MSS SP-44 covers pressure-temperature ratings, materials, dimensions, tolerances, marking, and testing for steel pipeline flanges.

MSS SP-44涵盖了钢制管道法兰的压力温度额定值、材料、尺寸、公差、标记和测试。

MSS SP-44 is the standard for high-strength, cold-worked, carbon steel grade welding for pipelines. It provides guidelines for the design, manufacturing, and testing of flanges used in pipeline systems.

MSS SP-44是管道高强度冷加工碳钢级焊接的标准。它为管道系统中使用的法兰的设计、制造和测试提供了指导方针。

The flanges covered by MSS SP-44 range in size from NPS 12 to NPS 24, and they are equivalent to ASME B16.5 flanges. Additionally, MSS SP-44 also covers flanges larger than NPS 26, which are known as ASME B16.47 Series A flanges.

MSS SP-44涵盖的法兰尺寸范围为NPS 12至NPS 24，与ASME B16.5法兰相当。此外，MSS SP-44还涵盖了大于NPS 26的法兰，即ASME B16.47 A系列法兰。

It is important to note that MSS SP-44 is the only source for NPS 22 flange dimensions.

值得注意的是，MSS SP-44是NPS 22法兰尺寸的唯一来源。

The standard inlcudes all the flange types in forged steel or steel inlcudes Weld Neck Flange, Slip On Flange, Lap Joint Flange and Blind flanges and etc.

该标准涵盖了锻钢或钢制的所有法兰类型，包括焊接颈法兰、滑动法兰、搭接法兰和盲板法兰等。

Dimensional and tolerance requirements for NPS 10 and smaller flanges in this standard refer to ASME B16.5. 

本标准中NPS 10及以下法兰的尺寸和公差要求参见ASME B16.5

Pressure Temperature Ratings压力温度额定值

Flanges understand the standard has follwing pressure ratings: Class 150, 300, 400, 600 or 900.法兰知道该标准具有以下压力等级：150、300、400、600或900级。

Sizes尺寸

NPS and DN as follows:NPS和DN如下：

Materials of MSS SP-44MSS SP-44的材料

All materials used for making MSS SP-44 flanges shall be "killed" steel. It shall be suitable for field welding to other flanges, fittings, or pipe manufactured according to ASTM A105, A53, A106, A350, A381, A516, A537, A694, A707 and API 5L.

用于制造MSS SP-44法兰的所有材料应为“镇静”钢。它应适用于现场焊接至根据ASTM A105、A53、A106、A350、A381、A516、A537、A694、A707和API 5L制造的其他法兰、配件或管道。

It defines maximum carbon content of 0.30%, and CE shall not exceed 0.48%, based on ladle analysis, without prior approval of the purchaser. If the CE exceeds 0.45%, the flange shal be marked with actual CE result. All test methods shall be as specified in ASTM A370.

根据钢包分析，未经买方事先批准，其规定的最大碳含量为0.30%，CE不得超过0.48%。如果CE超过0.45%，法兰上应标记实际CE结果。所有试验方法应符合ASTM A370的规定。

Chemical Composition化学成分

Table 1

Tensile Requirements of MSS SP-44MSS SP-44的拉伸要求

Tensile Requirements拉伸要求

SI (Metric) and U.S. CustomarySI（公制）和美国惯用单位

Impact Test冲击试验

Impact testing is not required for Grade F42 and lower. F42级及以下不需要进行冲击试验。 

From each steel sheet, one set (three specimens) shall be tested at a maximum temperature of -45℃ (-50℉) and show 27J (20ft-lb) minimum average, 20J (15 ft-lb) individual minium.

从每块钢板中，应在-45℃（-50℉）的最高温度下对一组（三个试样）进行测试，并显示最小平均值27J（20ft-lb），单个最小值20J（15ft-lib）。

Hardness硬度

Hardness shall be HBW 235 as maximum.

硬度最大应为HBW 235。

Bolting螺栓连接

Boltings listed in Table 3 shall be used in flanged joints covered by MSS SP-44. Bolting produced from other materials may be used if permitted by the applicable code or governmental regulation. 

MSS SP-44涵盖的法兰接头应使用表3中列出的螺栓。如果适用规范或政府法规允许，可以使用其他材料制成的螺栓。 

Heat Treatment热处理

MSS SP-42 F42 and higher grades shall be normalized, normalized and tempered, quenched and tempered, or precipitation treated and aged. Class 400 and higher classes of Grade F36 flanges shall be anneald, normalized, normalized and tempered, or quenched and tempered as defined in ASTM A961; But the minimum tempering temperature shall be 540℃ (1000℉).

MSS SP-42 F42及更高等级应进行正火、正火和回火、淬火和回火，或沉淀处理和时效。400级及以上F36级法兰应按照ASTM A961的规定进行退火、正火、正火和回火，或淬火和回火；但最低回火温度应为540℃（1000℉）。

MSS SP-44 Flange Design Spec  MSS SP-44法兰设计规范

Tolerances 公差

Drilling template钻孔模板

The flange drilling template is determined as follows:法兰钻孔模板确定如下：

The Class 150 flange drilling template is identical to the Class 125 in ASME B16.5 and ASME B16.1.

150级法兰钻孔模板与ASME B16.5和ASME B16.1中的125级相同。

The drilled template for class 300 flanges smaller than or equal to NPS24 is the same as that for class 250 flanges in ASME B16.5 and ASME B16.1. The drilled templates for class 400, class 600, and class 900 flanges in sizes less than or equal to NPS24 are the same as those for ASME B16.5.

小于或等于NPS24的300级法兰的钻孔模板与ASME B16.5和ASME B16.1中的250级法兰的模板相同。尺寸小于或等于NPS24的400级、600级和900级法兰的钻孔模板与ASME B16.5的钻孔模板相同。

The NPS 26 through NPS 60 Class 150, 300, 400, 600, and 900 flanges are the same as those of series A flanges in ASME standard B16.47.

NPS 26至NPS 60 150、300、400、600和900级法兰与ASME标准B16.47中的A系列法兰相同。

Flange Ring design法兰环设计

For flanges with nominal pipe diameter less than or equal to NPS24, the outer diameter and flange thickness shall meet the requirements of ASME B16.5. For flanges with nominal pipe diameters of NPS26 through NPS60, the outer diameter and flange thickness shall comply with the requirements of ASME B16.47 for series A flanges

对于公称管径小于或等于NPS24的法兰，外径和法兰厚度应符合ASME B16.5的要求。对于公称管径为NPS26至NPS60的法兰，外径和法兰厚度应符合ASME B16.47对A系列法兰的要求

Hub Design枢纽设计

ASME B16.5 and B16.47 weld flange ratings are based on the weld flange neck and have a calculated wall thickness at least equal to the pipe. The pipe has a specified minimum yield strength of 276 MPa (40000 psi) and a maximum bore size.

轮毂设计ASME B16.5和B16.47焊接法兰额定值基于焊接法兰颈部，计算壁厚至少等于管道。该管道的规定最小屈服强度为276 MPa（40000 psi），最大孔径为。

NPS 60 and Smaller   NPS 60及以下

When the mechanical properties (minimum yield strength) of the various parts are equal to or greater than the line to which it is connected, the flange neck may be the same size as specified in the ASME B16.5 or 16.47A series.

当各部件的机械性能（最小屈服强度）等于或大于其连接的管线时，法兰颈的尺寸可以与ASME B16.5或16.47A系列中规定的尺寸相同。

Marking标记

Flanges shall be marked in accordance with the rules specified in MSS Standard Practice SP-25. In addition, the letter PL should be added before the level symbol. The grade symbol on the weld neck flange marks the material grade of the weld flange neck.

法兰应按照MSS标准规程SP-25中规定的规则进行标记。此外，字母PL应添加在电平符号之前。焊接法兰上的等级符号标记了焊接法兰颈部的材料等级。

Facing外装

The accuracy of the pipe flange contact surface should be determined by the visual comparison method using the Ra sample block instead of the stylus plotter and the electronic magnifier.

管道法兰接触面的精度应通过使用Ra样品块而不是触针绘图仪和电子放大器的视觉比较法来确定。

Raised Face 凸面

It provide concentric serrated or helical teeth with an accuracy between 3.2 μm (125 μinch) and 6.3μm (250μinch). The cutting tool used shall have a radius greater than or equal to 1.5mm (0.06 in) and 1.7 to 2.2 grooves per mm (44 to 55 grooves per inch).

它提供同心锯齿或螺旋齿，精度在3.2μm（125μ英寸）至6.3μm（250μ英寸）之间。所用切削刀具的半径应大于或等于1.5mm（0.06英寸），每毫米1.7至2.2个凹槽（每英寸44至55个凹槽）。

Ring Joint环形密封面型

The side surface roughness of gasket groove shall not exceed 1.6μm （63μinch）.

垫片槽的侧面粗糙度不得超过1.6μm（63μin）。

Flange Testing翻边

Hydrostatic test of the flange is not required. However, the hydrostatic pressure test of the flange joint may be carried out at a pressure not exceeding 1.5 times the 38 ° C (100 ° F) rating.

无需对法兰进行静水压试验。但是，翻边的静水压试验可以在不超过38°C（100°F）额定值1.5倍的压力下进行。