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ANSI Flange

Date:2023-06-25View:275Tags:ANSI Flange
ANSI American standard flanges are generally referred to as flanges produced in accordance with American flange standards. ANSI American standard flanges are widely used in foreign-funded enterprises or foreign trade exports. Flange implementation standard ANSI B16.5, ANSI B16.47. ANSI American Standard flange pressure rating is expressed in pounds, class150LB refers to 150 pounds of pressure. The ANSI American standard flange pressure rating Class mark has 6 pressure ratings, namely: Class 150; Class 300; Class 600; Class 900; Class1500; Class 2500.

ANSI American standard flanges are parts that connect pipes to pipes and are connected to pipe ends. Flange connection or flange joint refers to the detachable connection of flange, gasket and bolt as a group of combined sealing structure. Pipe flange refers to the flange used for piping in pipeline installations. The upper refers to the import and export American standard flange of the equipment.


American Applied Standards System (ANSI)

The American National Standard ANSI B16.5 "Steel Pipe Flanges and Flanged Fittings" is a relatively complete, mature and internationally popular and common advanced standard. This standard and other relevant ANSI, API, ASTM, and MSS pressure pipeline application standard systems are formed on the basis of a large number of experimental studies and have experienced decades of practical testing. Therefore, it is a scientific, advanced standard and widely used. accepted by all countries.

Tube: Large outer diameter series (ANSI B36.10 and ANSI B36.19)
Nominal diameter range: (DN6~DN2000)mm
Wall thickness representation method:
1) The wall thickness is represented by the pipe table number "Sch";
2) The pipe wall thickness is represented by the weight of the pipe.
Pipe flange: American flange
Pressure rating: CL 150 300 400 600 900 1500 2500 Psi 7 levels,
Nominal pressure: 150Lb (2.0Mpa), 300Lb (5.0Mpa), 400Lb (6.8Mpa), 600Lb (10.0Mpa), 900Lb (15.0Mpa), 1500Lb (25.0Mpa), 2500Lb (42.0Mpa).


150LB means 300 pounds, CL means pressure class, CL 150(PN2.0), CL300(PN5.0), CL600 (PN11), CL900 (PN15), CL1500 (PN26), CL 2500 (PN42)
Nominal diameter: DN15~600mm
Flange sealing surface: convex surface (RF), concave-convex surface (MF), tongue and groove surface (TG), metal ring connection surface 4 types
Flange type: 6 kinds of flat welding type, socket welding type, butt welding type, threaded connection type, loose sleeve type and flange cover
The abbreviations WN, So, BL, TH, LJ, and SW in the American standard flange mainly indicate the flange neck and simplified or takeover

The welded structure form:

WN (welding neck) is [neck butt welding flange]
so (slipon) is [slip-on flange with neck]
BL (blind) is [flange cover], also called "blind plate"
TH (thread) is [threaded neck flange]
LJ (lap joint) is [loose flange] this kind of now does not exist in the new standard in 2009, it is revised
Change to [LF/SE butt welding ring loose flange]
SW (socket welding) is [socket welding flange]

Example 1: ANSI B16.5 150lbs 3"M Flange
ANSIB16.5 is the American flange system; 150LB is the pressure rating of 150 pounds; 3" indicates the size of the flange
is 3 inches; the code name of the convex flange is M, and the convex flange needs to be matched with the concave flange, commonly known as "one male and one female", the M surface method
The blue needs to be connected with the FM surface (concave-convex surface MF).

Example 2: CL150, WNRF, STD, A105, ASME B16.5 flange
ASME B16.5 is the executive standard for flanges, which belongs to the American system and is commonly called American Standard. The domestic standard is called the national standard, and the industry
Standards include those of the Ministry of Chemical Industry, those of the Ministry of Machinery, and so on. STD, A105 is the material of the flange, which belongs to carbon steel. WN, is with
The code name of the strong butt welding flange means high neck, and PL flat welding, so strong flat welding, RF is the sealing surface type! It is a raised surface
Yes! CL150 is the pressure of the flange, which is about 2MPA.


ASME is the American Society of Mechanical Engineers
ANSI is the American National Standards Institute
They all have their own standards and standard numbers. The pressure level is in the ANSI standard, but the ASME standard is now
Directly refer to this standard. This phenomenon is very common in various standards in the United States. For example, ASME SA105 is equivalent to ASTM
A105, ASME B16.5 is equivalent to ANSI B16.5 and so on.


The commonly used standards in the American application standard system ANSI are:

ANSIASME B36.10 seamless and welded steel pipes
ANSI/ASME B36.19 stainless steel seamless and welded steel pipes
ANSI/ASME B16.9 Factory Made Steel Butt Weld Pipe Fittings
ANSIASME B16.11 Socket weld and thread forged pipe fittings
ANSIASME B16.28 Steel butt welding small radius elbows and return elbows
ASME/ANSI B16.34 flanged, threaded and welded valves
ASME/ANSI B16.5 Pipe Flanges and Flanged Fittings
ASME/ANSI B16.36 orifice plate flange
ASME/ANSI B16.42 Ductile Iron Flanges and Flanged Fittings
ASME/ANSI B16.47 Large Diameter Steel Flanges
ASME/ANSI B16.20 spiral-wound, wrap-around gaskets for pipe flanges and metal gaskets for ring grooves

ASME/ANSI B16.21 Non-Metallic Flat Gaskets for Pipe Flanges
ASME/ANSI B18.2.1 Square and Hex Head Bolts and Threads
ASME/ANSI B18.2.2 Square and Hex Head Nuts
API std605 large diameter flange, flange cover
API std526 flange connection steel pressure relief valve
Inspection and test of API std598 valves
API std599 flanged and welded metal plug valves.
API std600 flanged and butt welded steel gate valves
API std602 small steel gate valve (compact gate valve)
API std603 150 lb corrosion-resistant flanged valve
APIstd608 metal ball valve with flange connection and butt welding connection
APIstd609 Lug and Wafer Butterfly Valves
API std6D pipeline valve specification

MSS SP-44 neck flat welding flange

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