Prefabricated Steel Pipe Spools Supplier & Manufacturer for Oil & Gas EPC Projects 

PETROL STEEL CO., LTD. provides and customizes prefabricated steel pipe spools for Oil & Gas EPC projects, providing project-specific piping packages to engineering contractors, procurement teams, project buyers, construction contractors, importers, and industrial piping contractors. We manufacture pipe spools from carbon steel, stainless steel, duplex and super duplex, alloy steel, and low-temperature steel, according to approved isometric drawings, project specifications, piping classes, and relevant international standards. For standard orders, typical lead time is approximately 5-6 weeks, based upon the scope of the project, material availability, fabrication requirements, inspection, and documentation. The goal is obvious: to provide pipe spools that can be recognized, inspected, transported, and installed with the minimum of uncertainty at the site.

A pipe spool is not just a pipe with fittings welded on it. It is a pipe spool for EPC procurement teams. It is a controlled project element. Material / Size / Thickness / Welding / NDT / Dimensions / Testing / Coating / Identification / Documentation / Packing and Delivery. ASME B31.3 covers process piping, including piping used in petroleum refining, chemical, cryogenic, and related processing facilities, and covers the design, materials, fabrication, assembly, examination, inspection, and testing of these systems. PETROL STEEL therefore structures its Pipe Spool Fabrication around the engineering information contained in the project ISO drawing and applicable piping specification. Cutting may include CNC plasma, flame, or laser cutting and beveled equipment; forming may include cold or hot bending, usually R=3D-5D, or seamless/welded pipe. Welding processes include GTAW, SMAW, GMAW, and SAW. Welders qualify for ASME Section IX / ISO 9606 and WPS/PQR as per project requirements. PWHT or stress relieving, where required. End machining, beveling, flange/fitting preparation, and controlled spool assembly.

Materials, Sizes, and Fabrication Scope 

PETROL STEEL can supply carbon steel pipe spools in ASTM A106 Gr.B, ASTM A105, API 5L Gr.B/X42–X70, and ASTM A333 Gr.6 low-temperature grades; stainless steel in ASTM A312 TP304/304L, TP316/316L, TP321, and TP347; duplex and super duplex grades in ASTM A790 S31803, S32205, and S32750; alloy steel in ASTM A335 P5, P9, P11, P22, and P91; and low-temperature materials in ASTM A333 Gr.1/3/6 and ASTM A350 LF2/LF3. Typical spool sizes are NPS 2″–48″ (DN50–DN1200). NPS 4″–24″ is common for major onshore and offshore process lines, and NPS 30″–48″ is for certain large-diameter pipeline stations and related applications. Wall thicknesses can be in the range of approximately 3.0–60 mm, including SCH 10S through SCH XXS, depending on specified material, piping class, and project requirements.

The normal individual precast spool length is 6 to 12 m, typically limited to about 12.5 m by transportation considerations. Modular fabrication sections may be about 3 to 8 m for containerized or frame-supported transportation. Field fit-up allowances are reserved at spool ends as specified by the project (approximately 50-100 mm). PETROL STEEL also offers external corrosion protection as per the project environment, such as epoxy zinc-rich primer/epoxy intermediate/polyurethane systems for C4/C5 service, heat-resistant silicone coating for high-temperature service, 3LPE/3LPP or FBE for buried or subsea applications, and HDG or TSA for selected offshore applications. Internal cleaning or lining requirements can also be incorporated if specified. 

Quality Control from Material Receipt to Final Release 

One of the most common questions from international Engineering Procurement and Project Buyer teams is not simply “Can you fabricate the spool?” but “How do you prove that the spool that was delivered to our site is the spool that is shown on our ISO drawing and specified in our purchase order?” PETROL STEEL does this by material identification, controlled fabrication, inspection, and documentation. Dimensional inspection shall include overall spool dimensions, flange-to-flange dimensions, angular orientation, bolt hole rotation, bevel preparation, ovality, and straightness as per the applicable project requirements. Welding is controlled by approved WPS/PQR and qualified welders. NDT includes RT, UT, MT, and PT, with PAUT/TOFD available for applicable thick-wall or critical welds. PMI is used for material verification mainly on duplex, super duplex, and alloy steel components.

Inspection can include Factory Acceptance Testing (FAT) and third-party inspection such as SGS, BV, DNV, or TÜV when required in the purchase order or inspection and test plan. Pressure testing shall be by hydrostatic or pneumatic methods in accordance with the applicable project code and approved procedure. Where PWHT is required, quality documentation may include heat-treatment records and hardness verification. A typical documentation package can include EN 10204 3.1/3.2 material documentation, NDT reports, welder qualifications, WPS/PQR, PWHT charts, pressure-test certificates, and Manufacturer’s Data Report (MDR). This documentation-centric approach becomes especially critical for EPC projects in which the procurement, QA/QC, engineering, and construction teams may all be required to review the same spool package before installation at the site.

Standards for Oil & Gas and International EPC Projects 

PETROL STEEL supplies to project specifications based on applicable international standards, including ASME B31.3, ASME B31.4, ASME B31.8, ASME B16.5, ASME B16.47, ASTM/ASME, API 5L, EN 10216, and ISO 3183, in combination with applicable welding, inspection, and corrosion-protection requirements such as ASME Section IX, ISO 15614, AWS D1.1, ASNT SNT-TC-1A, ISO 9712, API 1104, ISO 12944, NACE SP0169, and ISO 21809. Depending on the actual project specification and approved material data sheets, project-specific requirements may include NORSOK M-630/M-650, Shell DEP, BP GS EP, and Saudi Aramco SAES for offshore and international oil & gas projects. NORSOK M-630 has added specific material requirements for piping systems designed according to ASME B31.3, where material control is of particular importance for relevant upstream oil and gas projects.

Here is also the difference between a regular pipe supplier and a Pre-fabricated Steel Pipe Spools project supplier. A spool package must pass a material inspection AND work within the EPC schedule. The fabrication sequence should include consideration of availability of materials, drawing revision control, weld sequence, inspection hold points, testing, coating, identification, packing, transportation, and installation. Shop fabrication is consistently cited in industry experience as a means of shifting welding and quality-control activities away from congested project sites. Research into spool fabrication has also drawn attention to the relationship between material supply, fabrication scheduling, and downstream site installation. 

Applications across the Oil & Gas and Energy Value Chain 

PETROL STEEL Prefabricated Pipe Spools for Oil Gas EPC ASME B31.3 applications are for upstream, midstream, and downstream facilities, including offshore fixed and floating platforms FPSO facilities, onshore gathering systems, wellhead and manifold piping, transmission pipelines, compressor and pump stations, LNG receiving terminals, underground gas storage, and metering stations. Downstream applications are refineries, petrochemical, chemical, and fertilizer plants. The same fabrication capability can be used for selected power generation piping, marine systems, mining slurry lines, seawater desalination facilities, and stainless steel process or hygienic piping where the applicable project specification allows.

A Modular Construction Project’s Modular Pipe Rack prefabrication shop workflow can include pipe spools as well, where dimensions, lifting points, transportation limits, and installation sequence must be considered prior to fabrication. Current industry practice still emphasizes off-site prefabrication, modular construction, schedule control, and reduced field work. For the EPC contractor, the practical value is not in the number of welds done in the workshop but in receiving correctly identified, inspected, and documented piping assemblies that fit the intended installation sequence.

Why International EPC Buyers Work with PETROL STEEL 

PETROL STEEL has over 10 years of export experience in prefabricated pipe spools, with an experienced project team that has 10+ years of technical experience, 20+ years of international trade and marketing experience, 10+ years of quality control experience, and 15+ years of logistics experience. For each project, our teams support technical clarification, commercial communication, quality coordination, documentation, packing, shipment, and after-sales communication. Our typical lead time for conventional orders is 5-6 weeks, with the final schedule confirmed against project scope and approved technical requirements.

We have a very simple quality policy, i.e., each and every PETROL STEEL pipe spool is subject to internal QC inspection and independent third-party inspection before delivery (if required). The aim is to offer EPC procurement teams traceable material, controlled welding, documented inspection, and predictable delivery, not just a low purchase price. For more than 10 years, PETROL STEEL has been supplying prefabricated pipe spool products globally, with a proven track record of zero claim cases on products and services in this field. As a Norsok M-630-capable supplier for Pipe Spool Fabrication, an ASME B31.3 oil & gas pipe spool supplier, or a project-oriented partner for conventional carbon, stainless, duplex, alloy, and low-temperature steel spools, PETROL STEEL can review project ISO drawings, MTO, piping class, and inspection requirements and prepare a technical and commercial quotation. 

Send Your ISO Drawing, MTO, or RFQ → PETROL STEEL Technical Review → Fabrication & QC → Inspection & Documentation → Export Packing → Project Delivery. 

Technical Specification Summary