Process Pipe and Fittings

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The workhorse of process piping — used across utility, process and structural applications on virtually every oil and gas and industrial project. 

 Pipe

• ASTM A106 Gr.B and C
• API 5L Gr.B
• ASTM A53 Gr.B

Fittings

• ASTM A234 WPB / WPC

Flanges & Forged Fittings

• ASTM A105
• ASTM A350 LF2

• General process and utility pipework on onshore and offshore facilities
• Steam, water and hydrocarbon service pipework
• Injection and disposal well pipework
• Plant interconnecting pipework on processing facilities and LNG plants

For applications requiring improved low-temperature toughness beyond the capability of standard carbon steel grades. 

Pipe

• ASTM A333 Gr.3 / Gr.6

Fittings

• ASTM A420 WPL6 / WPL3

Flanges & Forged Fittings

• ASTM A350 LF2 / LF3

• Cryogenic and low-temperature service pipework
• LNG facility process piping
• Cold climate offshore and onshore installations
• Subsea tie-in pipework requiring low-temperature performance

For high-pressure transmission and flow line applications requiring elevated yield strength. 

 Pipe

• API 5L X52 / X56 / X65 / X70 / X80

Fittings

• ASTM A860 / MSS SP75 WPHY52–80

Flanges & Forged Fittings

• ASTM A694 F52–F80

• Gas and liquid transmission pipelines
• Subsea flowlines and risers
• High-pressure injection and production pipework
• Offshore and onshore pipeline construction

For high-temperature process service where carbon steel grades are insufficient — refineries, downstream processing plants and high-temperature utility systems. 

Pipe

• ASTM A335 P1 / P5 / P9 / P11 / P22 / P91

Fittings

• ASTM A234 WP1 / WP5 / WP9 / WP11 / WP22 / WP91

Flanges & Forged Fittings

• ASTM A182 F1 / F5 / F9 / F11 / F22 / F91

• Refinery and petrochemical plant process piping
• High-temperature steam pipework
• Boiler and heat exchanger interconnecting pipework
• Hydrogen service piping at elevated temperature
• Downstream and LNG facility high-temperature process systems

For corrosion-resistant process service across a broad range of chemical and hydrocarbon processing applications. 

Pipe

• ASTM A312 / A358 — 304 / 316 / 321 / 347 / S31254

Fittings

• ASTM A403 WP304 / WP316 / WP321 / WP347 / S31254

Flanges & Forged Fittings

• ASTM A182 F304 / F316 / F321 / F347 / F44

• Offshore and onshore process piping in corrosive service
• Chemical injection and inhibitor pipework
• Utility and instrument air systems
• Water injection and produced water handling systems
• LNG and cryogenic service pipework

For demanding applications where both corrosion resistance and high strength are required — subsea systems, seawater handling and corrosive process environments. 

Pipe

• ASTM A790 / A928 — S31803 / S32750 / S32760

Fittings

• ASTM A815 — S31803 / S32750 / S32760

Flanges & Forged Fittings

• ASTM A182 F51 / F53 / F55

• Subsea manifold and flowline pipework
• Topsides process piping in sour or corrosive service
• Seawater lift and injection systems
• Produced water and chemical injection pipework
• Offshore desalination and water treatment systems
• NORSOK-compliant subsea and topsides systems

For the most extreme corrosive and high-temperature service environments where stainless and duplex grades are insufficient. 

Pipe, Fittings & Flanges

• Alloy 625
• Alloy 825
• Alloy 800

• Highly corrosive process environments in downstream and chemical plants
• High-temperature furnace and heat exchanger pipework
• Sour gas service applications requiring superior corrosion resistance
• Subsea and topsides systems handling aggressive produced fluids

For marine and offshore seawater service applications requiring excellent biofouling resistance and corrosion performance. 

Pipe, Fittings & Flanges

• EEMUA 234 UNS 7060X

• Offshore platform seawater cooling and fire water systems
• Marine vessel hull and seawater pipework
• Desalination plant pipework
• Offshore and coastal infrastructure seawater handling system

For applications where standard catalogue fittings and flanges cannot meet the project's dimensional, pressure rating or material requirements, STS sources bespoke and custom-manufactured fittings and forgings from our international supply network.

Bespoke items are manufactured to client-supplied drawings, specifications and purchase order quality requirements — with full third-party inspection, material traceability and documentation managed by STS from enquiry through to delivery.

• Non-standard bore and wall thickness fittings outside standard dimensional ranges
• Special facing, bore or end preparation flanges
• High-pressure fittings and flanges beyond standard pressure class ratings
• Large diameter fittings and flanges not available from standard stock
• Orifice flanges and spectacle blinds to project-specific dimensions
• Weld neck flanges with special hub geometries
• Custom reducing fittings and lateral tees to project drawings
• Subsea and high-integrity pressure-containing components
• Hammer union and threaded end fittings for special applications
• Bespoke forgings for valve bodies, nozzles and pressure vessel components

• Carbon and low alloy steel
• High yield grades
• CrMo alloy steel
• Stainless steel
• Duplex and super duplex
• Nickel alloy
• Copper nickel

• Full material traceability and heat certification
• Third-party inspection and dimensional verification
• Material test reports and certificates of conformance
• Documentation packages to project quality system requirements

Short lead time bespoke supply is a recurring requirement on active projects — particularly where standard items like carbon steel pipe have been rejected, dimensions have changed late in design, or a single critical component, such as high yield line pipe, is holding up fabrication. STS's international supply network and supplier relationships mean we can source and expedite bespoke items, including process piping, faster than conventional procurement routes.