Carbon Steel MSS SP-75 WPHY Pipe Fittings Manufacturer & Exporter

Solitaire Overseas supplies high test wrought butt welding fittings manufactured to MSS SP-75 in ASTM A860 Grade WPHY material. Built from fully killed carbon or low alloy steel and heat treated in every case, these fittings deliver minimum yield strengths from 42,000 to 70,000 psi, well above standard ASTM A234 WPB or WPC fittings, making them the standard choice for high pressure oil and gas transmission pipelines, compressor stations and metering facilities. MSS SP-75 sets its own dimensional tables for NPS 16 through NPS 60, while smaller WPHY fittings down to NPS 1/2 follow ASME B16.9 dimensions.

Types of Carbon Steel MSS SP-75 Fittings

Long Radius (LR) Elbow
3R Elbow
Straight Tee
Reducing Tee
Concentric / Eccentric Reducer
Cap
Pipe Bend

WPHY fittings are typically supplied to connect with API 5L line pipe or ASTM A694 forged pipe flanges.

Need fittings for moderate pressure service rather than high yield pipeline duty? See our ASTM A234 WPB / WPC / WPA Pipe Fittings, or our ASME B16.9 Carbon Steel Buttweld Fittings hub.

Technical Data

Specifications Chemical Composition Mechanical Properties Approximate Equivalents

Carbon Steel MSS SP-75 Fittings Specifications

Parameter	Specification
Standard	MSS SP-75 (chemistry, tensile properties, dimensions NPS 16–60); ASME B16.9 governs dimensions for NPS 14 and smaller
Material Specification	ASTM A860 Grade WPHY 42 / 46 / 52 / 56 / 60 / 65 / 70
Size Range	NPS 1/2" to 60" (NPS 16–60 per MSS SP-75 tables; smaller sizes per ASME B16.9)
Wall Thickness	Sch 10, Sch 40, Sch 80 and heavier, per project specification
End Connection	Butt weld
Manufacturing	Seamless or electric fusion welded, fully killed carbon/low alloy steel
Heat Treatment	Mandatory — annealing, normalizing, normalizing & tempering, or quenching & tempering
Hardness	22 HRC (235 HBW) max per ASTM A860
Certification	Mill Test Certificate EN 10204 3.1, 3.2 on request

Chemical Composition (MSS SP-75, % — applies to all WPHY grades)

Element	Maximum %
Carbon (C)	0.30
Manganese (Mn)	1.60
Phosphorus (P)	0.035
Sulfur (S)	0.035
Copper (Cu)	0.50
Nickel (Ni)	0.50
Silicon (Si)	0.50
Chromium (Cr)	0.25
Molybdenum (Mo)	0.13
Vanadium (V)	0.13
Columbium/Niobium (Cb)	0.10
Titanium (Ti)	0.05

The sum of Copper, Nickel, Chromium and Molybdenum shall not exceed 1.00%. All grades must also conform to a carbon equivalent limit agreed between purchaser and manufacturer.

Mechanical Properties (MSS SP-75 Table 2, all thicknesses)

Grade	Yield Strength min	Tensile Strength min	Elongation min
WPHY-42	290 MPa (42,000 psi)	414 MPa (60,000 psi)	25%
WPHY-46	317 MPa (46,000 psi)	434 MPa (63,000 psi)	25%
WPHY-52	359 MPa (52,000 psi)	455 MPa (66,000 psi)	25%
WPHY-56	386 MPa (56,000 psi)	490 MPa (71,000 psi)	20%
WPHY-60	414 MPa (60,000 psi)	517 MPa (75,000 psi)	20%
WPHY-65	448 MPa (65,000 psi)	531 MPa (77,000 psi)	20%
WPHY-70	483 MPa (70,000 psi)	565 MPa (82,000 psi)	18%

Approximate Equivalents to API 5L Line Pipe Grades

MSS SP-75 / ASTM A860 Grade	API 5L Grade	Approx. EN Equivalent
WPHY-42	X42	L290
WPHY-52	X52	L360
WPHY-60	X60	L415
WPHY-65	X65	L450
WPHY-70	X70	L485

Applications of Carbon Steel MSS SP-75 Fittings

Long distance oil and gas transmission pipelines
Compressor and pumping stations
Metering and regulating stations
Cross country pipeline tie ins and mainline connections
High pressure gas distribution networks

MSS SP-75 vs ASME B16.9 / ASTM A234 - Which to Choose

Both standards produce carbon steel buttweld fittings, but they target different pressure classes and service duty. Use this table to pick the right one.

Criteria	MSS SP-75 (WPHY)	ASME B16.9 (ASTM A234 WPB/WPC)
Yield Strength Range	290 – 483 MPa (42 – 70 ksi)	240 – 275 MPa (35 – 40 ksi)
Typical Service	High pressure oil & gas transmission pipelines	General process and pressure piping
Size Range	NPS 16" to 60" (own tables); NPS 14" & under per B16.9	NPS 1/2" to 48"
Heat Treatment	Mandatory on every fitting	Optional, grade and process dependent
Matches Pipe Grade	API 5L X42 – X70	ASTM A106/A53 Gr B/C, API 5L Gr B
Learn More	This page	ASME B16.9 Pipe Fittings

Frequently Asked Questions

What does WPHY mean?

WPHY stands for Wrought Pipe or Wrought Plate, High Yield. The number that follows, from 42 to 70, indicates the minimum yield strength of the fitting in ksi.

What size range does MSS SP-75 cover?

MSS SP-75 provides its own dimensional tables for NPS 16 through NPS 60. For NPS 14 and smaller, WPHY fittings are dimensioned per ASME B16.9 instead.

Is heat treatment mandatory for WPHY fittings?

Yes. All MSS SP-75 fittings must be supplied in the heat treated condition, using annealing (stress relieving), normalizing, normalizing and tempering, or quenching and tempering.

Which WPHY grade should I select?

Grade selection is typically matched to the connecting API 5L line pipe grade, for example WPHY-60 for X60 pipe. Grades 60, 65 and 70 are common in high pressure transmission service, while grades 42 through 56 are often specified alongside, or in place of, ASTM A234 WPB or WPC in medium to high pressure lines.

What testing is available for WPHY fittings?

Hydrostatic testing, tensile testing, PMI or spectrographic analysis, Charpy impact testing, radiography, magnetic particle inspection, ultrasonic testing and liquid penetrant examination are all available per project specification.

Can WPHY fittings be used in sour service?

Standard WPHY chemistry is not automatically NACE compliant. Sulfur control, hardness limits and supplementary testing to NACE MR0175 / ISO 15156 should be specified separately for sour gas or H2S service.

Get a quote for carbon steel MSS SP-75 WPHY buttweld fittings from Solitaire Overseas, or visit our Carbon Steel Pipe Fittings hub to compare forged, buttweld, high yield and material grade options side by side.