ratings, applications, cost, sizes. When each type is correct. Request a quote.

May 12, 2026 Read article →
OCTG

Oil Casing Length Ranges — R1, R2 and R3 Explained

API 5CT casing length ranges: R1, R2, R3 dimensions, when to specify each, average joint length, tubing ranges. Full MTC. Request a quote.

May 12, 2026 Read article →
Line Pipe

API 5L X70 Line Pipe — Specifications & High-Pressure Guide

X70 line pipe: 485 MPa yield, PSL2, LSAW large diameter, X70 vs X65 vs X80, onshore gas transmission. Full MTC. Request a quote.

May 12, 2026 Read article →
Line Pipe

API 5L X65 Line Pipe — Specifications, PSL2 & Applications

X65 line pipe: 450 MPa yield, PSL2 specs, offshore and sour service, X65 vs X70, LSAW and seamless. Full MTC. Request a quote.

May 12, 2026 Read article →
Line Pipe

API 5L X52 Line Pipe — Specifications, PSL1 & PSL2 Guide

X52 line pipe specs: 360 MPa yield, PSL1 vs PSL2, seamless and welded, sour service SR15, sizes and applications. Full MTC. Request a quote.

May 12, 2026 Read article →
Line Pipe

API 5L PSL1 vs PSL2 — Line Pipe Selection Guide

PSL1 vs PSL2 line pipe: testing requirements, chemistry, NDE, impact testing, when to specify each. Full MTC available. Request a quote.

May 12, 2026 Read article →
OCTG

API 5CT T95 Casing Pipe — Specifications, Types & Sour Service Guide

T95 casing specs: 95 ksi yield, Type 1 vs Type 2, NACE MR0175 hardness trap, T95 vs P110 vs L80. PSL-2 sour service. Request a quote.

May 12, 2026 Read article →
Coatings

3LPE vs FBE vs 3LPP — Pipe Coating Selection Guide

3LPE (80°C) vs FBE (95°C) vs 3LPP (110–140°C): layer structure, applications, ISO 21809 spec, coated line pipe supply. Request a quote.

May 12, 2026 Read article →
OCTG

API 5CT P110 Casing Pipe — Specifications, Grades & HPHT Guide

P110 casing specs: 110 ksi yield, HC variants, HPHT applications, P110 vs T95 vs L80, sour service limitations. Full MTC. Request a quote.

May 11, 2026 Read article →
OCTG

API 5CT N80 Casing Pipe — N80-1 vs N80Q Grades & Specifications

N80 casing specs: N80-1 vs N80Q heat treatment, dimensions 4½–20 inch, grade comparison vs L80 and P110. Sour service limitations. Request a quote.

May 11, 2026 Read article →
OCTG

API 5CT L80 Casing Pipe — Grades, Specifications & Sour Service Guide

L80 casing specs: L80-1 vs L80-9Cr vs L80-13Cr, sour service NACE MR0175 compliance, PSL1 vs PSL2, dimensions 4½–13⅜ inch. Request a quote.

May 11, 2026 Read article →
OCTG

API 5CT Casing Pipe — Complete Size & Dimension Guide

Complete API 5CT casing dimension tables: OD, wall thickness, weight, drift diameter for all sizes 4½″ to 20″. Grades N80–Q125. Request a quote.

May 11, 2026 Read article →

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