Flanges

Threaded Flanges are also known as screwed flange, and it is having a thread inside the flange bore which fits on the pipe with matching male thread on the pipe. This type of joint connection is Speedy and simple but not suitable for high presser and temperature applications. Threaded Flanges are mostly used in utility services such as air and water.

A flanged joint is composed of three components; flanges, gaskets, and bolting; which are assembled by pipe fitter. Special controls are required in the selection and application of all these elements to attain a joint, which has acceptable leak tightness.

However, it is not advisable to use a flange connection in underground piping when it supposed to be buried. The flange is also the most common source of leak and fire in a process plant. There are a variety of flanges available to suit the requirements. 

Slip on Flange is essentially a ring that is placed over the pipe end, with the flange face extending from the end of the pipe by enough distance to apply a weld bead on the inside diameter. The OD of slip on flange is also welded on the back side of the flange.

Flangeolet is a combination of olet (mainly weldolet or nipple) and flange. Hub length is longer like long neck weld flange. It is 90 Degree branch connection use for high-pressure piping. It reduces the two weld joints than traditional Olet + Pipe + Flange connection and one weld joint in case of Olet + Flange connection. You can see the image of the flangeolet branch.

Class 600 Flangeolet, Class 900 Flangeolet, Class 1500 Flangeolet, ANSI B16.5 class 150 Flangeolet

Dimensions:  ANSI B16.5, ANSI B16.47 Series A & B, MSS SP44, ASA, API-605, AWWA, Custom Drawings
Size: 1/2″ (15 NB) to 48″ (1200NB)
DIN: DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631, DIN2632, DIN2633, DIN2634, DIN2635, DIN2636,DIN2637, DIN2638, DIN2673
BS: BS4504 , BS4504, BS1560, BS10
Class: 150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS, DIN Standard ND-6,10, 16, 25, 40 Etc.Flange Face Type: Flate Face (FF), Raised Face (RF), Ring Type Joint (RTJ)

 ASME B16.5 Flangeolet Material Specification

Stainless Steel Flangeolet:
ASTM A 182, A 240 F 304, 304L, 304H, 316, 316L, 316Ti, 310, 310S, 321, 321H, 317, 347, 347H, 904L

Duplex & Super Duplex Steel Flangeolet:
ASTM / ASME A/SA 182 F 44, F 45, F51, F 53, F 55, F 60, F 61

Carbon Steel Flangeolet:
ASTM / ASME A/SA 105 ASTM / ASME A 350 , ASTM A 181 LF 2 / A516 Gr.70 A36, A694 F42, F46, F52, F60, F65, F706

Low Temperature Carbon Steel Flangeolet: ASTM A350, LF2, LF3 

Alloy Steel Flangeolet:
ASTM / ASME A/SA 182 & A 387 F1, F5, F9, F11, F12, F22, F91

Copper Alloy Steel Flangeolet :
ASTM SB 61 , SB62 , SB151 , SB152 UNS No. C 70600 (Cu-Ni 90/10), C 71500 (Cu-Ni 70/30), UNS No. C 10100, 10200, 10300, 10800, 12000, 12200

Nickel Alloy Flangeolet:
ASTM SB564, SB160, SB472, SB162 Nickel 200 (UNS No. N02200), Nickel 201 (UNS No. N02201), Monel 400 (UNS No. N04400), Monel 500 (UNS No. N05500), Inconel 800 (UNS No. N08800), Inconel 825 (UNS No. N08825), Inconel 600 (UNS No. N06600), Inconel 625 (UNS No. N06625), Inconel 601 (UNS No. N06601), Hastelloy C 276 (UNS No. N10276), Alloy 20 (UNS No. N08020)

The pipe flanges are the second most used joining method after welding. They are used when joints need dismantling. It provides flexibility for maintenance. Flange connects the pipe with various equipment and valves. Breakup flanges are added in the pipeline system if regular maintenance is required during plant operation.
A flanged joint is composed of three components; flanges, gaskets, and bolting; which are assembled by pipe fitter. Special controls are required in the selection and application of all these elements to attain a joint, which has acceptable leak tightness.

Standard ANSI: ANSI B16.5, ANSI B16.47, MSS SP44, ANSI B16.36, ANSI B16.48 ,JIS,DIN,BS4504,SABS1123,EN1092-1, UNI,AS2129,GOST-12820

DIN: DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631, DIN2632, DIN2633, DIN2634, DIN2635, DIN2636, DIN2637, DIN2638, DIN2673

B.S: BS4504 , BS4504, BS1560, BS10

Pressure Class 150, Class 300, Class 400, Class 600, Class 900, Class 500, Class 2500 | PN 6, PN 10, PN 16, PN 25, PN40, PN 64 etc.

Size: 15 NB to 750 NB, 1/2-78 inch (DN15-DN2000)

Connection Type: Raised Face, Flat Face, Ring Type Joint, Lap-Joint Face, Large Male-Female, Small Male-Female, Large Tongue & Groove, Small Tongue & Groove.

Carbon Steel: A-350 LF2 LF3, A105

TESTING FACILITIES:
Chemical Analysis
Mechanical Test
Metallography Test
Hydrostatic
Corrosion Test
Ultrasonic Test
Radiography
Miscellaneous Test

CERTIFICATES & APPROVALS:
EIL
IBR

Additional Information
Delivery Time: Ready stock
Packaging Details: Wooden Box

The flanges are the second most used joining method after welding. They are used when joints need dismantling. It provides flexibility for maintenance. Flange connects the pipe with various equipment and valves. Breakup flanges are added in the pipeline system if regular maintenance is required during plant operation. A flanged joint is composed of three components; flanges, gaskets, and bolting; which are assembled by pipe fitter. Special controls are required in the selection and application of all these elements to attain a joint, which has acceptable leak tightness.

A flange can be classified in several alternate ways as follows:
Based on Types of Connection
Based on Flange facing Types
Based on Pressure Temperature Ratings
Based on Material Types

Flange Types
Threaded Flanges
Socket-Weld Flanges
Slip-On Flanges
Lap Joint Flanges
Weld Neck Flanges
Blind Flanges

Flange Facing Types
Based on Flange facing Types, it can be further classified as
Flat Face (FF)
Raised Face (RF)
Ring Joint (RTJ)
Tongue and groove (T&G)
And Male and Female type

Serration on the Flange Face
The flange face has small grooves.  This machining is known as a serration.  Flange faces can be smooth or serrated type. It depends on the type of gasket and service of the fluid.

Smooth finish is used with a metallic gasket whereas a serrated finish is used with a non-metallic gasket.  The soft material of gaskets is set in this serration and prevents liquid or gas from passing from the flange joint.

Serration can be spiral or concentric rings as you can see in the slide. Concentric rings type finishing is used when fluid is of very low density. If you use spiral type finish with very low-density fluid, it may find a leakage path through the spiral cavity.

Flange Pressure-Temperature Class (Service Rating)
The flange is classified as per their pressure-temperature ratings which are designated as 150#, 300#, 400#, 600#, 900#, 1500# and 2500#. Large diameter flanges that are 24 to 60 are available up to 900# class. Pressure-temperature ratings are maximum allowable working gauge pressures in the bar & the temperatures in degrees Celsius.

Higher the rating, heavier the flange and can withstand higher pressure and temperature. When the temperature goes up, the pressure goes down, and vice versa. Please note that different material has different pressure ratings.

Flange Material
Flanges are manufactured from

Carbon steel
Low alloy steel
Stainless steel
Combination of Exotic materials (Stub) and other backing materials

List of materials used to manufacture flanges is covered in ASME B16.5 & B16.47.
ASME B16.5 -Pipe Flanges and Flanged Fittings NPS  to 24
ASME B16.47 -Large Diameter Steel Flanges NPS 26 to 60

Commonly used Forged material grades are
Carbon Steel:  ASTM A105, ASTM A350 LF1/2, ASTM A181
Alloy Steel:  ASTM A182F1 /F2 /F5 /F7 /F9 /F11 /F12 /F22
Stainless Steel:  ASTM A182F6 /F304 /F304L /F316 /F316L/ F321/F347/F348

Flange Inspection
Following to be confirmed during an inspection of a flange

Outer & Inner Diameter of body
Bolt Circle & Bolt hole Diameter
Hub Diameter & thickness of weld end
Length of the Hub
Straightness and alignment of the bolt hole
Permissible tolerances are given in B16.5 and B16.47 standards.

Reducing flange is used in place of a standard flange to allow for a change in pipe size. This flange eliminates the need for a standard reducer in piping.  The flange consists of one specified diameter with a smaller diameter bore size. Except for the bore and hub dimensions, a reducing flange has dimensions of the standard pipe flanges size and is considered an economical means to make a pipe size transition.

These flanges available in weld neck, slip-on, and threaded end types. Reducing flanges are an economical way to make transitions between pipes of different sizes, however, due to high-pressure loss; they are rarely used in piping. ASME B16.5 covers the dimensions of the reducing flanges.

Orifice Flanges or ORF are used with orifice flow meter that is why it called orifice flanges. The purpose of orifice meter is to measure the flow rate of either liquids or gasses that pass through the pipe. These flanges are always used in a set of two. Two flanges, Orifice Plate, Gaskets, Pressure taps and Jack screw hole with two jack screws.

Orifice flanges are available from Class #300 to Class #2500. Class #300 flanges are available in threaded, slip-on and weld neck end types. Whereas, Class# 600 and above flanges are available in only weld neck type end connection.  Dimensions of these flanges are covered in ASME B16.36. Orifice plate is a specially designed plate with a hole at center that creates a pressure drop to measure the flow rate. Please note that orifice plate is not interchangeable. It means you cannot use orifice plate of water line into the hydrocarbon line. Size of the hole and the angle, are specifically designed for the service.

There are only two types of flange faces are available in orifice flange. Raised face and RTJ face. Therefore, only spiral wound and RTJ gaskets are used that too in the set of two for each side of the orifice. These jack screws are drilled on the flange circle centerline at 90 degrees to the tapped hole and used to facilitate separating the flanges for inspection or replacement of the Orifice Plate and gaskets.

Tap holes are either tapped  NPT or  NPS socket connection. A one tap hole from each flange is used to connect instruments with the help of tube that allows liquid or gas to reach the instrument. The other one hole is sealed with a plug. Orifice flanges are installed in a straight run of pipe in order to avoid turbulence at the plate. As a rule of thumb, an orifice flange has ten diameters of straight pipe upstream and five diameters of straight pipe downstream. In general pressure taps kept at the same elevation to each other.

Standard: ANSI B16.5
Pressure: CLASS 150, 300, 600, 900, 1500, 2500
Size: 1/2-48
Standard: AMSE B16.47 SER.B(API605)
Pressure: CLASS 75,150,300,600,900
Size: 26-60
Standard: AMSE B16.47
Pressure: CLASS 150,300,600,900

As the name suggests, Long Neck Flange has long neck than regular weld neck flange. Other than neck, all the dimensions are same as the regular flanges. It is used as a nozzle in the pressure vessel and heat exchanger.

Long neck has two advantages over the normal pipe to flange connection. First, it does not require pipe piece and second it eliminates, weld between pipe and flange that required in case of conventional nozzle connection. These types of flanges are normally used in high pressure and temperature application. It is costly but gives high reliability and reduces fabrication efforts as compared to normal pipe to flange type nozzle. 

Standard: ANSI B16.5
Pressure: CLASS 150,300,600,900,1500,2500
Size: 1/2-48
Standard: AMSE B16.47 SER.B (API605)
Pressure: CLASS 75,150,300,600,900
Size: 26-60
Standard: AMSE B16.47 SER.A (MSS SP44)
Pressure: CLASS 150,300,600,900
Size: 12-60

A flange can also be a plate or ring to form a rim at the end of a pipe when fastened to the pipe (for example, a closet flange). A blind flange is a plate for covering or closing the end of a pipe. A flange joint is a connection of pipes, where the connecting pieces have flanges by which the parts are bolted together.

150 lb. Slip-On Plate Flanges

 OD AND DRILLING for  through 24 pipe sizes per ASME/ANSI B16.5-1996 Class 150

 OD AND DRILLING for 30& 36 pipe size per ASME/ANSI B16.1-1989 Class 125

The ANSI B16.5 Class 150 Plate Flanges are meant for both Pipe systems as well as Flanged Fittings. The specification for the ASME B16.5 Plate Flanges covers, dimensions, tolerances, marking, testing, pressure &temperature ratings, materials including methods of designating openings for flanges and flanged fittings in pipe systems. The following points are included:

Plate Flange with pressure rating class designations i.e. class 150, class 300, class 400, class 600, class 900, and class 1500 in a size range between NPS 1/2 up to NPS 24 & Alloy Steel Plate Flanges with pressure rating class designation class 2500 is available in sizes NPS 1/2 till NPS 12.

The requirements of the ASME B16.5 Plate Flange has been given in both metric as well as the U.S. Customary units with diameter of bolts and Plate Flange Dimensions bolt holes expressed in inch units;

Flanged fittings with rating class designation class 400, class 600, class 900, and class 1500 in sizes NPS 1/2 through NPS 24 and ANSI B16.5 Plate Flanges fittings with rating class designation with Stainless Steel Plate Flanges class 2500 in sizes NPS 1/2 up until NPS 12. These have been acknowledged in the specification in Non-Mandatory Appendix E section of the Flat Faced Plate Flanges in which only U.S. Customary units are provided.

ASME B16.5 Plate Flange has been limited to flanges and flanged fittings made from materials such as cast or forged materials. While blind flanges and certain reducing flanges could be manufactured from other metals such as cast, forged, or plate materials are exported by plate flange manufacturers. Also included in this Standard are requirements and recommendations regarding the ASME B16.5 Plate Flange for bolting, flange gaskets, as well as flange joints.

This Standard is to be used by ASME B16.5 Plate Flange manufacturers in conjunction with equipments that have been mentioned in other volumes of the Standards in ASME B16 Series as well as with other ASME standards. Therefore, the ASTM A182 SS Plate Flange could be used for both the Boiler and Pressure Vessel Code as well as the B31 Piping Codes.

PN is an acronym for Pressure Nominale. The PN is used as a prefix to the pressure rating of the Flanges. ... Following international flange standards such as ISO 7005-1 or DIN 2501, PN10, PN16, PN25, and PN40 specify both pressure class in pressure bars and metric flange dimensions that use the metric measuring system

EN 1092-1 is for steel flanges, EN 1092-2 is for iron flanges, EN 1092-3 is for alloy flanges, EN 1092-4 is for aluminum alloy flanges. PN stands for Nominal Pressure and roughly equates to the number of bars i.e. the cold working pressure of PN10 is 10 bar. Ratings range from PN2. 5 to PN420

The Term PN is a Flange standard, they specify the pressure class in bar and metric standard following the metric dimensions. In general Flanges are used for connections with Equipments or Inter connections between the Metallic and Non metallic