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FLANGE FACE FINISH The ASME B16.5 code requires that the flange face (raised face and flat face) has a specific roughness to ensure that this surface be compatible with the gasket and provide a high quality seal. A serrated finish, either concentric or spiral, is required with 30 to 55 grooves per inch and a resultant roughness between 125 and 500 micro inches. This allows for various grades of surface finish to be made available by flange manufactures for the gasket contact surface of metal flanges. •  THE MOST USED SURFACES ARE 1. Stock Finish The most widely used of any flange surface finish, because practically, is suitable for all ordinary service conditions. Under compression, the soft face from a gasket will embed into this finish, which helps create a seal, and a high level of friction is generated between the mating surfaces. The finish for these flanges is generated by a 1.6 mm radius round-nosed tool at a feed rate of 0.8 mm per revolution up to 12 inch. For sizes 14 inch and larger, the finish is made with 3.2 mm round-nosed tool at a feed of 1.2 mm per revolution. 2. Spiral Serrated This is also a continuous or phonographic spiral groove, but it differs from the stock finish in that the groove typically is generated using a 90-deg tool which creates a “V” geometry with 45° angled serration. 3. Concentric Serrated As the name suggests, this finish is comprised of concentric grooves. A 90° tool is used and the serrations are spaced evenly across the face. 4. Smooth Finish This finish shows no visually apparent tool markings. These finishes are typically utilized for gaskets with metal facings such as double jacketed, flat steel and corrugated metal. The smooth surfaces mate to create a seal and depend on the flatness of the opposing faces to effect a seal. This is typically achieved by having the gasket contact surface formed by a continuous (sometimes called phonographic) spiral groove generated by a 0.8 mm radius round-nosed tool at a feed rate of 0.3 mm per revolution with a depth of 0.05 mm. This will result in a roughness between Ra 3.2 and 6.3 micrometers (125 – 250 micro inch).

On the image above a set Orifice Flange is shown, where the tappings are sealed with a plug, and where a jack screw is machined. This jack screw is used to facilitate separating the flanges for inspection or replacement of the “Orifice Plate” and gaskets. The range of orifice flange covers all standard sizes and ranges, and all common flange materials.Flanges are available in Welding Neck, Slip On, and Threaded form, and are typically supplied with two ½” NPT tappings in each flange. Notes: 1. The American National Pipe Thread Tapered NPT is the best known and most widely used connection where the pipe thread provides both the mechanical joint and the hydraulic seal. NPT has a tapered male and female thread which seals with Teflon tape or jointing compound. 2. ASME B1.20.1 covers dimensions and gaging of NPT pipe threads for general purpose applications. ASME B16.36 covers Dimensions and dimensional tolerances from orifice flanges (similar to those covered in ASME B16.5) that have orifice pressure differential connections. Coverage is limited to the following flanges: Welding Neck Classes 300, 400, 600, 900, 1500, 2500 Threaded Class 300 Slip On Class 300

SOCKET WELD FITTINGS A Socket Weld Fitting is a pipe attachment detail in which a pipe is inserted into a recessed area of a valve, fitting or flange. In contrast to buttweld fittings, socket weld fittings are mainly used for small pipe diameters (Small Bore Piping); generally for piping whose nominal diameter is NPS 4 or smaller. To join pipe to valves and fittings or to other sections of pipe, fillet-type seal welds be used. Socket-welded Joints construction is a good choice wherever the benefits of high leakage integrity and great structural strength are important design considerations. Fatigue resistance is lower than that in butt-welded construction due to the use of fillet welds and abrupt fitting geometry, but it is still better than that of most mechanical joining methods • DETAILS OF SOCKET WELD FITTINGS SW Fittings are family of high pressure fittings are used in various industrial processes. 1. They are used for lines conveying flammable, toxic or expensive material where no leakage can be permitted, and for steam 300 to 600 PSI. 2. They are used only in conjunction with ASME Pipe and are available in the same size range. 3. They are used in areas where pipe-work is permanent and are designed to provide good flow characteristics. 4. They are are produced to several ASTM standards and are manufactured in accordance with ASME B16.11. The B16.11 standard covers pressure-temperature ratings, dimensions, tolerances, marking, and material requirements for forged carbon and alloy steel fittings. Acceptable material forms are forgings, bars, seamless pipe, and seamless tubes which conform to the fittings chemical compositions, melting practices, and mechanical property requirements of ASTM A105, A182, or A350. 5.They are available in three pressure ratings: 3000lbs, 6000lbs and 9000lbs. • TYPES OF SOCKET WELD FITTINGS BY CLASS, SIZE AND WALL THICKNESSDescriptionClass Designation3000 Lbs6000 Lbs9000 LbsElbows 45 degree,  Elbow 90 degree, Tees, Crosses, Couplings, Half-Couplings, End or Pipe Caps½ – 4½ – 2½ – 2½ – 4½ – 2½ – 2½ – 4½ – 2½ – 2Pipe Size by Wall ThicknessSCH 80 & XSSCH 160XXS Plugs and Bushings are not identified. They may be used up through Class 6000 NPS • ADVANTAGES AND DISADVANTAGES OF SOCKET WELD FITTINGS –Advantages 1. The pipe need not be beveled for weld preparation. 2. Temporary tack welding is no needed for alignment, because in principle the fitting ensures proper alignment. 3. The weld metal can not penetrate into the bore of the pipe. 4. They can be used in place of threaded fittings, so the risk of leakage is much smaller. 5. Radiography is not practical on the fillet weld; therefore correct fitting and welding is crucial. The fillet weld may be inspected by surface examination, magnetic particle (MP), or liquid penetrant (PT) examination methods. 6. Construction costs are lower than with butt-welded joints due to the lack of exacting fit-up requirements and elimination of special machining for butt weld end preparation. –Disadvantages 1. The welder should ensure for a expansion gap of 1/16 inch (1.6 mm) between de pipe and the shoulder of the socket. ASME B31.1 para. 127.3 Preparation for Welding (E) Socket Weld Assembly says: In assembly of the joint before welding, the pipe or tube shall be inserted into the socket to the maximum depth and then withdrawn approximately 1/16″ (1.6 mm) away from contact between the end of the pipe and the shoulder of the socket. 2. The expansion gap and internal crevices left in socket-welded systems promotes corrosion and make them less suitable for corrosive or radioactive applications where solids buildup at the joints may cause operating or maintenance problems. Generally require butt welds in all pipe sizes with complete weld penetration to the inside of the piping. 3. Socket weld is unacceptable for UltraHigh Hydrostatic Pressure (UHP) in Food Industry application since they do not permit full penetration and leave overlaps and crevices that are very difficult to clean, creating virtual leaks. The purpose for the bottoming clearance in a socket weld is usually to reduce the residual stress at the root of the weld that could occur during solidification of the weld metal, and to allow for differential expansion of the mating elements.

BUTTWELD FITTINGS butt weld fittings are defined as a part used in a piping system, for changing direction, branching or for change of pipe diameter, and which is mechanically joined to the system. There are many different types of fittings and they are the same in all sizes and schedules as the pipe. Fittings are pided into three groups: 1.Buttweld (BW) fittings  whose dimensions, dimensional tolerances et cetera are defined in the ASME B16.9 standards. Light-weight corrosion resistant fittings are made to MSS SP43. 2.Socket Weld (SW) fittings  Class 3000, 6000, 9000 are defined in the ASME B16.11 standards. 3.Threaded (THD) fittings     Class 2000, 3000, 6000 are defined in the ASME B16.11 standards. • APPLICATIONS OF BUTTWELD FITTINGS A piping system using buttweld fittings has many inherent advantages over other forms. 1. Welding a fitting to the pipe means it is permanently leakproof  2. The continuous metal structure formed between pipe and fitting adds strength to the system 3. Smooth inner surface and gradual directional changes reduce pressure losses and turbulence and minimize the action of corrosion and erosion  4. A welded system utilizes a minimum of space • BEVELLED ENDS The ends of all buttweld fittings are bevelled, exceeding wall thickness 4 mm for austenitic stainless steel, or 5 mm for ferritic stainless steel. The shape of the bevel depending upon the actual wall thickness. This bevelled ends are needed to be able to make a “Butt weld”. ASME B16.25 covers the preparation of buttwelding ends of piping components to be joined into a piping system by welding. It includes requirements for welding bevels, for external and internal shaping of heavy-wall components, and for preparation of internal ends (including dimensions and dimensional tolerances). These weld edge preparation requirements are also incorporated into the ASME standards (e.g., B16.9, B16.5, B16.34). • MATERIAL AND PERFORMANCE The most common materials used in fittings produced is carbon steel, stainless steel, cast iron, aluminium, copper, the various types of plastics, et cetera et cetera. In addition, fittings, like pipes, for specific purposes sometimes internally equipped with layers of materials of a completely different quality as the fitting themselves, which are “lined fittings”. The material of a fitting is basically set during the choice of the pipe, in most cases, a fitting is of the same material as the pipe.

BUTT WELD FITTINGS: ELBOWS 45°-180° LR/SR The function of a elbow is to change direction or flow in a piping system. By default, there are 5 opportunities, the 45° elbows, 90° elbows and 180° elbows, all three in the “long radius” version, and in addition the 90° elbows  and 180° elbows both in the “short radius” version. • LONG and SHORT RADIUS Elbows are split into two groups which define the distance over which they change direction; the center line of one end to the opposite face. This is known as the “center to face” distance and is equivalent to the radius through which the elbow is bent. The center to face distance for a “long” radius elbow, abbreviated LR always is “1½ x Nominal Pipe Size (NPS) (1½D)”, while the center to face distance for a “short” radius elbow, abbreviated SR even is to nominal pipe size. Here below, for example, you will find the center to face distance of four 2 inch elbows, (the “A” distance on the image). 1. 90° Elbow- 2″- LR : = 1½ x (25,4 x 2)   A = 76,2 mm 2. 180° Elbow– 2″- LR : = 1½ x (25,4 x 2) x 2   A = 152,4 mm 3. 90° Elbow- 2″- SR : = 25,4 x 2   A = 50,8 mm 4. 180° Elbow- 2″- SR : = (25,4 x 2) x 2   A = 101,6 mm • 45º  ELBOW The function of a 45° elbow is the same as a 90° elbow, but the measurement of dimensions is different to that of the 90° elbow. The radius of a 45° elbow is the same as the radius of the 90° LR (1½D). However, the center to face dimension is not equivalent to the radius as in 90° LR elbows. This is measured from each face to the point of intersection of the center lines perpendicular to each other, distances B on the image. This is due to the smaller degree of bend. Short radius 45° elbows are not available. • STANDARDS The most applied version is the 90° long radius elbow and the 45° elbow , while the 90° short radius elbowis 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. In addition to the defined elbows, there is the Reducing Elbow, which is a elbow with various diameters on the ends. Because this elbow, for many suppliers it is not a standard item, and thus probably a high price with a long delivery time, the use of a “normal” elbow with a separate reducer is an option if the situation allows. Other degrees elbows can be machined from a standard elbow. Longer radius type, the center to face dimension e.g. is three times the nominal size (3D), even is available. Dimensions, dimensional tolerances et cetera for long and short radius elbows are defined in ASME B16.9. • WALL THICKNESS The weakest point on an elbow is the inside radius. ASME B16.9 only standardizes the center to face dimensions and some “squareness” dimensional tolerances. The wall thickness at the weld line location even is standardized, but not through the rest of an elbow. The standard states that the minimum tolerance will be within 12.5% of the minimum ordered wall thickness of the pipe. A maximum tolerance is specified only at the ends of the fitting. Many providers of buttweld elbows (and tees) provide one schedule greater thickness so that sufficient wall thickness, after forming, remains.

Pipe fittings are necessary to join together pipes, or to change the direction of an existing pipe. Pipes and pipe fittings are made of a variety of materials, depending on the fluid or gas being transported. Most pipe fittings tend to be threaded to the pipes they connect. Whether you are using steel pipes or PVC pipes, a chemical solvent is required to create a seal between the pipe and the fittings. —Instructions • 1. Measure the required length of the pipe to be installed, keeping in the mind the extra length required where the pipe will be inserted into the fitting. Mark this length on the pipe. • 2. Cut the pipe to the desired length with a hacksaw. If it is a metal pipe, it will be easier to use a reciprocating saw or a grinder. Smooth the cut ends of the pipe with a utility knife if the pipe is made out of plastic, or with a grinder if it is metal. • 3. Insert the pipe into the fittings as a dry fit to confirm that it is the correct size. Remove the pipe from the fittings. • 4. Apply a chemical cement that is appropriate for the type of piping material. Spread it on the inside of the fitting and the outside of the pipe. • 5. Slide the pipe into the fitting until it is fully inserted. Twist it a quarter turn to spread the cement and ensure it is snugly fitted. • 6. Hold onto the pipe and fitting for 60 seconds to ensure the cement dries. Wipe away the excess cement with a damp rag. —Tips & Warnings • Wear gloves to avoid getting the chemical cement onto your skin.

1. Socket Weld Full-Coupling Termed full Coupling, joins pipe two pipe or to a nipple et cetera. 2. Socket Weld Half-Coupling The Half Coupling can be directly welded to the run pipe, to make a branch connection. 3. Socket Weld Reducing Coupling Joints two different outside diameters of pipe. 4. Socket Weld Reducer Insert Socket Weld Reducer Inserts are manufactured to MSS SP-79. They enable quick and economic combinations of pipeline reductions to be made using standard socket weld fittings. 5. Socket Weld Union (MSS SP-83) Unions are primarily used for maintenance and installation purposes. 6. 90° Socket Weld Elbow This 90° Socket Weld Elbows make 90° changes of direction in the run of pipe. 7. 45° Socket Weld Elbow This 45° Socket Weld Elbows make 45° changes of direction in the run of pipe. 8. Lateral Tee This Lateral Tee makes 90° branch from the main run of pipe. 9. Socket Weld Cross SW Crosses makes 90° branch from the main run of pipe. 10. Socket Weld Cap (End Cap) Seals the end of pipe.

Carbon steel pipe fittings, as the name implies, are made of an alloy of carbon and steel. It is forged or cast in a way that there are no seams to weaken the pipe. You must use fittings such as a variety of flanges or butt weld fittings where necessary. These fittings must also be made of carbon steel. •  Small Pipe Fittings Carbon steel pipe that has an interior diameter of less than 2 1/2 inches is usually threaded and joined with a carbon steel union of the same size with the same thread configuration. You will also find other carbon steel fittings such as threaded elbows, both at 45 degrees and 90 degrees. Caps are available if you need to shut off a line. Flangesand double release unions can help in awkward places in gas lines. There are also threaded reductions, such as 2 inch to 1 1/2 inch, or 1 inch to 3/4 inch, made of carbon steel. •  Fittings for Large Pipe Large industrial carbon steel usually has welded unions. One of the exceptions is when the pipe has some type of liner to help prevent corrosion. These liners are usually made of plastic or fiberglass products and can be damaged by the heat of welding. Large carbon steel flanges are available for applications with lined pipe. They also use carbon steel nuts and bolts which can be up to 1 inch in diameter. While these are more expensive to install than a simple weld, they radically reduce corrosion at joins. •  Specialty Fittings You can buy T joins, both with threads, as well as flanges in carbon steel. These, as well as most other fittings, come in a variety of carbon steel alloys. Lap joins and slip on joins are also available for carbon steel pipe up to 4 inches in diameter. These fittings are used on carbon steel pipe used for everything from household gas lines to the transportation of toxic liquids in an industrial setting.

The butt weld and the socket weld are two different ways to weld two pieces of materials together. •  Butt Weld A butt weld is two pieces of materials butted against each other and welded. Several different methods exist for beveling the two pieces for good weld penetration. Both flat stock and pipe or tubing can be butt welded. Generally, the weld is ground flush with the material surface. • Socket Weld A socket weld involves two different sized pieces of pipe. The smaller one is inside the larger pipe. The weld is completely around the outside circumference of the larger pipe.

A ANSI: American National Standards. A piping specification. ASME: American Society of Mechanical Engineers. A piping specification. ASTM: American Society for Testing Materials. A piping specification. Ambient Temperature: The average temperature of the atmosphere in the area of an appliance. B BSP: British Standard Piping. A piping specification. Bushing: A pipe fitting, threaded on both the inside and outside, used for joining pipes with different diameters together. C Coupling: A fitting that joins two pieces of pipe. Cast Iron: Metal formed by casting in molds. Cross: Used for 4-way branch connections. E Elbows: Change direction of pipe. F Female thread: Threaded on the outside. Flange: A type of pipe fitting that connects via nuts and bolts. H Hex plug: The hex pipe plug is threaded in the end and the top of the plug takes a hexagon shape. I I.D.: Inside diameter. All pipes are sized according to their inside diameter. L Lap joint flange: Flanges are used on piping fitted with lapped pipe or with lap joint stub ends. M Male thread: Threaded on the inside. N Nipple: A length of straight pipe with male threads on both ends. O O.D.: Outside diameter. All pipes are sized according to their outside diameter. Orifice flange: Flanges where orifice plate or flow nozzle is used. P Pipe fittings: Available in various shapes, sizes and materials, they are used to connect pipes. Plug: Cap end inserted into the end of tubing to dead-end the flow. R Reducer: A fitting that connects pipes of different sizes. T Tee: A T-shaped pipe fitting with three openings used to create branch lines. U Union: Three-piece fitting that joins two sections of pipe and they also can be disconnected without cutting the pipe. W Wye: A Y-shaped fitting with three openings used to create branch lines.

Pipe fittings are an essential element of industrial and residential plumbing. Pipe fittings connect sections of pipes and ensure the proper installation of pipeline systems. Fittings can connect straight sections of pipes, change the direction of pipes or the end of a pipe. There are thousands of specialized pipe fittings available to meet the requirements of various pipe types, materials and applications; but most fittings share some common characteristics. • Pipe Fittings Materials Pipe fittings should always be made of the same material as the pipes being connected. Pipes are manufactured from a variety of materials such as copper, aluminum, steel and iron. Some types of pipes are better suited to certain applications than others. Pipe fittings should always be made of the same material as the pipes being connected. • Elbows Elbows are pipe fittings that change the direction of a pipe. Elbows are typically manufactured with a 45-degree or 90-degree elbow, but custom elbow fittings are also available. Commonly used in industrial or pressurized applications, the connectors of an elbow fitting may be either threaded or machined for welding. Elbow fittings with one end smaller than the other function as reducers, connecting pipes of different sizes. • Reducers Reducers connect pipes of different sizes. They are available in concentric or eccentric. One connecting end of the reducer is larger than the other. Pipe reducers often have male threads on one end and female threads on the other. Reducers come in a wide variety of materials, sizes and types, designed to suit specific applications. • Tee fittings Tee fittings connect three sections of pipe. The tee fitting has one connection at 90 degrees to the other two connections. Used to connect pipelines running at right angles to each other, the tee fitting has three female connections. The tee fitting is also available in a reducing version with two openings the same size and one opening a different size. • Cross fittings Cross fittings are used to combine or split pipe or tube sections. Cross fittings have one input and three outputs (or vice versa) that intersect at 90 degree angles. All three designs come in standard designs (in which all outlets/inlets are the same diameter) and reducing designs (in which one or more is a different size). • Couplings/ Unions Couplings and unions are pipe fittings used to extend the run of a pipe section by connecting it with another section. A coupling is a more permanent connection using soldering, solvent welding. A union is a nut with a male and female end that screw into corresponding pipe sections. The union allows pipes to be disconnected quickly and easily • Caps and Plugs Caps and plugs perform basically the same function but in different ways. A cap, as its name suggests, is a cap that goes over the end of a pipe, creating a dead end. Plugs also stop up a pipe or tube system, but are plugged, like a stopper, into the end of the pipe.

Pipe welding is performed to join two metal parts of a pipe, like the pipe itself and the fitting, together to prevent leakage. The fitting is a part that comes in various sizes and designs, and it is specifically used to join two or more pipes together. The fitting may also be used to make bends in the pipe line where necessary. • Plug Fittings The plug fitting is used to cap off an end of pipe that would otherwise spill out the material held by the pipe. The plug is placed on the pipe with a socket wrench, which is dependent on the type of fastening hole on top of the plug used. Of the numerous designs, there are hexagon head plug, square head plug, round head plug. • Pipe Union Pipe union fittings are meant to screw onto, and seal, a pipe without requiring a weld. Unionsmay be male to male, female to male or female to female. With a female end, the outside of the fitting is smooth, while threads line the inside. The male end would be the opposite, with threads on the outside. • Pipe Elbows An elbow is a short pipe piece at a 90° angle. The elbow is used to create a turn in the pipes, where an obstruction is able to be moved. The elbow comes in a variety of sizes, including one end being larger than the other to gradually reduce the pipe diameter overall. • Pipe Tees A tee is used to join together three separate pipes. The part looks just like a T, with two ends set in a horizontal fashion and the third end directly in the center, running vertical. • Pipe Welding Aside from the threaded fittings available, there are many types of connections that require welding two smooth surfaces together, like most elbows or tees. The procedure cannot take place until the area is entirely clean. There cannot be dripping water or other material in the pipe while it is being welded. The metal is typically preheated to soften the ends of the pipe and fitting, then the fitting is set into place. Once the piece is in place, the final weld is made. The binding metal, with a melting point of higher than 450° Celsius but less than the melting point of the pipe metal, is held over the fitting and heated until it melts into the cracks. Once the weld is secure, the pipes are checked for leaks, then welded once more if needed.