DIN DN40 Pn16 F304 Stainless Steel Stub End Flange Lap Joint Flange

Min.Order: 50
Product origin: Baoding, Hebei, China
Infringement complaint: complaintComplaint
US$ 2

Description

Lap Joint Flanges

Lap Joint Flanges (LJ Flanges) are used on piping fitted with lapped pipe or with lap joint stub ends the combined initial cost of the two items being approximately one-third higher than that of comparable welding neck flanges.

Material: Carbon, Alloy and Stainless Steel
Standards: ASTM A105, ASTM A182
Sizes: 1/2'' to 24''
Thickness: SCH 10, SCH 40, SCH 160
Pressure Ratings: Class 150 to 2500
Face Type: RF, RTJ

Lap joint flange is used with a lap joint stub end fitting. Lap joint flange is similar to a slip-on flange, but with two differences. The radius and the flat face, both allow the flange to secure against the stub end fitting. This is useful where alignment of bolt holes is difficult, such as with spools to be attached to flanged nozzles of vessels. A lap joint is used in low pressure applications and not suitable where high external of heavy loads are present.

These flanges are always used with either a stub end or taft which is butt welded to the pipe with the flange loose behind it. This means the stub end or taft always makes the face. The lap joint is favoured in low pressure applications because it is easily assembled and aligned. To reduce cost these flanges can be supplied without a hub and/or in treated, coated carbon steel.

Lap joint flanges are usually used in low pressure applications and are not suitable when there are high loads on the flange pair. Some types of piping require the use of lap joint flanges. For example, metallic pipe that has been plastic lining may have lap joint flanges.

Using lap joint flanges might be an option for saving costs when the piping is made of exotic materials. By using a lap joint flange, the wetted materials would consist of the exotic materials and the flange would be carbon steel. Since the flange doesn't ever come in contact with the process fluid, it would not be affected by the fluids.

Dimensions on the lap joint flange are similar to weld neck, slip on or socket weld flanges. The backing flange has the same number of bolt holes, size and thickness of a weld neck or slip on flange.

Lap joint flange (simplified as LTF flange) shape is similar to slip on flange, it has a curved radius at the bore, which can connect with a stub end fittings and slide over the pipe. In this form, the pipe is usually welded to this stub end so the lap joint flange can rotate freely around the stub end.

The advantage of this combination that it will be easy with alignment for the bolt hole, easy to install and uninstall, much more convenient to do examinations and maintenance.

Stub End - Key Fittings for Lap Joint Flange

A stub end is always used with a lap joint flange as a backing flange. There are three different types of stub ends, type A, B and C.

  • Type A stub end can be machined to fit the standard lap joint support flange.
  • Type B stub end is designed to be used with standard slip on flange.
  • Either a lap joint flange or slip on flange, the type C stub end can be used

Stub end include long or short pattern length. The end of long pattern is also known as ASA Stub Ends. The short end is used with the larger flanges of ANSI 300 and 600. They are commonly used in most sizes ANSI 900 and above.

Benefits of using Ring Lap Joint Flange

  • Compatible with frequently dismantling. You can remove the pipe easily and frequently for inspection and cleaning purposes. 
  • Easy to rotate flanges and align bolt holes, which simplifies assembly of large diameter or unusually stiff pipes.
  • Cost saving. If the pipe material in alloy steel or stainless steel. By using a lap flange, the wetting material consists of a special material and the flange will be carbon steel. Since the flange does not come into contact with the process fluid, it is not affected by the fluid.
  • Rescue. In systems that are rapidly corroded or corroded, the flange can be recycled for reuse.

Differences between lap joint flange and slip on flange

Slip on flange is essentially a ring placed over the pipe end. And the flange face extending a sufficient distance from the pipe end, so as to apply a weld on the inner diameter. The outer diameter of slip on flange can also be welded to the rear side of flange. Comparing to weld neck flange, slip on flange has lower material cost and easier to align.

The lap flange is very similar to a slip on flange. From the outside, it almost looks like the same. But you look on the backside, the holes and faces of lap joint flange has a curved radius to accommodate the lap joint stub end.

If type B or type C stub end is used, the slip on flange can be used as the lap joint flange.

Lap joint flange datasheets

The datasheets we have on this site are shown below. For simplicity sake, only datasheets that adhere to B16.5 are shown. ASME B16.5 covers flange dimensions from ½" to 24". For sizes larger than this (ASME B16.47 Series A & B), please visit our flange datasheets page.

ClassFlat Face
ANSI 150Lap Joint, ANSI Class 150 (in)
ANSI 300Lap Joint, ANSI Class 300 (in)
ANSI 400Lap Joint, ANSI Class 400 (in)
ANSI 600Lap Joint, ANSI Class 600 (in)
ANSI 900Lap Joint, ANSI Class 900 (in)
ANSI 1500Lap Joint, ANSI Class 1500 (in)
ANSI 2500Lap Joint, ANSI Class 2500 (in)

Lap joint flange with stub end

 

 

 

    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;

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

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

      • ASME B16.5 -Pipe Flanges and Flanged Fittings NPS ½" to 24"
      • ASME B16.47 -Large Diameter Steel Flanges NPS 26" to 60"

      Commonly used Forged material grads 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

      Frequently used astm grades

      MaterialFittingsFlangesValvesBolts & Nuts
      Carbon SteelA234 Gr WPAA105A216 Gr WCBA193 Gr B7
      A194 Gr 2H
      A234 Gr WPBA105A216 Gr WCB
      A234 Gr WPCA105A216 Gr WCB
      Carbon Steel
      Alloy
      High-Temp
      A234 Gr WP1A182 Gr F1A217 Gr WC1A193 Gr B7
      A194 Gr 2H
      A234 Gr WP11A182 Gr F11A217 Gr WC6
      A234 Gr WP12A182 Gr F12A217 Gr WC6
      A234 Gr WP22A182 Gr F22A217 Gr WC9
      A234 Gr WP5A182 Gr F5A217 Gr C5
      A234 Gr WP9A182 Gr F9A217 Gr C12
      Carbon Steel
      Alloy Low-Temp
      A420 Gr WPL6A350 Gr LF2A352 Gr LCBA320 Gr L7
      A194 Gr 7
      A420 Gr WPL3A350 Gr LF3A352 Gr LC3
      Austenitic Stainless SteelA403 Gr WP304A182 Gr F304A182 Gr F304A193 Gr B8
      A194 Gr 8
      A403 Gr WP316A182 Gr F316A182 Gr F316
      A403 Gr WP321A182 Gr F321A182 Gr F321
      A403 Gr WP347A182 Gr F347A182 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

      • ASME B16.1 - Gray Iron Pipe Flanges and Flanged Fittings: Classes 25, 125, and 250
      • ASME B16.5 - Pipe Flanges and Flanged Fittings: NPS 1/2 through NPS 24 Metric/Inch Standard
      • ASME B16.20 - Ring Joint Gaskets and Grooves for Steel Pipe Flanges
      • ASME B16.21 - Nonmetallic Flat Gaskets for Pipe Flanges
      • ASME B16.24 - Cast Copper Alloy Pipe Flanges and Flanged Fittings: Classes 150, 300, 600, 900, 1500, and 2500
      • ASME B16.34 - Large Diameter Steel Flanges (NPS 26 through NPS 60)
      • ASME B16.36 - Orifice Flanges
      • ASME B16.42 - Ductile Iron Pipe Flanges and Flanged Fittings: Classes 150 and 300
      • ASME B16.47 - Large Diameter Steel Flanges (NPS 26 Through NPS 60)

      ASTM standards

      • ASTM A105 - Specification for Carbon Steel Forgings for Piping Applications
      • ASTM A182 - Specification for Forged or Rolled Alloy Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High Temperature Service
      • ASTM A193 - Specification for Alloy Steel and Stainless Steel Bolting Materials for High Temperature Service
      • ASTM A194 - Specification for Carbon and Alloy Steel Nuts for Bolts for High Pressure and High Temperature Service
      • ASTM A694 - Specification for Carbon and Alloy Steel Forgings for Pipe Flanges, Fittings, Valves, and Parts for High-Pressure Transmission Service
      • ASTM A707 - Specification for Flanges, Forged, Carbon and Allow Steel for Low Temperature Service

      AWWA standards

      • AWWA C115 - Standard for Flanged Ductile Iron Pipe with Ductile-Iron or Gray-Iron Threaded Flanges

      ISO standards

      • ISO 5251 - Stainless steel butt-welding fittings

      MSS standards

      • MSS SP-6 - Standard Finishes for Contact Faces Pipe Flanges and Connecting End Flanges of Valves and Fittings
      • MSS SP-9 - Spot Facing for Bronze, Iron and Steel Flanges
      • MSS SP-25 - Standard Marking Systems for Valves, Fittings, Flanges, and Unions
      • MSS SP-44 - Steel Pipeline Flanges
      • MSS SP-53 - Quality Standards for Steel Castings and Forgings for Valves, Flanges and Fittings and Other Piping Components - Magnetic Particle
      • MSS SP-54 - Quality Standards for Steel Castings and for Valves, Flanges and Fittings and Other Piping Components - Radiographic
      • MSS SP-55 - Quality Standards for Steel Castings and for Valves, Flanges and Fittings and Other Piping Components - Visual
      • MSS SP-75 - High Test Wrought Butt Welding Fittings
      • MSS SP-106 - Cast Copper Alloy Flanges and Flanged Fittings Class 125,150, and 300
      • ASME B16.5 and ASME B16.47 cover pipe flanges up to NPS 60 (B16.5 from 1/2″ to 24″ and B16.47 from 26″ to 60″). ANSI
      • B16.47 covers two series of flanges, Series A is equal to MSS SP-44-44, and Series B is equal to API 605 (API 605 has been canclled).

      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.

      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?

      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;

      • 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

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

      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.



















































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