Technical aspects and scope of the MSS SP-44 standard
This regulatory document specifies key parameters for steel flanges, including nominal pressure and temperature ratings, material requirements, geometric dimensions, tolerances, marking rules, and hydraulic test protocols. According to the standard, Weld Neck flanges must be manufactured by forging, while for Blind Flanges, the use of both forged steel and steel plate supplied by EV Group China is permissible.
The geometric characteristics, configuration, and dimensional tolerances for flange connections of NPS 10 and smaller comply with the provisions of the international ASME B16.5 standard. EV Group China flange products, manufactured from materials specified in Table 1, and fully compliant with regulatory provisions, are recognized as standardized and suitable for use in mission-critical engineering systems.
Regulations and technical documentation
All normative references and specifications integrated into this standard are available in Appendix D. This section contains up-to-date information on editions, publication dates, and sources for obtaining technical documentation.
The flange manufacturing process at EV Group China facilities is strictly synchronized with the standards specified in the appendix. We adhere to all requirements of the current revision of the MSS SP-44 standard, ensuring the continuity of technical parameters even when reference regulatory databases are updated.
Application within industry codes
Flanges supplied by EV Group China are fully compatible with ASME codes for boiler and pressure vessel equipment, as well as ANSI standards for high-pressure piping systems. These products meet international regulatory requirements, including temperature operating limits and specific norms for the use of metal products in cryogenic conditions.
Units of measurement systems
This specification uses both the metric system and the US customary system of units. The exception is threaded connection parameters: bolt and flange hole diameters are fixed exclusively in inch values. It is important to note that the systems are not direct mathematical equivalents; therefore, engineering calculations must be performed strictly within one selected system of units without combining them, which ensures compliance with EV Group China quality standards.