MSS SP-44 Flange

MSS SP-44 flange

MSS SP-44 refers to the steel pipeline flanges specifications covers pressure-temperature ratings, materials, dimensions, tolerances and testings.

Material Grades from F36, F42, F46, F48, F50, F52, F56, F60, F65, F70, F80, which names from yield strength by 36 ksi (F36) to 80 ksi (F80).

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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.

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.

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

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.

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

Pressure Temperature Ratings

Flanges understand the standard has follwing pressure ratings: Class 150, 300, 400, 600 or 900.

Sizes

NPS and DN as follows:

NPS 12 14 16 18 20 22 24 26 28 30 32 34 36
DN 300 350 400 450 500 550 600 650 700 750 800 850 900
NPS 38 40 42 44 46 48 50 52 54 56 58 60
DN 950 1000 1050 1100 1150 1200 1250 1300 1350 1400 1450 1500

Materials of MSS SP-44

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.

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.

Chemical Composition

Table 1

Elemen​​​​​t Limits (%)
Min. Max.
C - 0.3
Mn 0.6 1.6
P - 0.025
S - 0.025
Si 0.15 0.35
Cu - 0.4
Ni - 0.4
Cr - 0.3
Mo - 0.12
V - 0.11
Nb - 0.05
B - 0.001
Cu+Ni+Cr+Mo - 1

Tensile Requirements of MSS SP-44

Tensile Requirements

SI (Metric) and U.S. Customary

Grade Yield Point
(Min.)
Tensile Strength
(Min.)
Elongation 50mm 
Mpa ksi Mpa ksi (2 in.) (Min. %)
F36 248 36 414 60 20
F42 290 42 414 60 20
F46 317 46 414 60 20
F48 331 48 427 62 20
F50 345 50 441 64 20
F52 359 52 455 66 20
F56 386 56 469 68 20
F60 414 60 517 75 20
F65 448 65 531 77 18
F70 483 70 552 80 18
F80 550 80 620 90 16

Impact Test

Impact testing is not required for Grade F42 and lower. 

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.

Hardness

Hardness shall be HBW 235 as maximum.

Bolting

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. 

Heat Treatment

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-44 Flange Design Spec

Tolerances

MSS SP-44 flange toleance

Drilling template

The flange drilling template is determined as follows:

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

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.

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.

Flange Ring design

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

Hub Design

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.

NPS 60 and Smaller

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.

Marking

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.

Facing

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.

Raised Face

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).

Ring Joint

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

Flange Testing

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.

Application of flanges

Applications

A flange is a method of connecting pipes, valves, pumps, and other equipment to form a piping system. It also provides easy access for cleaning, inspection, or modification.

When a piping joint requires to be dismantled, flanges are being used. These are primarily used on equipment, valves, and specialty items. Breakout flanges are provided at predetermined intervals in certain pipelines where maintenance is a regular occurrence. The flanges, gaskets, and bolting make up a flanged joint, which is made up of three separate but interconnected components. To achieve a leak-proof joint, special controls are required in the selection and application of all of these elements.

Here are the details of Flanges about their advantages and their applications.

Advantages of Flanges

Pipes, valves, pumps, and other parts are connected with flanges to form a piping system. Generally, flanges are welded or screwed together. The use of flanges makes pipe system maintenance and repair a breeze. Instead of taking the entire pipe for inspection, a small section of the pipe can be carefully investigated to use a flange to locate the fault.

The following are the five most important benefits of The following are the five most important benefits of flanges:

A flange is a method of connecting pipes, valves, pumps, and other equipment to form a piping system. It also provides easy access for cleaning, inspection, or modification. Flanges are usually welded or screwed.

In many applications, engineers need to find a way to close off a chamber or cylinder in a very secure fashion, usually because the substance inside must differ from the substance outside in composition or pressure.

They do this by fastening two pieces of metal or other material together with a circle of bolts on a lip. This “lip” is a flange.

Plumbing

You can connect two sections of metal piping by soldering or welding them together, but pipes connected in this way are very susceptible to bursting at high pressures. A way of connecting two sections of pipe more securely is by having flanged ends that you can connect with bolts. This way, even if gases or liquids build up to high pressures inside the pipe, it will often hold with no problem.

Mechanics

In order to connect two sections of a large, enclosed area, it is often best to used flanges and bolts. An example of this is the connection between the engine and the transmission in an automobile. In this case, both the engine and the transmission contain a number of moving parts that can easily get damaged if they get dust or other small objects inside of them. By connecting the outer casings of the engine and transmission in this way, engineers protect the inner workings of both.

Electronics

Flanges have a specific purpose in cameras and other electronic devices. Though flanges in such items do not usually have to sustain high pressures, they do have to hold tight so they can keep out harmful particles. These flanges are usually found connecting two different materials, such as the glass of a lens and the rest of the body of the camera.

Flanged connection

There are many ways to connect flanges, including threading, welding or bolting. The threaded flange is best for low pressure or smaller pipelines because it can maintain its seal. When your pipeline is larger or high pressure, then the welded flange is preferable. A boiler room is one place where welded blind flanges might be used, due to the high pressure involved.

Flanged joints: flanges, bolts and nuts and gaskets

A flange is a external rib at the end of pipes, valves and other flow devices to assemble them.

Dimensions of the flanges are up to specific Standards : DIN, ANSI, AS, BS, JIS

Flanged connection

A flanged connection requires two flanges (the “main” and the “companion”), a set of bolts and nuts (whose number depends on the flange diameter and class) and two sealing gaskets. Flanged connections have to be executed and supervised by trained personnel, as the quality of the joint has a critical impact on the performance of the piping system / pipeline (the standard TSE – TS EN 1591 Part 1-4, “Flanges and their joints”, defines a number of requirements for the execution of proper flanged connections). Whereas all elements of the joint are critical, experience shows most leaks are originated by the improper installation of the sealing elements, i.e. the gaskets.

The typical pipe to flange connections are welded or threaded. Welded flanges are used for pipelines and piping systems with high pressures and temperatures, and with diameters above 2 inches.

Threaded connections are instead used for installations of smaller diameter and not subject to severe mechanical forces such as expansion, vibration, contraction, oscillation (forces that would crack the threaded joint). In all these critical cases, butt weld connections are recommended.


Materials

Pipe flanges are manufactured in all the different materials like stainless steel, cast iron, aluminium, brass, bronze, plastic etc. but the most used material is forged carbon steel and have machined surfaces.

Flanges are welded to pipe and equipment nozzle. Accordingly, it is manufactured from the following materials;

The list of materials used in manufacturing is covered in ASME B16.5 & B16.47.

Commonly used Forged material grads are

Frequently used astm grades

Material Fittings Flanges Valves Bolts & Nuts
Carbon Steel A234 Gr WPA A105 A216 Gr WCB A193 Gr B7
A194 Gr 2H
A234 Gr WPB A105 A216 Gr WCB
A234 Gr WPC A105 A216 Gr WCB
Carbon Steel
Alloy
High-Temp
A234 Gr WP1 A182 Gr F1 A217 Gr WC1 A193 Gr B7
A194 Gr 2H
A234 Gr WP11 A182 Gr F11 A217 Gr WC6
A234 Gr WP12 A182 Gr F12 A217 Gr WC6
A234 Gr WP22 A182 Gr F22 A217 Gr WC9
A234 Gr WP5 A182 Gr F5 A217 Gr C5
A234 Gr WP9 A182 Gr F9 A217 Gr C12
Carbon Steel
Alloy Low-Temp
A420 Gr WPL6 A350 Gr LF2 A352 Gr LCB A320 Gr L7
A194 Gr 7
A420 Gr WPL3 A350 Gr LF3 A352 Gr LC3
Austenitic Stainless Steel A403 Gr WP304 A182 Gr F304 A182 Gr F304 A193 Gr B8
A194 Gr 8
A403 Gr WP316 A182 Gr F316 A182 Gr F316
A403 Gr WP321 A182 Gr F321 A182 Gr F321
A403 Gr WP347 A182 Gr F347 A182 Gr F347

ASTM standards define the specific manufacturing process of the material and determine the exact chemical composition of pipes, fittings and flanges, through percentages of the permitted quantities of carbon, magnesium, nickel, etc., and are indicated by "Grade".

The usual materials of flanges include stainless steel, carbon steel, aluminum and plastic. The choice of the material largely depends on the purpose of the flange. For example, stainless steel is more durable and is necessary for heavy use. On the other hand, plastic is more feasible for use in the home because of its reasonable price and easy installation. The materials used for flanges are under the designation of the American Society of Mechanical Engineers.

Flange materials acc. to ASTM

The most common materials for pipe flanges (forged grades) are: ASTM A105 (carbon steel high temperature to match A53/A106/API 5L pipes), A350 Grades LF1/2/3 (carbon steel low temperature to match A333 pipes), A694 Grades F42 to F80 (high yield carbon steel to match API 5L pipe grades), ASTM A182 Grades F5 to F91 (alloy steel flanges to match A335 pipes), A182 Grade F304/316 (stainless steel flanges to match A312 SS pipes), A182 Gr. F44/F51/F53/F55 (duplex and super duplex to match A790/A928 pipes) and various nickel alloy grades (Inconel, Incoloy, Hastelloy, Monel).

The material qualities for these flanges are defined in the ASTM standards.

What are ASTM Grades?

For example, a carbon steel pipe can be identified with Grade A or B, a stainless-steel pipe with Grade TP304 or Grade TP321, a carbon steel fitting with Grade WPB etc.


Standard

Pipe Flange Standards mainly include three systems in the world, ANSI/ASME flange system(American), DIN flange system(European system), JIS flange system, other system made according to this three systems, like GB flange standard, which mainly made according to ANSI/ASME and DIN flange standard, Duwa Piping supplies those flanges with top quality and soonest delivery time.

ASME standards

ASTM standards

AWWA standards

ISO standards

MSS standards

Pipe bend

FAQs

The most frequently asked questions regarding flanges and flange fittings have to do with how flanges fit on specific steel tube and steel pipe ends.

How flanges operate?

Flange process

Flanges have flat or flush surfaces that are vertical to the pipe to which they are attached. The attachment process involves mechanically joining two or more faces using bolts, adhesives, collars, or welds. Due to the attachment requirements, a flange must fit the equipment or pipe that it’s designed. That’s why it’s necessary to check all the possible specifications and dimensions to ascertain that it’s of the right size, type, and material.

What are the three parts of a flanged connection?

Pipe flanges, gaskets, and bolts are the three parts that comprise a flanged connection. Gaskets and bolts are typically made of the same flange materials or a material approved for the pipe components. Each component comes in various materials that suit specific applications and must be matched correctly for proper functioning. The gaskets come in two conventional types: full-face gaskets and ring gaskets. Full-face gaskets have the bolt holes visible and pair up with raised-face gaskets. Ring gaskets tend to be smaller rings minus the bolt holes and pair up with flat-faced flanges. Securing the flange components requires matching the surfaces evenly and plumb, adjusting as needed for a uniform fit. Once all surfaces match, bring the flanges together and secure at least two of the bolts. Refine the alignment, so the remaining bolt holes match and their corresponding bolts are tightly secured.

How do I properly size a flange for pipe use?

Properly sizing a flange for pipe use depends not only on the type of flange but its compatible piping. The pipe must slip into the flange’s inside diameter easily and securely, and the outside diameter should cover wall holes. Once you determine the specific flange type and material you need for the job, you’ll need to take several measurements. The four measurements you’ll need are the inside diameter, outside diameter, bolt hole count, and bolt hole center. You’ll need to align each of these measurements from opposing bolt holes to get the most accurate readings. Take all measurements from edge to edge and try to get as precise as possible to match the correct product. Round up bolt diameter to the next half or whole step since bolts measure half or whole inches. Once you have all four measurements, check them against the manufacturer’s table to find the correct flange. Most manufacturers list these specifications on their websites for easy reference.

Flange Inspection

Before dispatching from manufacture each flange is inspected to ensure quality. During an inspection you have to check the following;

ASME B16.5 and B16.47 standards cover permissible tolerances for inspection.

Flange material standards

Flanges are used to connect pipes or other equipment components in various industries, and they come in a variety of materials and sizes. Flange material standards are developed by standard-setting organizations and describe the properties and characteristics of different materials that can be used to make flanges. Some examples of commonly used flange material standards include:

  1. ASTM A105: This standard covers forged carbon steel piping components, including flanges, that are suitable for use in high-pressure applications.
  2. ASTM A182: This standard covers forged or rolled alloy steel pipe flanges, forged fittings, and valves and parts intended for high-temperature service.
  3. ANSI B16.5: This standard specifies the dimensions, tolerances, and markings for steel pipe flanges and flanged fittings.
  4. DIN 2632-2638: This standard defines the dimensions and tolerances for flanges made from steel, including carbon steel, stainless steel, and other alloys.
  5. ASME B16.47: This standard covers large diameter steel flanges, typically used in high-pressure applications where larger bore sizes are needed.
  6. BS 4504: This British standard covers circular flanges for pipes, valves, and fittings, with nominal sizes ranging from 15 to 600 mm.

The choice of flange material standard will depend on various factors such as the application, the environment, the fluid being transported, and the required performance characteristics. For example, high-pressure applications may require flanges made from materials with high strength and durability, while corrosive environments may require flanges made from materials with good resistance to corrosion.


Delivery

Steel flanges must be packed with seaworthy packing method then delivery to customers, usually the packing way include wooden box, wooden pallet, iron & steel cage, iron & steel pallet etc.

PMI-raw material inspection

Flange raw material PMI
Flange raw material PMI
Flange raw material PMI

Flange Marking

Flange markings are governed by ANSI ASME codes. Flange marking includes;

  • Manufacturer logo
  • ASTM material code
  • Material Grade
  • Service rating (Pressure-temperature Class))
  • Size
  • Thickness (Schedule)
  • Heat No
  • Special marking if any QT (Quenched and tempered) or W (Repair by welding)
Flange Marking

Size inspection

ASME B16.5 and B16.47 standards cover permissible tolerances for inspection.

Flange size inspection
Flange size inspection
Flange size inspection
Flange size inspection
Flange size inspection
Flange size inspection

Packing

Because of the normal wooden boxes or wooden pallets have to do fumigation treatment, we usually use plywood pallet or plywood case or box to pack steel flanges without fumigation treatment.

Flange size inspection
Flange size inspection
Flange size inspection

【H】 Ceramic lined pipe

Ceramic lined pipe is made through self-propagating high-temperature synthesis (SHS) technique.

【H】 Cast basalt lined steel pipe

Cast basalt lined steel pipe is composed by lined with cast basalt pipe, outside steel pipe and cement mortar filling between the two layers.

【H】 Ceramic Tile Lined Pipes

Ceramic tile lined pipes have very uniform coating of specially formulated ceramic material that is affixed to the inner of the pipe.

【H】 Rare earth alloy wear-resistant pipe

The material of the rare earth alloy wear-resistant pipe is ZG40CrMnMoNiSiRe, which is also the grade of rare earth alloy steel.

【H】 Tubes Erosion Shields

Tubes Erosion Shields are used to protect boiler tubing from the highly erosive effects of high temperatures and pressures thereby greatly extending tube life.

【H】 ASTM A213 T91 Alloy Tube

The ASTM A213 T91 seamless tubes are primarily used for boiler, superheater, and heat-exchanger.

Ni-Hard Wearback Pipes Ni-Hard Wearback Pipes
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