Carbon Steel High Pressure Fittings Supplier

Solitaire Overseas supplies carbon steel high pressure fittings spanning both small bore forged types in ASTM A105, Class 6000 and 9000, and large bore butt weld types in ASTM A234 Grade WPB with Schedule 160 and XXS wall thickness. These heavy wall fittings are built for the most demanding pressure duty across oil and gas, power generation and high pressure utility piping, where standard Class 3000 or Schedule 40 components would not meet the design margin. Every fitting ships with full mill test certification, and hydrostatic or radiographic testing can be arranged on request.

Not sure which pressure class or schedule your system needs?

Contact our piping fittings team for a recommendation, or explore our Carbon Steel Forged Fittings and Carbon Steel Buttweld Fittings ranges directly.

Technical Data

Specifications Chemical Composition Mechanical Properties Pressure / Schedule Reference Approximate International Equivalents

Carbon Steel High Pressure Fittings Specifications

Parameter	Specification
Standard (small bore)	ASTM A105, ASME B16.11, Class 6000/9000
Standard (large bore)	ASTM A234 WPB, ASME B16.9, SCH 160/XXS
Size Range	NPS 1/8" to 48" depending on construction
Pressure Class / Schedule	Class 6000, 9000 / SCH 160, XXS
Construction	Forged (small bore) or seamless/welded pipe (large bore)
Heat Treatment	Normalizing available on request
Testing	Hydrostatic test, radiography, PMI on request
Certification	Mill Test Certificate EN 10204 3.1, 3.2 on request

Chemical Composition (%)

Grade	C max	Mn	P max	S max	Si
A105	0.35	0.60 – 1.05	0.035	0.040	0.10 – 0.35
WPB (A234)	0.30	0.29 – 1.06	0.05	0.058	0.10 min

Mechanical Properties

Grade	Tensile Strength (MPa)	Yield Strength min (MPa)	Elongation min (%)
A105	485 min	250	22
WPB	415 – 655	240	22

Pressure / Schedule Reference

Construction	Rating	Notes
Forged, Class 6000	Socket weld / threaded	6000 psi non-shock, ambient
Forged, Class 9000	Socket weld	9000 psi non-shock, ambient
Butt weld, SCH 160	Butt weld	High pressure, size and temperature dependent per ASME B31.3
Butt weld, XXS	Butt weld	Maximum wall thickness within nominal size, highest pressure margin

Approximate International Equivalents (confirm chemistry against your project code before substitution)

ASTM	EN	JIS
A105	P245GH / P250GH (1.0460), EN 10222-2	G3201 SF440A / SF490A

Types of Carbon Steel High Pressure Fittings

Class 6000 and 9000 socket weld fittings - elbows, tees, couplings, unions
Class 6000 threaded fittings - elbows, tees, couplings
SCH 160 and XXS butt weld fittings - elbows, tees, reducers, caps for large bore high pressure lines

Applications of Carbon Steel High Pressure Fittings

High pressure gas transmission
Boiler feed lines
Hydraulic systems
Well head piping
Steam generation and turbine bypass lines
Chemical injection and metering skids

High Pressure Fitting Selection Matrix

Use this table to match your service requirement to the right high pressure fitting range.

Service Requirement	Recommended Fitting
Small bore (NPS 4" and below), welded joint, up to 9000 psi	Class 9000 Socket Weld Fittings
Small bore, threaded joint, up to 6000 psi	Class 6000 Threaded Fittings
Large bore (NPS 2" and above), continuous pipeline	SCH 160 / XXS Butt Weld Fittings
Sub-zero high pressure service	Carbon Steel Low Temperature Pipe Fittings
Pipeline matched to API 5L X-grade pipe	Carbon Steel High Yield Pipe Fittings

Frequently Asked Questions

Q: What is the highest pressure class available in carbon steel fittings?

A: Forged fittings go up to Class 9000 for socket weld connections; for butt weld fittings, XXS wall thickness offers the highest pressure capacity within a given nominal size.

Q: Do high pressure fittings need special testing?

A: Hydrostatic testing, radiography and PMI can all be specified for high pressure duty; confirm your project's testing requirement when placing an order.

Q: What is the difference between Class 9000 and SCH XXS for high pressure service?

A: Class 9000 is a forged fitting pressure rating used for small bore (NPS 4 inch and below) socket weld connections, while SCH XXS is a wall thickness designation used for large bore butt weld fittings; both represent the top end of pressure capacity within their respective size ranges but are not directly comparable ratings.

Q: Do high pressure fittings require hydrostatic testing by default?

A: Hydrostatic testing is not mandatory under ASTM A105 or A234 by default, but it can be specified as a supplementary requirement and is common practice for critical high pressure systems.

Q: Can high pressure fittings be supplied in low temperature grade?

A: Yes, dual certification combining high pressure class with ASTM A420 WPL6 low temperature toughness can be arranged; specify your minimum design metal temperature when ordering.

Q: What is the lead time for high pressure fittings?

A: Lead time depends on size, class and testing requirements; share your specification sheet with our sales team for a project specific delivery schedule.