MSS SP-75 High Strength Butt Weld Fittings
MSS SP-75 Fittings : Specifications | Materials | Dimensions | Weight Chart | Tolerances | FAQ
Premium MSS SP-75 High Strength Butt Weld Fittings – Heavy-Duty Elbows, Tees, Reducers & Caps – Certified for Strength, Safety & Performance – Sizes NPS 2” – 60” – Delivered Worldwide to Thailand, Russia, Oman, South Korea & Chile.
Best Export Prices: sales@midlandforgefittings.com
Midland Forge and Fittings is a trusted manufacturer and supplier of MSS SP-75 High Strength Butt Weld Fittings, built on a foundation of technical precision and reliability. Every fitting we produce undergoes metallurgical testing, dimensional verification, and performance evaluation before dispatch. With advanced forming techniques and automated inspection systems.
Unlike conventional suppliers, we work as a technical partner to EPC contractors and plant operators worldwide. Our expertise lies in delivering customized solutions—whether it’s heavy-wall MSS SP-75 fittings for offshore and power generation or other specialized components for petrochemical and energy projects. With flexible production cells and quick turnaround, we ensure consistent quality with on-time delivery.
MSS SP-75 High Strength Butt Weld Fittings are engineered for demanding high-pressure and high-temperature applications, typically found in oil & gas transmission, petrochemical, and power generation systems. These fittings are manufactured from high-strength low alloy steels and designed to handle severe service conditions such as extreme pressure fluctuations, sour service, and corrosive media. The standard covers seamless and welded elbows, tees, reducers, and caps in sizes ranging from **NPS 2” to 60”
Sustainability and innovation remain at the core of our operations. Midland Forge and Fittings uses recyclable feedstock, energy-efficient furnaces, and advanced quality systems without compromising performance. Our engineering team collaborates closely with clients to align fittings with exact project specifications, guaranteeing durability and compliance for critical industries such as oil & gas, refining, power plants, and marine engineering.
MSS SP-75
MSS SP-75 High Strength Butt Weld Fittings
MSS SP75
High Strength Butt Weld Fittings - Materials, Grades & Standards
| Material Category | Grades / Standards | Specifications / Codes | Typical Applications |
|---|---|---|---|
| Carbon Steel | ASTM A234 WPB / WPC | MSS SP-75, ASME B16.9 | General high-pressure piping, refineries, petrochemical plants |
| Alloy Steel | ASTM A234 WP11, WP22, WP5, WP9 | MSS SP-75, ASME B31.3 | High-temperature service in power plants & process industries |
| High Strength Low Alloy Steel | ASTM A860 WPHY 42 / 46 / 52 / 60 / 65 / 70 | MSS SP-75, API 5L, ASME B31.8 | Pipeline systems, oil & gas transmission, offshore drilling |
| Low Temperature Carbon Steel | ASTM A420 WPL6 / WPL9 | MSS SP-75, ASME B31.4 | Cryogenic service, LNG, low-temperature pipelines |
| Duplex & Super Duplex Stainless Steel | UNS S31803 / S32205 / S32750 | MSS SP-75, NACE MR0175, ISO 15156 | Marine, offshore, subsea pipelines, corrosive service |
MSS SP-75 High Strength Elbows (45° & 90° Long Radius) – Dimensions
| NPS (Inches) | Outside Diameter (OD, mm) | Center-to-End (C, mm) | Wall Thickness (t, mm) | Length (L, mm) | Radius (R, mm) |
|---|---|---|---|---|---|
| 2 | 60.3 | 76 | As per Schedule | 152 | 152 |
| 4 | 114.3 | 152 | As per Schedule | 229 | 229 |
| 6 | 168.3 | 229 | As per Schedule | 305 | 305 |
| 8 | 219.1 | 305 | As per Schedule | 381 | 381 |
| 10 | 273.0 | 381 | As per Schedule | 457 | 457 |
| 12 | 323.9 | 457 | As per Schedule | 533 | 533 |
| 14 | 355.6 | 533 | As per Schedule | 610 | 610 |
| 16 | 406.4 | 610 | As per Schedule | 686 | 686 |
| 18 | 457.2 | 686 | As per Schedule | 762 | 762 |
| 20 | 508.0 | 762 | As per Schedule | 838 | 838 |
| 24 | 610.0 | 914 | As per Schedule | 1016 | 1016 |
MSS SP-75 High Strength Tees (Equal) – Dimensions
| NPS (Inches) | Outside Diameter (OD, mm) | Center-to-End (C, mm) | Wall Thickness (t, mm) | Length (L, mm) |
|---|---|---|---|---|
| 2 | 60.3 | 76 | As per Schedule | 152 |
| 4 | 114.3 | 152 | As per Schedule | 229 |
| 6 | 168.3 | 229 | As per Schedule | 305 |
| 8 | 219.1 | 305 | As per Schedule | 381 |
| 10 | 273.0 | 381 | As per Schedule | 457 |
| 12 | 323.9 | 457 | As per Schedule | 533 |
| 14 | 355.6 | 533 | As per Schedule | 610 |
| 16 | 406.4 | 610 | As per Schedule | 686 |
| 18 | 457.2 | 686 | As per Schedule | 762 |
| 20 | 508.0 | 762 | As per Schedule | 838 |
| 24 | 610.0 | 914 | As per Schedule | 1016 |
MSS SP-75 High Strength Reducers (Concentric) – Dimensions
| NPS (Large × Small, Inches) | Outside Diameter (OD, mm) | Wall Thickness (t, mm) | Length (L, mm) |
|---|---|---|---|
| 6 × 4 | 168.3 × 114.3 | As per Schedule | 229 |
| 8 × 6 | 219.1 × 168.3 | As per Schedule | 305 |
| 10 × 8 | 273.0 × 219.1 | As per Schedule | 381 |
| 12 × 10 | 323.9 × 273.0 | As per Schedule | 457 |
| 14 × 12 | 355.6 × 323.9 | As per Schedule | 533 |
| 16 × 14 | 406.4 × 355.6 | As per Schedule | 610 |
| 18 × 16 | 457.2 × 406.4 | As per Schedule | 686 |
| 20 × 18 | 508.0 × 457.2 | As per Schedule | 762 |
| 24 × 20 | 610.0 × 508.0 | As per Schedule | 914 |
MSS SP-75 High Strength Caps – Dimensions
| NPS (Inches) | Outside Diameter (OD, mm) | Wall Thickness (t, mm) | Length (L, mm) |
|---|---|---|---|
| 2 | 60.3 | As per Schedule | 76 |
| 4 | 114.3 | As per Schedule | 152 |
| 6 | 168.3 | As per Schedule | 229 |
| 8 | 219.1 | As per Schedule | 305 |
| 10 | 273.0 | As per Schedule | 381 |
| 12 | 323.9 | As per Schedule | 457 |
| 14 | 355.6 | As per Schedule | 533 |
| 16 | 406.4 | As per Schedule | 610 |
| 18 | 457.2 | As per Schedule | 686 |
| 20 | 508.0 | As per Schedule | 762 |
| 24 | 610.0 | As per Schedule | 914 |
MSS SP-75 High Strength Fittings - Weight Chart
| Fitting Type | Grade | Nominal Pipe Size (NPS) | Wall Thickness (Schedule) | Weight per Fitting (Kg) |
|---|---|---|---|---|
| Elbow (45°) | WPHY 42 | 1/2″ – 12″ | SCH 40 | 0.35 – 120.0 |
| Elbow (90°) | WPHY 42 | 1/2″ – 12″ | SCH 40 | 0.45 – 130.0 |
| Tee (Equal) | WPHY 42 | 1/2″ – 12″ | SCH 40 | 0.75 – 150.0 |
| Tee (Reducing) | WPHY 42 | 1/2″ – 12″ | SCH 40 | 1.0 – 160.0 |
| Reducer (Concentric) | WPHY 42 | 1/2″ x 3/8″ – 12″ x 10″ | SCH 40 | 0.5 – 170.0 |
| Reducer (Eccentric) | WPHY 42 | 1/2″ x 3/8″ – 12″ x 10″ | SCH 40 | 0.6 – 180.0 |
| Cap | WPHY 42 | 1/2″ – 12″ | SCH 40 | 0.3 – 110.0 |
| Elbow (45°) | WPHY 52 | 1/2″ – 12″ | SCH 40 | 0.4 – 125.0 |
| Elbow (90°) | WPHY 52 | 1/2″ – 12″ | SCH 40 | 0.5 – 135.0 |
| Tee (Equal) | WPHY 52 | 1/2″ – 12″ | SCH 40 | 0.8 – 155.0 |
| Tee (Reducing) | WPHY 52 | 1/2″ – 12″ | SCH 40 | 1.1 – 165.0 |
| Reducer (Concentric) | WPHY 52 | 1/2″ x 3/8″ – 12″ x 10″ | SCH 40 | 0.6 – 175.0 |
| Reducer (Eccentric) | WPHY 52 | 1/2″ x 3/8″ – 12″ x 10″ | SCH 40 | 0.7 – 185.0 |
| Cap | WPHY 52 | 1/2″ – 12″ | SCH 40 | 0.35 – 115.0 |
| Elbow (45°) | WPHY 60 | 1/2″ – 12″ | SCH 40 | 0.45 – 130.0 |
| Elbow (90°) | WPHY 60 | 1/2″ – 12″ | SCH 40 | 0.55 – 140.0 |
| Tee (Equal) | WPHY 60 | 1/2″ – 12″ | SCH 40 | 0.85 – 160.0 |
| Tee (Reducing) | WPHY 60 | 1/2″ – 12″ | SCH 40 | 1.2 – 170.0 |
| Reducer (Concentric) | WPHY 60 | 1/2″ x 3/8″ – 12″ x 10″ | SCH 40 | 0.65 – 180.0 |
| Reducer (Eccentric) | WPHY 60 | 1/2″ x 3/8″ – 12″ x 10″ | SCH 40 | 0.75 – 190.0 |
| Cap | WPHY 60 | 1/2″ – 12″ | SCH 40 | 0.4 – 120.0 |
High Strength Butt Weld Fittings - Tolerances as per MSS SP- 75
| Fitting Type | Dimension / Feature |
Tolerance | Notes |
|---|---|---|---|
| Butt Weld Elbows (45° & 90°) | Outside Diameter (OD) | ±1.6 mm (for ≤ 12″)±2.4 mm (for > 12″) | OD measured at ends |
| Wall Thickness (t) | +12.5% / -0% | Minimum wall thickness must not be less than specified | |
| Center-to-End (C–E) Length | ±1.5% of nominal length | Applies to LR & SR elbows | |
| Bend Radius (LR elbows) | ±3% of nominal bend radius | Applies only to long radius elbows | |
| Tees (Equal & Reducing) | Outside Diameter (OD) | ±1.6 mm (for ≤ 12″)±2.4 mm (for > 12″) | OD at run & branch |
| Wall Thickness (t) | +12.5% / -0% | Minimum thickness control | |
| Center-to-End (C–E) Length | ±1.5% of nominal length | Applies to run & branch | |
| Reducers (Concentric & Eccentric) | Outside Diameter (OD) | ±1.6 mm (for ≤ 12″)±2.4 mm (for > 12″) | OD at larger and smaller ends |
| Wall Thickness (t) | +12.5% / -0% | Minimum thickness must be maintained | |
| Length (L) | ±2% of nominal length | Applies to both concentric & eccentric reducers | |
| Caps / End Closures | Outside Diameter (OD) | ±1.6 mm (for ≤ 12″)±2.4 mm (for > 12″) | OD at sealing end |
| Wall Thickness (t) | +12.5% / -0% | Ensures pressure integrity | |
| General Fabrication Tolerances | Out-of-roundness / Ovality | ≤ 1.5% of nominal OD | Applies to all fittings |
| Angular Deviation (for elbows) | ±1° | Applies to both LR & SR elbows | |
| Surface Finish | As per MSS SP-75: Smooth, free from cracks, seams, or burrs | Internal and external surfaces |
What is the significance of the wall thickness tolerance (+12.5% / -0%) in MSS SP-75 fittings?
MSS SP-75 specifies that the wall thickness of high-strength butt weld fittings may exceed the nominal value by up to 12.5%, but cannot be less than the nominal thickness.
-
Technical Reasoning:
Wall thickness is a critical parameter for pressure-containing components. The minimum wall thickness ensures that the fitting can withstand the specified design pressure without failure. Allowing for an upper tolerance of +12.5% provides flexibility during manufacturing, especially when forming processes such as hot or cold bending can slightly increase wall thickness. -
Engineering Implications:
- Safety: Ensures that no portion of the fitting has a wall thickness below the minimum, preventing weak spots that could lead to localized stress failures or bursting under high-pressure service.
- Fabrication Consideration: Over-thickness may affect the welding preparation, requiring deeper bevels or longer welding passes, which can increase fabrication time and cost.
- Weight and Cost: Excess material adds weight, which can influence transportation and support structures, as well as material cost.
- Practical Insight: Maintaining this tolerance is critical for high-pressure and high-temperature piping systems, where even minor deviations can compromise long-term performance and reliability.
How does MSS SP-75 address out-of-roundness or ovality in fittings?
- MSS SP-75 allows a maximum out-of-roundness of ≤1.5% of the nominal OD for all fittings.
-
Technical Significance:
- Ovality affects the fit-up with mating pipes or flanges. Excessive ovality can lead to gaps, misalignment, or leaks.
- It also affects welding quality because non-uniform surfaces may create incomplete fusion or uneven weld penetration.
-
Inspection Methods:
- Use calipers or specialized OD gauges at multiple points around the circumference.
- For large diameters, coordinate measuring machines (CMM) can ensure precise measurement.
- Maintaining proper roundness ensures both mechanical integrity and sealing performance.
How does MSS SP-75 address out-of-roundness or ovality in fittings?
- MSS SP-75 allows a maximum out-of-roundness of ≤1.5% of the nominal OD for all fittings.
-
Technical Significance:
- Ovality affects the fit-up with mating pipes or flanges. Excessive ovality can lead to gaps, misalignment, or leaks.
- It also affects welding quality because non-uniform surfaces may create incomplete fusion or uneven weld penetration.
-
Inspection Methods:
- Use calipers or specialized OD gauges at multiple points around the circumference.
- For large diameters, coordinate measuring machines (CMM) can ensure precise measurement.
- Maintaining proper roundness ensures both mechanical integrity and sealing performance.
MSS SP-75 High Strength Butt Weld Fittings – Delivered Worldwide
United Arab Emirates (UAE), Saudi Arabia, Oman, Qatar, Kuwait, Bahrain, Iraq, Jordan, Lebanon, Yemen, Iran, Israel, Germany, United Kingdom (UK), Italy, France, Spain, Netherlands, Myanmar, Singapore, Malaysia, Indonesia, Vietnam, South Korea, Philippines, Thailand, Bangladesh, Sri Lanka, Papua New Guinea, United States (USA), Canada, Brazil, Chile, Argentina, Colombia, Russia, Ukraine, Kazakhstan, Poland, Egypt, Algeria, Morocco, Tunisia, Libya, Nigeria, Ghana, Ivory Coast, Senegal, Cameroon, Gabon, Democratic Republic of Congo, Kenya, Tanzania, Uganda, Ethiopia, Rwanda, Zambia, South Africa, Mozambique, Namibia, Botswana