Dimensions & Pressure Ratings
MSS SP-44 Standard Flanges: Dimensions | Specifications | Material Grade | Standards | About MSS SP-44 | All Product Types
MSS SP-44 flanges are high-strength forged steel flanges developed specifically for pipeline systems in the oil, gas, petrochemical, and offshore sectors. This standard was established by the Manufacturers Standardization Society (MSS) to define the requirements for Steel Pipeline Flanges in sizes NPS 1½″ to 24″ and pressure classes 150, 300, 600, and 900, making them highly suitable for demanding high-pressure and high-temperature systems.
Unlike general-purpose flange standards, MSS SP-44 strictly governs the dimensions, facing types (Raised Face / RTJ), tolerances, bolting patterns, and thicknesses for Welding Neck and Blind Flanges. These flanges are typically Series A and are often used as equivalents to ASME B16.47 Series A flanges, especially for API pipelines and transmission lines.
At Nutech, we manufacture and export MSS SP-44 flanges in full compliance with global specifications. All flanges undergo precision machining, dimensional inspection, and hydro testing, and are supplied with EN 10204 3.1 / 3.2 certification, including NACE MR0175, PED, and IBR approval where required. These flanges are available with face finishes like stock finish, spiral serrated, or smooth finish, ensuring optimal gasket compatibility.
We also offer custom drilling patterns, coating options (black paint, anti-rust varnish, hot-dip galvanizing), and special packaging for export shipments. Our SP-44 flange solutions are engineered for performance and reliability in critical service environments, with 100% traceability and compliance to project documentation.
For complete technical details, including dimensions, pressure rating classes, weight charts, sizes, tolerances, and material specifications of our MSS SP-44 Standard Flanges, please download the full Catalog PDF below.
Specification | Details |
---|---|
Standard | MSS SP-44 (Steel Pipeline Flanges) |
Flange Types | Weld Neck (WN), Blind (BL) |
Size Range | 1½″ to 24″ NPS (DN40 to DN600) |
Pressure Ratings | Class 150, 300, 400, 600, 900 |
Face Types | Raised Face (RF), Ring Type Joint (RTJ) |
Design Criteria | Series A dimensions, ANSI B16.5 bolt patterns, pipeline-focused tolerance requirements |
Manufacturing Process | Forged, Machined, Heat Treated, Stress Relieved (as required) |
Testing & Inspection | Hydrostatic Testing, PMI, UT/MPI, Dimensional & Visual Inspection |
Marking | Standard per MSS SP-25 – Size, Rating, Heat No., Material, Manufacturer |
Documentation | EN 10204 3.1 / 3.2, NACE MR0175, ISO 9001, PED 2014/68/EU |
Application Industries | Oil & Gas, Petrochemical, Power Generation, Water Treatment, Food & Beverage, Fire Protection Systems, Pulp & Paper, Shipbuilding, HVAC, Offshore |
Origin | Made in India (by Nutech Overseas) |
Export Network | USA, Europe, and Middle East |
Material Category | MSS SP-44 Flange Grades |
---|---|
Stainless Steel MSS SP-44 Flange | ASTM A182 F304 / F304L / F304H, F316 / F316L / F316Ti, F310, F309S, F317 / F317L, F321 / F321H, F347 / F347H, F904L, ASTM A351 CF3 / CF3M / CF8 / CF8M / CF8C, DIN 1.4301, 1.4306, 1.4307, 1.4311, 1.4401, 1.4404, 1.4408, 1.4409, 1.4541, 1.4571, 1.4550, 1.4435, 1.4539 |
Duplex Steel MSS SP-44 Flange | ASTM A182 F51 / F52 / F53 / F54 / F55 / F57 / F59 / F60 / F61, UNS S31803 / S32205 |
Super Duplex Steel MSS SP-44 Flange | ASTM A182 F53 / F55 / F57 / F59 / F60 / F61, UNS S32750 / S32760 |
Carbon Steel MSS SP-44 Flange | ASTM A105 / A105N, ASTM A350 LF2, ASTM A694 F52 / F56 / F60 / F65 / F70 / F80, ASTM A216 WCB, DIN 1.0460 / 1.0402 / 1.0619, Die Steel, Mild Steel |
Alloy Steel MSS SP-44 Flange | ASTM A182 F5 / F9 / F11 / F12 / F22 / F91, AISI 4130 / 4140 |
Nickel Alloy MSS SP-44 Flange | Nickel 200 / 201, ASTM B564 |
Monel MSS SP-44 Flange | Monel 400 (UNS N04400), Monel K500 (UNS N05500), ASTM B564 |
Inconel MSS SP-44 Flange | Inconel 600 / 601 / 625 / 690 / 718 / 783 / X750, ASTM B564 |
Incoloy MSS SP-44 Flange | Incoloy 800 / 800H / 800HT (UNS N08800), Incoloy 825 (UNS N08825), Incoloy 925, ASTM B564 |
Hastelloy MSS SP-44 Flange | Hastelloy C276 (UNS N10276), C22 (UNS N06022), C4, C2000, B2, B3, X, ASTM B564 |
Alloy 20 MSS SP-44 Flange | Alloy 20 / 20Cb-3, Carpenter® 20, ASTM B462 |
254 SMO MSS SP-44 Flange | SMO 254 / 6Mo, UNS S31254, DIN 1.4547, ASTM A182 |
Copper Nickel MSS SP-44 Flange | Copper Nickel 90/10 (C70600), 70/30 (C71500), UNS C71640, ASTM B61 / B62 / B151 / B152 |
Copper MSS SP-44 Flange | TP1, TP2, T1, T2, C10100–C12300, C14200–C17200, C21000–C71520, including C10930, C11000, C11400, C12000, C12200, C26000, C28000, C33000, C44300, C70600, etc. |
Brass MSS SP-44 Flange | Grades 3602, 2604, H59, H62, etc. |
Aluminium MSS SP-44 Flange | Aluminium Grades 5052, 6061, 6063, 2017, 7075, etc. |
Titanium MSS SP-44 Flange | ASTM B381 Gr.1 / Gr.2 / Gr.4 / Gr.5 / Gr.7, UNS R50250 / R50400 / R50550 / R50700 / R52400 / R53400 / R56320 / R56400 |
Other Special Grades | Al6XN, Tin Bronze, Aluminium Bronze, Lead Bronze, Nimonic 75 / 80A / 90 |
MSS SP-44 is a technical standard published by the Manufacturers Standardization Society (MSS) that defines the requirements for steel pipeline flanges, specifically Weld Neck and Blind flanges used in high-pressure transmission systems such as oil & gas pipelines.
Key differences between MSS SP-44 and other flange standards like ASME B16.5 include:
MSS SP-44 is tailored for pipeline applications, while ASME B16.5 serves general industrial piping systems.
Covers NPS 1½″ to 24″ and Class 150, 300, 400, 600, 900 pressure ratings. For larger diameters, it aligns with ASME B16.47 Series A.
MSS SP-44 specifies more robust wall thicknesses, tighter dimensional tolerances, and heavier-duty designs than B16.5 for enhanced durability.
Includes Raised Face (RF) and Ring Type Joint (RTJ) options, with bolt-hole patterns matching pipeline standards.
This standard ensures that the flanges meet stringent pipeline integrity requirements, particularly in high-pressure and high-temperature operating conditions.
MSS SP-44 flanges are typically supplied with Raised Face (RF) or Ring Type Joint (RTJ) facing, and each face type requires compatible gaskets to ensure a leak-proof seal under pressure.
Here’s how gasket selection works for MSS SP-44:
Choosing the right gasket ensures long-term performance, pressure containment, and safety in demanding oil & gas or petrochemical pipelines.
MSS SP-44 specifies strict dimensional tolerances to ensure interchangeability, consistent performance, and integrity in high-pressure pipeline systems. These tolerances are especially critical during site installation and welding.
Key tolerance criteria include:
These tight tolerances reduce the risk of leaks, misalignments, and installation errors — especially important for pipeline systems operating under high stress and thermal cycling.
Yes, MSS SP-44 flanges are partially compatible with ASME B16.5 flanges under specific conditions, particularly in terms of bolt-hole patterns and pressure ratings. However, there are important technical differences that must be considered:
Compatibility Aspects:
Differences to Watch:
Flanges can often be mated across these standards, but a detailed dimensional review is necessary for high-integrity applications. Always confirm with engineering drawings and relevant specs before mixing standards.
Material selection for MSS SP-44 flanges depends on the pressure rating, temperature range, and chemical compatibility of the media in the pipeline. The standard allows flanges to be manufactured from carbon steel, low-temperature carbon steel, stainless steel, and even alloy grades where required.
Common Materials & Their Service Suitability:
Additional Considerations:
Material selection directly affects flange performance, weldability, and service life — making it a crucial engineering decision.
Nutech is a trusted global manufacturer and exporter of MSS SP-44 standard flanges, supplying critical pipeline components to a wide range of international markets. Our export network spans across oil & gas hubs, infrastructure projects, and industrial zones worldwide.
We regularly export MSS SP-44 Weld Neck and Blind Flanges to:
With certifications, fast lead times, and compliance with international standards, Nutech ensures secure and consistent deliveries for large-scale and urgent project requirements.