Stub End Manufacturer

A stub end is a type of pipe fitting used in various industrial applications to connect pipes or flanges.

It is designed to be welded to the pipe or lap joint flange, providing a secure and leak-proof joint. The stub end itself does not have any threading; instead, it acts as a sleeve that slips over the pipe or lap joint flange. This unique design allows for easy and quick disassembly of the joint when needed.

Pipe Collar

Pipe collars are connectors used to join pipes without welding, providing a secure and efficient piping solution.

A403 WPS304L Stub End

A403 WPS304L stainless stub ends are high-quality pipe fittings, renowned for their strength and corrosion resistance.

Lap Joint Stub End

Lap joint stub ends feature a socket design for easy connection and disconnection in piping systems.

Carbon Steel Stub End

Carbon steel stub ends are robust fittings designed for durability and ease of installation in pipe systems.

Stainless Stub End

Stainless stub ends are corrosion-resistant pipe fittings, suitable for demanding environments and high-pressure systems.

Saddle previously

Saddle fittings, previously known as 'saddle previously', are used for tapping into pipelines to introduce or remove flow.

ASME B16.9 Stub End

ASME B16.9 stub ends are standardized pipe fittings designed for compatibility and reliability in fluid transport.

Types of Stub Ends

Stub end are offered in three different ways, type A, B and C. Type A and B stub end are similar to forged fittings, such as elbows and tees, and type C stub end are made in customized sizes.

Stub ends are manufactured in three different types and two standard length.

Type “A”: this type is produced and machined to fit lap joint flanges.The mating surfaces of the stub end and the lap joint flange have a matching profile and surface. The lap thickness of type A stub ends is > = the minimum wall thickness of the connected pipe. The outside the stub end and the lap joint flange have a matching profile and surface. The lap thickness of type A stub ends is > = the minimum wall thickness of the connected pipe. The outside corner of type A has a radius to accommodate the lap join flange, whereas the inside corner is squared.

Type “B”: this type of stub ends is suited for standard slip-on flanges acting as lap-joint flanges. The lap thickness of type B stub ends is >= the minimum WT of the connecting pipe. The lap of these type of stub ends has generally a serrated face. To ensure tight joints, chamfers on the ID side of the flange are required.

Type “C”: this last type can be used both with lap joint and slip-on backing flanges and are fabricated out of pipes. The lap of C-type stub ends is flared over and the lap thickness is 75% of the connecting pipe WT. Type C has a short fillet outer radius able to host any back up flange.

Type “CS”: this type is similar to “C” with the difference that the lap face has concentric serrations machined during the manufacturing process.

Common Types and Lengths

There are two main types of stub ends commonly used in piping systems:

1. Long Pattern Stub End: A long pattern stub end has a longer length compared to the pipe it is attached to. It is designed to be used with standard lap joint flanges. The long pattern allows for easier alignment and welding of the lap joint flange, making it suitable for applications where frequent disassembly is required.
2. Short Pattern Stub End: A short pattern stub end has a length that is similar to the pipe it is connected to. It is used with slip-on flanges, where the stub end slides over the pipe and is welded in place. The short pattern stub end is ideal for applications where space is limited, and the flange needs to be close to the end of the pipe.

Both long pattern and short pattern stub ends are available in various materials such as stainless steel, carbon steel, alloy steel, and others, making them suitable for different industrial applications. They provide a cost-effective and reliable solution for connecting pipes to flanges in piping systems.

Stub ends dimensions and weight

Dimensions and manufacturing tolerances are covered in ASME B16.9 – Butt Weld Fittings and MSS-SP-43 (JIS B2312, JIS B2313 may also apply).

Stub End come in three standard lengths, MSS SP43 or ANSI B16.9 short and long pattern. Short pattern stub ends are mostly used for flanges from class 300 to class 600 and above. Besides these standard types, End-Users and contractors can require stub ends with non-standard lengths to suit specific project’s requirement. This will of course come at an additional cost.

Ends/Face lap finishing

ASME B16.25 END WELDING BEVEL as right

The following types of ends may be ordered:

Beveled Ends (generally ASME B16.25)
Squared Ends
Flanged Ends
Victaulic Grooves
Threaded Ends (Male Only)

Standard

Pipe fitting dimensions are in either metric or Standard English.

Because pipe fitting covers Pipe Fitting Dimensions several aspects, only the most common pipe fitting sizes can be given here. The most applied version is the 90° long radius and the 45° elbow, while the 90° short radius elbow is applied if there is too little space. The function of a 180° elbow is to change direction of flow through 180°. Both, the LR and the SR types have a center to center dimension double the matching 90° elbows. These fittings will generally be used in furnesses or other heating or cooling units.

Some of the standards that apply to buttwelded fittings are listed below. Many organizations such as ASME, ASTM, ISO, MSS, etc. have very well developed standards and specifications for buttwelded fittings. It is always up to the designer to ensure that they are following the applicable standard and company specification, if available, during the design process.

Some widely used pipe fitting standards are as follows:

ASME: American Society for Mechanical Engineers
This is one of the reputed organizations in the world developing codes and standards.
The schedule number for pipe fitting starts from ASME/ANSI B16. The various classifications of ASME/ANSI B16 standards for different pipe fittings are as follows:

• ASME/ANSI B16.1 – 1998 – Cast Iron Pipe Flanges and Flanged Fittings
• ASME/ANSI B16.3 – 1998 – Malleable Iron Threaded Fittings
• ASME/ANSI B16.4 – 1998 – Cast Iron Threaded Fittings
• ASME/ANSI B16.5 – 1996 – Pipe Flanges and Flanged Fittings
• ASME/ANSI B16.11 – 2001 – Forged Steel Fittings, Socket-Welding and Threaded
• ASME/ANSI B16.14 – 1991 – Ferrous Pipe Plugs, Bushings and Locknuts with Pipe Threads
• ASME/ANSI B16.15 – 1985 (R1994) – Cast Bronze Threaded Fittings
• ASME/ANSI B16.25 – 1997 – Buttwelding Ends
• ASME/ANSI B16.36 – 1996 – Orifice Flanges etc.

ASTM International: American Society for Testing and Materials
This is one of the largest voluntary standards development organizations in the world. It was originally known as the American Society for Testing and Materials (ASTM).

• ASTM A105/A105M – Specification for Carbon Steel Forgings for Piping Applications
• ASTM A234/A234M – Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Moderate and High Temperature Service
• ASTM A403/A403M – Specification for Wrought Austenitic Stainless Steel Piping Fittings
• ASTM A420/A420M – Standard Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Low-Temperature Service

AWWA: American Water Works Association

AWWA About – Established in 1881, the American Water Works Association is the largest nonprofit, scientific and educational association dedicated to managing and treating water, the world’s most important resource.

• AWWA C110 – Ductile-Iron and Gray-Iron Fittings, 3 Inch Through 48 Inch (75 mm Through 1200 mm), for Water and Other Liquids
• AWWA C208 – Dimensions for Fabricated Steel Water Pipe Fittings

ANSI: The American National Standards Institute

ANSI is a private, non-profit organization. Its main function is to administer and coordinate the U.S. voluntary standardization and conformity assessment system. It provides a forum for development of American national standards. ANSI assigns “schedule numbers”. These numbers classify wall thicknesses for different pressure uses.

MSS STANDARDS: Manufacturers Standardization Society
The Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry is a non-profit technical association organized for development and improvement of industry, national and international codes and standards for: Valves, Valve Actuators, Valve Modification, Pipe Fittings, Pipe Hangers, Pipe Supports, Flanges and Associated Seals

• MSS SP-43 – Wrought Stainless Steel Butt-Welding Fittings Including Reference to Other Corrosion Resistant Materials
• MSS SP-75 – Specifications for High Test Wrought Buttwelding Fittings
• MSS SP-73 – Brazing Joints for Copper and Copper Alloy Pressure Fittings
• MSS SP-83 – Class 3000 Steel Pipe Unions, Socket-Welding and Threaded
• MSS SP-97 – Integrally Reinforced Forged Branch Outlet Fittings — Socket Welding, Threaded, and Buttwelding Ends
• MSS SP-106 – Cast Copper Alloy Flanges and Flanged Fittings Class 125,150, and 300
• MSS SP-119 – Factory-Made Wrought Belled End Socket Welding Fittings

Difference between “Standard” and “Codes”:

Piping codes imply the requirements of design, fabrication, use of materials, tests and inspection of various pipe and piping system. It has a limited jurisdiction defined by the code. On the other hand, piping standards imply application design and construction rules and requirements for pipe fittings like adapters, flanges, sleeves, elbows, union, tees, valves etc. Like a code, it also has a limited scope defined by the standard.

Factors affecting standards: “Standards” on pipe fittings are based on certain factors like as follows:

• Pressure-temperature ratings
• Size
• Design
• Coatings
• Materials
• Marking
• End connections
• Dimensions and tolerances
• Threading
• Pattern taper etc.

BSP: British Standard Pipe

BSP is the U.K. standard for pipe fittings. This refers to a family of standard screw thread types for interconnecting and sealing pipe ends by mating an external (male) with an internal (female) thread. This has been adopted internationally. It is also known as British Standard Pipe Taper threads (BSPT )or British Standard Pipe Parallel (Straight) threads (BSPP ). While the BSPT achieves pressure tight joints by the threads alone, the BSPP requires a sealing ring.

JIS: Japanese Industrial Standards

This is the Japanese industrial standards or the standards used for industrial activities in Japan for pipe, tube and fittings and published through Japanese Standards Associations.

NPT: National Pipe Thread

National Pipe Thread is a U.S. standard straight (NPS) threads or for tapered (NPT) threads. This is the most popular US standard for pipe fittings. NPT fittings are based on the internal diameter (ID) of the pipe fitting.

BOLTS & NUTS

We are manufacturer of Flange bolts & Nuts and supply high quality

• A193 = This specification covers alloy and stainless steel bolting material for pressure vessels, Valves, flanges, and fittings for high temperature or high pressure service, or other special purpose applications.
• A320 = Standard Specification for Alloy-Steel and Stainless Steel Bolting Materials for Low-Temperature Service.
• A194 = Standard specification for nuts in many different material types.

AN: Here, “A” stands for Army and “N” stands for Navy

The AN standard was originally designed for the U.S. Military. Whenever, a pipe fitting is AN fittings, it means that the fittings are measured on the outside diameter of the fittings, that is, in 1/16 inch increments.

For example, an AN 4 fitting means a fitting with an external diameter of approximately 4/16″ or ¼”. It is to be noted that approximation is important because AN external diameter is not a direct fit with an equivalent NPT thread.

Dash (-) size

Dash size is the standard used to refer to the inside diameter of a hose. This indicates the size by a two digit number which represents the relative ID in sixteenths of an inch. This is also used interchangeably with AN fittings. For example, a Dash “8” fitting means an AN 8 fitting.

ISO: International Organization for Standardization

ISO is the industrial pipe, tube and fittings standards and specifications from the International Organization for Standardization. ISO standards are numbered. They have format as follows:

“ISO[/IEC] [IS] nnnnn[:yyyy] Title” where

• nnnnn: standard number
• yyyy: year published, and
• Title: describes the subject

General standard

Wide variety for all areas of application

ASTM A234/A234M is a standard specification for piping fittings of wrought carbon steel and alloy steel for moderate and high-temperature service. This specification covers several grades of fittings that are used in various applications in the oil and gas, petrochemical, and power generation industries.

Chemical Composition (%) of ASTM A234/A234M

Notes:

For each reduction of 0.01% below the specified C maximum, an increase of 0.06% Mn above the specified maximum will be permitted, up to a maximum of 1.35%.

The sum of Cu, Ni, Cr, and Mo shall not exceed 1.00%.

The sum of Cr and Mo shall not exceed 0.32%.

The maximum carbon equivalent (C.E.) shall be 0.50, based on heat analysis and the formula C.E.=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15.

Mechanical properties of ASTM A234

What is the ASTM A403?

ASTM A403 Stainless Steel Pipe Fittings refers to the material of forged and rolled austenitic stainless fittings for pressure pipes. Common grades are WP304/L, WP316/L. They can be used into many fields as engineering industry, energy conversion plants etc.

ASTM A403 Standard specification covers the standard for wrought austenitic stainless steel fittings for pressure piping applications.

Chemical Composition (%) of ASTM A403

Notes:

For each reduction of 0.01% below the specified C maximum, an increase of 0.06% Mn above the specified maximum will be permitted, up to a maximum of 1.35%.

The sum of Cu, Ni, Cr, and Mo shall not exceed 1.00%.

The sum of Cr and Mo shall not exceed 0.32%.

The maximum carbon equivalent (C.E.) shall be 0.50, based on heat analysis and the formula C.E.=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15.

Mechanical properties of ASTM A403

Material Furnished to this specification shall conform to the requirements of specifications A960/A960M including any supplementary requirements that are indicates in the purchase order. Failure to company with the common requirements of Specification A960/A960M constitutes non-conformance with this specification . In case of conflict between this specification and Specification A960/A960M , this specification shall prevail.

Material Furnished to this specification shall conform to the requirements of specifications A960/A960M including any supplementary requirements that are indicates in the purchase order. Failure to company with the common requirements of Specification A960/A960M constitutes non-conformance with this specification. In case of conflict between this specification and Specification A960/A960M , this specification shall prevail.

What grade of steel is ASTM A403?

The standard includes several grades of austenitic stainless steel alloys, and uses the WP or CR prefix to mark the grade of steel, depending on the applicable ASTM or MSS size and rated pressure standards. ASTM A403 is designed for forged steel pipe fittings, Cast pipe fittings are not suitable.

Chemical Composition (%) of ASTM A420

Notes:

*For grade WPL6, the limit for Columbium may be increased up to 0.05% on heat analysis and 0.06% on product analysis.

*Fittings of WPL3 made from plate or forgings may have 0.90 % max manganese.

*Fittings of WPL8 made from plate may have 0.98 % max manganese.

Mechanical properties of ASTM A420

*All the elongation values are on the basis of standard round specimen, or small proportional specimen, min % in 4 D.

ASTM A234 is Standard Specification for steel pipe fittings includes carbon and alloy steel material for moderate and high temperature services.

ASME / ANSI B16.9 dimension

ASME B16.9 Standard covers overall dimensions, tolerances,ratings, testing, and markings for factory-made wrought buttwelding fittings in sizes NPS 1⁄2 through NPS 48 (DN 15 through DN 1200).

Tolerances of Welded Fittings

All dimensions are given in inches. Tolerances are equal plus and minus except as noted.

1. Out-of-round is the sum of absolute values of plus and minus tolerance.
2. This tolerance may not apply in localized areas of formed fittings where increased wall thickness is required to meet design requirements of ASME B16.9.
3. The inside diameter and the nominal wall thicknesses at ends are to be specified by the purchaser.
4. Unless otherwise specified by the purchaser, these tolerances apply to the nominal inside diameter, which equals the difference between the nominal outside diameter and twice the nominal wall thickness.

The ASME B16.9 pipe fittings can be used under the jurisdiction of the ASME Boiler & Pressure Vessel Code (BPVC) as well as the ASME Code for pressure piping. Referencing pressure ratings of flanges per ASME B16.5, they can be designated as Classes 150, 300, 600, 900, 1500 and 2500. The allowable pressure ratings for ASME B16.9 pipe fittings may be calculated as for straight seamless pipe of equivalent material in accordance with the rules established in the applicable sections of ASME B31 Code for pressure piping.

Design of Fittings

The design of butt welding pipe fittings made to ASME B16.9 shall be established by one of the following methods: (a) mathematical analyses contained in pressure vessel or piping codes; (b) proof testing; (c) experimental stress analysis with hydrostatic testing to validate experimental results; (d) detailed stress analysis with results evaluation.

Standard Marking

Generally, ASME B16.9 pipe fittings shall be marked to show the following details: “trademark + material grade + wall thickness + size + heat number”. For example, “M ASTM A234 WP5 SCH80 6″ 385“. When steel stamps are used, care shall be taken so that
the marking is not deep enough or sharp enough to cause cracks or to reduce the wall thickness of the fitting below the minimum allowed.

Material & Manufacture

The ASME B16.9 fittings may be made from an extensive range of mateirals covering (1) carbon and low-alloy steels in accordance with ASTM A234 and ASTM A420; (2) austenitic and duplex stainless steels in accordance with ASTM A403 and ASTM A815; (3) nickel alloys in accordance with ASTM B366; (4) aluminum alloys in accordance with ASTM B361; and (5) titanium alloys in accordance with ASTM B363.

Pipe Fittings Dimensions Tolerance as per ASME B16.9:

Sizes 1/2″ – 48″

• ASME / ANSI B16.9 Butt Weld Elbow – Long Radius
• ASME / ANSI B16.9 Butt Weld Elbow – Short Radius
• ASME / ANSI B16.9 Butt Weld Reducing Elbow
• ASME / ANSI B16.9 Butt Weld 45° Elbow
• ASME / ANSI B16.9 Butt Weld Fabricated Tee
• ASME / ANSI B16.9 Butt Weld Reducer
• ASME / ANSI B16.9 Butt Weld Concentric Reducer
• ASME / ANSI B16.9 Butt Weld Eccentric Reducer
• ASME / ANSI B16.9 Butt Weld 3D Elbow
• ASME / ANSI B16.9 Butt Weld Stub Ends
• ASME / ANSI B16.9 Butt Weld Cross
• ASME / ANSI B16.9 Butt Weld Reducing Cross
• ASME / ANSI B16.9 Butt Weld Tees
• ASME / ANSI B16.9 Butt Weld End Cap
• ASME / ANSI B16.9 Butt Weld Coupling
• ASME / ANSI B16.9 Butt Weld Pipe Nipple
• ASME / ANSI B16.9 Butt Weld 5D Elbow
• ASME / ANSI B16.9 Butt Welded Pipe Fittings

MSS SP-97

MSS SP-97 Standard Practice covers essential dimensions, finish, tolerances, testing, marking, material, and minimum strength requirements for 90 degree integrally reinforced forged branch outlet fittings of buttwelding, socket welding, and threaded types.

Chemical Composition Requirements of MSS SP 75

*1. The sum of Cu, Ni, Cr and Mo shall not exceed 1%.

*2. Carbon equivalent C.E.=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15 shall not exceed 0.45%.

Industrial Applications

Stub end is widely used in the petroleum, chemical, power, gas, metallurgy, shipbuilding and construction industries. It is made from high quality raw materials, and available in a variety of sizes and designs.

Electric power industry

Petrochemical Industry

Instrumentation and Electronics

Mechanical Equipment

Shipbuilding Manufacturing

Ocean Engineering

Food & Pharmaceuticals

Clean Gas

Papermaking Industry

Vehicle Traffic

Environmental Management

Municipal Engineering

The use of stub ends has these two advantages:

Stub end is widely used in the petroleum, chemical, power, gas, metallurgy, shipbuilding and construction industries. It is made from high quality raw materials, and available in a variety of sizes and designs. The combination of stub ends and backing flanges is an alternative way to join pipes compared to the use of standard flanges.

90° Lateral Wye R500 DN150 Export to Pilipinas with lap-joint flanges

This solution is used in these typical scenarios:

• Applications where rotating back flanges are preferred (to facilitate bolting)
• Pipelines in costly materials, as stainless steel, duplex, super-austenitic (example 6Mo), nickel alloy, titanium and zirconium: indeed, the use of stub ends for this type of pipelines helps End-Users and EPC Contractors reduce the total weight of the flanged joints and their total cost (example: in a stainless steel pipeline, carbon steel backing flanges can be used instead of standard stainless steel flanges – as they do not get in contact with the fluid conveyed by the pipeline – “unwetted materials”)
• High pressure pipelines

Delivery

Inspection

Visual Inspection is conducted on fittings to check any surface imperfections. Both fittings body and weld are checked for any visible surface imperfections such as dents, die marks, porosity, undercuts, etc. Acceptance as per applicable standard.

Packing

For packing of carbon steel flanges with painting,we would use the bubble wrap to protect the painting.For flanges without painting or oiled with long-term shipment,we would suggest client to use the anti-tarnish paper and plastic bag to prevent the rust.