The types of pipe flange

A pipe flange is disc, collar or ring that attaches to pipe with the purpose of providing increased support for strength, blocking off a pipeline or implementing the attachment of more items. Pipe flanges are usually welded or screwed to the pipe end and are connected with bolts. A gasket is inserted between the two mating flanges to provide a tighter seal. Pipe flanges are either custom with dimensions provided by the customer or they are manufactured according to published specifications. Several organizations and associations have published specifications that provide dimensional information as well as pressure specifications at different temperatures.

Sunny Steel manufactures custom flanges and stocks 6 basic types of pipe flanges. Although, these are the 6 most common types of pipe flanges, Sunny Steel is a custom flange manufacturer as well and is able to create just about any type of flange necessary for your requirements.

SLIP-ON PIPE FLANGES >>

Slip-on pipe flanges actually slip over the pipe. These pipe flanges are typically machined with an inside diameter of the pipe flange slightly larger than the outside diameter of the pipe. This allows the flange to slide over the pipe but to still have a somewhat snug fit. Slip-on pipe flanges are secured to the pipe with a fillet weld at the top and the bottom of the slip-on pipe flanges. These pipe flanges are also further categorized as a ring or a hub. Ring pipe flanges and hub pipe flanges are both considered slip on pipe flanges because they both slip over the pipe. Slip on Pipe flanges with a hub have published specifications that range from 1/2″ thru 96″. Slip on pipe flanges that consist of a flat ring have published specifications that range from 1/2″ to 144″. Sunny Steel provides Slip-On pipe flanges in all material grades, specifications and sizes.

WELD NECK PIPE FLANGES >>

Weld neck pipe flanges attach to the pipe by welding the pipe to the neck of the pipe flange. This allows for the transfer of stress from the weld neck pipe flanges to the pipe itself. This also reduces high stress concentration at the base of the hub of the weld neck pipe flanges. Weld neck pipe flanges are often used for high pressure applications. The inside diameter of a weld neck pipe flange is machined to match the inside diameter of the pipe. Weld Neck Pipe flanges with a hub have published specifications that range from 1/2″ to 96″. Sunny Steel provides Weld Neck pipe flanges in all material grades, specifications and sizes.

BLIND PIPE FLANGES >>

Blind pipe flanges are pipe flanges used to seal the end of a piping system or pressure vessel openings to prevent flow. Blind pipe flanges are commonly used for pressure testing the flow of liquid or gas through a pipe or vessel. Blind pipe flanges also allow easy access to the pipe in the event that work must be done inside the line. Blind pipe flanges are often used for high pressure applications. Slip on Pipe flanges with a hub have published specifications that range from 1/2″ to 96″. Sunny Steel provides Blind pipe flanges in all material grades, specifications and sizes.

LAP JOINT PIPE FLANGES >>

Lap Joint Pipe Flanges slide over the pipe and are most commonly used with Stub End Fittings. A pipe is typically welded to the Stub End and the Lap Joint pipe flange is free to rotate around the stub end. The benefit of this is that there will not be any issues with bolt hole alignment. Lap Joint pipe flanges are often used for applications that require frequent dismantling. Slip on Pipe flanges with a hub have published specifications that range from 1/2″ to 24″. Sizes above 24″ are produced as lap joints to slip on dimensions. Sunny Steel provides Lap Joint pipe flanges in all material grades, specifications and sizes.

THREADED PIPE FLANGES >>

Threaded pipe flanges are similar to slip-on pipe flanges except the bore of threaded pipe flange has tapered threads. Threaded pipe flanges are used with pipes that have external threads. The benefit of these pipe flanges is that it can be attached without welding. Threaded pipe flanges are often used for small diameter, high pressure requirements. Slip on Pipe flanges with a hub have published specifications that range from 1/2″ to 24″. Sunny Steel provides Threaded pipe flanges in all material grades, specifications and sizes.


SOCKET-WELD PIPE FLANGES >>

Socket-weld pipe flanges are typically used on smaller sizes of high pressure pipes. These pipe flanges are attached by inserting the pipe into the socket end and applying fillet weld around the top. This allows for a smooth bore and better flow of the fluid or gas inside of the pipe. Slip on Pipe flanges with a hub have published specifications that range from 1/2″ to 24″. Sunny Steel provides Socket Weld pipe flanges in all material grades, specifications and sizes.

Dimensions of spectacle blinds according to ASME B16.48

Dimensions of spectacle blinds according to  B16.48 for installation between B16.5 flanges.
Material SymbolCMnPSSiNiCrMoCuNVCo
ASTM A1050.350.60-1.050.0350.040.10-0.350.40.30.120.4_0.08_
ASTM A350 LF20.30.60-1.350.0350.040.15-0.300.40.30.120.4_0.080.02
ASTM A182 F3040.0820.0450.0318.0-11.018.0-20.0_____
ASTM A182 F304L0.0320.0450.0318.0-13.018.0-20.0_____
ASTM A182 F3160.0820.0450.03110.0-14.016.0-18.02.00-3.00____
ASTM A182 F316L0.0320.0450.03110.0-15.016.0-18.02.00-3.00____
ASTM A182 F3210.0820.0450.0319.0-12.017.0-19.0_____
EN 10025 S235JR0.21.40.0450.045_____0.01__
20Mn0.17-0.230.70-1.000.0350.0350.17-0.370.30.250.25
200.17-0.230.60-1.000.030.020.17-0.370.250.250.25
16Mn0.13-0.191.20-1.600.030.020.20-0.600.30.30.25
Material SymbolTensile Strength, min, MPaYield point, min, MpaElongation, min, %Reduction of area, min, %Hardness, max, HBMin. ImpactTest Temperature, °C
ASTM A1054852502230187
ASTM A350 LF2485-655250223020-46
ASTM A182 F3045152053050
ASTM A182 F304L4851703050
ASTM A182 F3165152053050
ASTM A182 F316L4851703050
ASTM A182 F3215152053050
20Mn4502752450197
204102452555156

Raised Face Joint Blanks

Raised Face Joint Blanks
Raised Face Joint Blanks
  • ASME B16.48 says: The gasket seating surface finish and dimensions for raised face line blanks shall be in accordance with ASME B16.5. A raised face may be specified at the option of the purchaser.
  • A Raised Face would add machining time and complexity so the price would be higher. Call this the Bugatti or Rolls Royce of the line blind world.
  • Personally, I have seen that version once or twice somewhere. The version without Raised Face is the default and is used everywhere.

Flange Types

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.
Below are our available industrial pipe flanges that will meet your project needs. We will help you put together your entire project and ship it to your closest port.

We ship globally! Contact us to speak with one of our experienced staff, who can help you with your project needs.
Blind Flanges
Blind Flanges>>
The blind flange is used to close ends of piping systems. It is a kind of round plate with no center hold but with all the proper bolt holes.
Bending
Figure-8 Blanks >>
A figure-8 blank (also called a Spectacle Blind Flange) is a pressure-retaining plate with one solid end and one open end connected with a web or tie bar.
Pipe tees
Lap Joint Flanges >>
The lap joint flange is practically identical to a slip-on flange except it has a radius at the intersection of the bore and flange face.
Pipe cross
Orifice Flanges >>
Orifice flanges are used instead of the standard pipe flanges when orifice plate or flow nozzle is used.
End caps
Reducing Flanges >>
Reducing flanges are used in pipe-to-pipe connections. Reducing flanges are a little easier to bolt up than non-reducing flanges.
Pipe reducer
RTJ Flanges >>
Ring Type Joint Flange is a method of ensuring leak proof flange connection at high pressures.
Stub end
Socket Welding Flanges >>
The socket welding flange is similar to a slip-on flange except it has a bore and a counterbore dimension.
Coupling Fittings
Slip-On Flanges >>
The Slip-on flange has a low hub because the pipe slips into the flange prior to welding.
Coupling Fittings
Threaded Flanges >>
Threaded (Screwed) flange is similar to the Slip-On flange, but the bore is threaded.
Coupling Fittings
Welding Neck Flanges >>
The Welding neck flanges is normally referred to as the high hub flange.
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. In addition, flanges, like fittings and pipes, for specific purposes sometimes internally equipped with layers of materials of a completely different quality as the flanges themselves, which are "lined flanges".  The material of a flange, is basically set during the choice of the pipe, in most cases, a flange is of the same material as the pipe. All flanges, discussed on this website fall under the ASME en ASTM standards, unless otherwise indicated. ASME B16.5 describes dimensions, dimensional tolerances etc. and ASTM the different material qualities.

Size: 1/2" NB To 24" NB.
Class: 150#, 300#, 600#, 900#, 1500# & 2500#.

In addition, we also can produce the DIN flange, and the forgings according to the customers drawings, for example, rings and shafts.
Delivery requirment:
Marking: SunnySteel, material grade, standard, specification, heat no.
Surface Treatment: Bright annealed, polished outside and inside surface.
Package: Each pipe in a PVC bag and caps on both ends then bundled in wood case, (option: Bundle with knitted plastic bag/stee crate. )
Inspection: Third party inspection, or by clints

ASTM A350 Standard Specification


ASTM A350 is the Standard Specification for Carbon and Low-Alloy Steel Forgings, Requiring Notch Toughness Testing for Piping Components


This specification covers several grades of carbon and low alloy steel forged or ring-rolled flanges, forged fittings and Valves for low-temperature service. The steel specimens shall be melt processed using open-hearth, basic oxygen, electric furnace or vacuum-induction melting. A sufficient discard shall be made to secure freedom from injurious piping and undue segregation. The materials shall be forged and shall undergo heat treatment such as normalizing, tempering, quenching and precipitation heat treatment. Heat analysis and product analysis shall be performed wherein the steel materials shall conform to the required chemical compositions of carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, copper, columbium, vanadium, and nitrogen. The materials shall also undergo tension tests and shall conform to the required values of tensile strength, yield strength and elongation. Impact tests shall also be performed and the steel materials shall conform to the required values of minimum impact energy, temperature, and minimum equivalent absorbed energy. Hardness and hydrostatic tests shall also be performed.


Scope
1.1 This specification covers several grades of carbon and low-alloy steel forged or ring-rolled flanges, forged fittings and Valves intended primarily for low-temperature service and requiring notch toughness testing. They are made to specified dimensions, or to dimensional standards, such as the ASME and API Specifications referenced in Section . Although this specification covers some piping components machined from rolled bar and seamless tubular materials (see ), it does not cover raw material produced in these product forms.
1.2 No limitation on size is intended beyond the ability of the manufacturer to obtain the specified requirements. However, Class 3 of Grade LF787 is only available in the quenched-and-precipitation heat treated condition.
1.3 Supplementary requirements are provided for use when additional testing or inspection is desired. These shall apply only when specified by the purchaser in the order.
1.4 This specification is expressed in both inch-pound units and in SI units. However, unless the order specifies the applicable “M” specification designation (SI units), the material shall be furnished to inch-pound units.
1.5 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. Note 1Refer to Test Methods and Definitions A 370 for notes on significance of notched-bar impact testing.

Referenced Documents

  • A370 Test Methods and Definitions for Mechanical Testing of Steel Products
  • A788/A788M Specification for Steel Forgings, General Requirements
  • A961/A961M Specification for Common Requirements for Steel Flanges, Forged Fittings, Valves, and Parts for Piping Applications
  • 600 Steel Gate Valves with Flanged or Butt-Welding Ends
  • 602 Compact Design Carbon Steel Gate Valves for Refinery Use
  • 605 Large Diameter Carbon Steel Flanges
  • A5.1 Mild Steel Covered Arc-Welding Electrodes
  • A5.5 Low-Alloy Steel Covered Arc-Welding Electrodes
  • B16.10 Face-to-Face and End-to-End Dimensions of Ferrous Valves
  • B16.11 Forged Steel Fittings, Socket-Welding and Threaded
  • B16.30 Unfired Pressure Vessel Flange Dimensions
  • B16.34 Valves-Flanged, Threaded, and Welding End
  • B16.47 Large Diameter Steel Flanges
  • B16.5 Steel Pipe Flanges and Flanged Fittings
  • B16.9 Factory-Made Wrought Steel Butt-Welding Fittings
  • Section IX Welding Qualifications

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Sunny Steel provide a wide range of steel products as Steel pipes, Seamless tube and seamless pipes, Alloy pipes, Pipe fittings, Composite steel pipe used in the industry, construction etc.
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