Grooved Segmented Ring Coupling and Flange Joints on Pipe Systems

Huff.... I felt so boring today, may be because I'm to tired, but for Piping & Fabrication I will keep posting, and we reach to the explanation of Grooved Segmented Ring Coupling and Flange Joints. I hope this will make us more understand about piping systems because now I want to take a rest for a while.

Grooved Segmented-Ring Coupling
The type of split coupling shown in Fig. A2.34 is used with either ductile cast-iron or steel pipe that has grooves near the ends which enable the coupling to grip the pipe, in order to prevent disengagement of the joint. The couplings are manufactured in a minimum of two segments for small pipe sizes and several segments for large pipe sizes. Grooved-end fittings are available for use with the couplings. With proper choice of gasket material, the joint is suitable for use above- or underground with nearly any fluid or gas. The joint’s advantages are its

FIGURE A2.34 Victualic coupling for grooved end cast iron steel pipe

FIGURE A2.35 Screwed-on cast-iron flange

FIGURE A2.36 High-hub cast-iron flanges with bitumastic
to protect the exposed threads

•    Ability to absorb minor angular and axial deflections
•    Ability to increase gasket sealing force with increased system pressure
Refer to AWWA C.606, Standard for Grooved and Shouldered Joints.
•    Simplicity for rapid erection or dismantling for systems requiring frequent disassembly.
The coupling is also available in a style where grooving of the pipe ends is not required. Joint separation is prevented by the use of hardened steel inserts (teeth) which grab the mating pipe ends.

TABLE A2.25 Standard Dimensions of Class 125 Flanged Joints for Silver Brazing with
Centrifugally Cast Pipe

Flanged Joints
Flanged ductile or cast-iron pipe is used aboveground for low and intermediate pressures in water-pumping stations, gas works, power and industrial plants, oil refineries, booster stations for water, and gas and oil transmission lines. Cast iron flanges usually are faced and drilled according to ASME B16.1. For flanged joints in a ductile iron pipe, refer to ASME B16.42, ANSI/AWWA C110/A21.10, C111/A21.11, C115/A21.15, and C153/A21.53. Cast-iron pipe is made both with integrally cast flanges and with threaded companion flanges for screwing onto the pipe (as shown in Figs. A2.35 and A2.36). In the latter case, the outside diameter of the pipe conforms to iron pipe size (IPS) dimensions to allow for the threads provided. It is available in sizes NPS 3 (DN 50) through NPS 24 (DN 600) and in length to 18 ft (5.5 m). For lengths less than 3 ft (1 m), in sizes NPS 3 (DN 50) through NPS 12 (DN 300), the flanges may be cast integrally with the pipe, rather than screwed on the pipe, at the manufacturer’s option. Standard dimensions of flanged joints for silver brazing are shown in Table A2.25.

Know More about Backing Rings on Piping Systems

The Blogger has unavailable status yesterday, so Piping & Fabrication can not continue the post for this blog, but now I will continue and now we will Know More about Backing Rings on Piping Systems.

backing rings

Backing rings are employed in some piping systems, particularly where pipe joints are welded primarily by the shielded metal-arc welding process with covered electrodes. For example, a significant number of pipe welds for steam power plants and several other applications are made with the use of backing rings. On the other hand, in many applications backing rings are not used, since they may restrict flow, provide crevices for the entrapment of corrosive substances, enhance susceptibility to stress corrosion cracking, or introduce still other objectionable features. Thus, there is little, if any, use made of backing rings in most refinery piping, radioactive service piping, or chemical process piping. The use of backing rings is primarily confined to carbon and low-alloy steel and aluminum piping. Carbon-steel backing rings are generally made of a mild carbon steel with a maximum carbon content of 0.20 percent and a maximum sulfur content of 0.05 percent. The latter requirement is especially important since high sulfur in deposited weld metal (which could be created by an excessive sulfur content in such rings) may cause weld cracks. Split backing rings are satisfactory for service piping systems. For the more critical service applications involving carbon- and low-alloy steel piping, solid flat or taper-machined backing rings are preferred in accordance with the recommendations shown in Pipe Fabrication Institute Standard ES1 and illustrated in Fig. A2.24 and Table A2.21.

When a machined backing ring is desired, it is a general recommendation that welding ends be machined on the inside diameter in accordance with the Pipe Fabrication Institute standard for the most critical services and then only when pierced seamless pipe that complies with the applicable specifications of the American Society for Testing and Materials is used. Such critical services include high pressure steam lines between boiler and turbines and high-pressure boiler feed discharge lines, as encountered in modern steam power plants. It is also recommended that the material of the backing ring be compatible with the chemical composition of the pipe, valve, fitting, or flange with which it is to be used. Where materials of dissimilar composition are being joined, the composition of the backing ring may be that of the lower alloy.
On turned-and-bored and fusion-welded pipe, the design of the backing ring and internal machining, if any, should be a matter of agreement between the customer and the fabricator. Regardless of the type of backing rings used, it is recommended that the general contour of the welding bevel shown in Fig. A2.24 be maintained.
When machining piping for backing rings, the resulting wall thickness should be not less than that required for the service pressure. Wherever internal machining for machined backing rings is required on pipe and welding fittings in smaller sizes and lower schedule numbers than those listed in Table A2.21, weld metal may have to be deposited on the inside of the pipe in the area to be machined. This is to provide satisfactory contact between the machined surface on the pipe inside and the machined backing ring. For such cases, the machining dimension should be a matter of agreement between the fabricator and the purchaser.

Whenever pipe and welding fittings in the sizes and schedule numbers listed in Table A2.21 have plus tolerance on the outside diameter, it also may be necessary to deposit weld metal on the inside of the pipe or welding fitting in the area to be machined. In such cases, sufficient weld metal should be deposited to result in an ID not greater than the nominal ID given in Table A2.21 for the particular pipe size and wall thickness involved.

Experience indicates that machining to dimension C for the pipe size and schedule number listed in Table A2.21 generally will result in a satisfactory seat contact of 7/32 in (5.5 mm) minimum (approximately 75 percent minimum length of contact) between pipe and the 10_ backing ring. Occasionally, however, it will be necessary to deposit weld metal on the inside diameter of the pipe or welding fitting in order to provide sufficient material for machining a satisfactory seat. In welding butt joints with backing rings, care should be exercised to ensure good fusion of the first weld pass into the backing ring in order to avoid lack of weld penetration or other types of stress-raising notches.

Just to remembering you, all this post is connected with the others and you better read those one to, thanks!

Relation of Gaskets to Bolting on Piping Systems

Relation of Gaskets to Bolting. 

gasket

There is a tendency, as indicated in the ASME Rules for Bolted Flanged Connections, to assign lower residual contact-pressure ratios ranging from about 1 for soft-rubber gaskets to 6 or 7 for solid-metal gaskets. Whereas these are said to have proved satisfactory service for heat-exchanger and pressure-vessel flanges, the more severe service encountered by pipe flanges due to bending moments and large temperature changes is considered by many to warrant designing on the basis of the larger residual gasket compression ratios recommended in the previous paragraph. The lack of understanding of the mechanics of gasket action, the variety of gasket materials, shapes, widths, and thicknesses; the variety of facings used; the variation in flange stiffness; and the uncertainties in bolt pull-up are among the factors that render difficult a precise solution to the problem of gasket design.

Rules for bolting and flange design are contained in Sections III and VIII of the ASME Boiler and Pressure Vessel Code.

The parts of Gasket now finish for a moment, and in the next post we will continue with Bolting, and still with Piping & Fabrication, and hope everything will be useful to us.

GASKET ON PIPE SYSTEMS

Getting deeper and deeper with Pipe Systems and everything connected with it and with Piping & Fabrication we will keep explore everything about Piping, Fabrication, Structure, Construction, Welding, etc. And now we will talk about Gasket on Pipe Systems.

Since it is expensive to grind and lap joint faces to obtain fluid-tight joints, a gasket of some softer material is usually inserted between contact faces. Tightening the bolts causes the gasket material to flow into the minor machining imperfections, resulting in a fluid-tight seal. A considerable variety of gasket types are in common use. Soft gaskets, such as cork, rubber, vegetable fiber, graphite, or asbestos, are usually plain with a relatively smooth surface. The semi metallic design combines metal and a soft material, the metal to withstand the pressure, temperature, and attack of the confined fluid and the soft material to impart resilience. Various designs involving corrugations, strip-on-edge, metal jackets, etc., are available. In addition to the plain, solid, and flat-surface metal gaskets, various modified designs and cross-sectional shapes of the profile, corrugated, serrated, and other types are used. The object in general has been to retain the advantage of the metal gasket but to reduce the contact area to secure a seal without excessive bolting load. Effective gasket widths are given in various sections of the ASME Boiler and Pressure Vessel Code.

TABLE A2.19 Selections of Gasket Materials for Different Services

Gasket Materials. 

Gasket materials are selected for their chemical and pressure resistance to the fluid in the pipe and their resistance to deterioration by temperature. Gasket materials may be either metallic or nonmetallic. Metallic ring-joint gasket materials are covered by ASME Standard B16.20,

Steam Traps, Float, Thermostatic, Thermodynamic, Inverted Bucket on Pipe System

After fix the computer because of data corrupt, so I have to installed the new one. And now Piping & Fabrication ready to continue.

TRAPS
Steam Traps

The function of a steam trap is to discharge condensate from steam piping or steam heating equipment without permitting live steam to escape. Some principal types of steam traps are:

• Float
• Thermostatic
• Thermodynamic
• Inverted bucket

FIGURE A2.5 Float steam trap

trap strainer unit

balanced pressure thermostatic trap

The float type (Fig. A2.5) consists of a chamber containing a float-and-arm mechanism which modulates the position of a discharge valve. As the level of condensate in the trap rises, the valve is opened to emit the condensate. This type of valve tends to discharge a steady stream of liquid since the valve position is proportional to the rate of incoming condensate. Because the discharge valve is below the waterline, float-type steam traps must employ a venting system to discharge noncondensable gases. This is generally accomplished with a thermostatic element which opens a valve when cooler noncondensable gases are present but closes the valve in the presence of hotter steam. The thermostatic steam trap (Fig. A2.6) contains a thermostatic element which opens and closes a valve in response to fluid temperature. Condensate collected upstream of the valve is subcooled, cooling the thermostat, which, in turn, exposes the discharge port. When the cooler condensate is discharged and the incoming condensate temperature approaches the saturation temperature, the thermostat closes the discharge port. Because of its principle of operations, the thermostatic trap operates intermittently under all but maximum condensate loads.

The inverted bucket steam trap (Fig. A2.7)

Forged Branch Fittings of Piping

Continuing from the last chapter yesterday, now the Table of Piping Fundamental base on ASME will be more and more and still with Piping & Fabrication.

 

TABLE A2.13 Dimensions of Typical Commercial Straight Butt-Welding Tees

Forged Branch Fittings
Under the various pressure piping codes, branch connections may be made by welding the branch pipe or a welding outlet fitting to the run pipe, provided sufficient reinforcement is available to compensate for the material removed from the run pipe to create the branch opening. The reinforcement may be in the form of excess material already available in the run and branch pipes, or it may be added. At the writing of this book, national standards governing the dimensions, tolerances, and manufacture of welding outlet fittings had not been issued. However, MSS-SP-97, 1995, has been developed to cover forged-carbon-steel 90° branch outlet fittings in butt-welding, socket-welding, and threaded outlet ends. The standard provides essential dimensions, finish, tolerances, and testing requirements.

Wrought Steel Butt Welding Fitting full with the ASME table

For few posting in the next post that would be a lot of table will comes according with ASME and now Piping & Fabrication will continue with Wrought Steel Butt Welding Fitting full with the table.

Wrought-Steel Butt-Welding Fittings
Wrought-steel welding fittings include elbows, tees, crosses, reducers, laterals, lap joint stub ends, caps, and saddles. Wrought-steel fittings are made to the dimensional requirements of ASME B16.9 in sizes NPS 1⁄₂ (DN 15) through NPS 48 (DN 1200). Also, short-radius elbows and returns are produced in accordance with ASME B16.28 in sizes NPS 1⁄₂ (DN 15) through NPS 24 (DN 600). The wrought fitting materials conform to ASTM A234, A403, or A420, the grades of which have chemical and physical properties equivalent to that of the mating pipe. ASME B16.9 requires that the pressure-temperature rating of the fitting equal or exceed that of the mating pipe of the same or equivalent material, same size, and same nominal wall thickness. The pressure-temperature rating may be established by analysis or by proof testing. Short-radius elbows and returns (fitting centerline bend radius is equal to the fitting NPS) manufactured under ASME B16.28 are rated at 80 percent of the rating calculated for seamless straight pipe of the same size and nominal thickness and same or equivalent material.
Therefore, both standards require that, in lieu of specifying any pressure rating, the pipe wall thickness and pipe material type with which the fittings are intended to be used be identified on the fitting. Pressure testing of the fittings is not required by either standard. However, the fittings are required to be capable of withstanding, without leakage, a test pressure equal to that prescribed in the specification of the pipe with which the fitting is recommended to be used. Both ASME B16.9 and B16.28 prescribe dimensions and manufacturing tolerances of wrought butt-welded fittings. The standards establish laying dimensions, which remain fixed for each size and type of fitting irrespective of the fitting wall thickness. Tables A2.11, A2.12, A2.13, A2.14, and A2.15 list the laying dimensions and approximate weights for selected fitting sizes, pipe schedules, and configurations. 

TABLE A2.11 Dimensions of Typical Commercial 90 degree Long-Radius Butt-Welding Elbows

Laterals are not governed by any national standard. However,

Internal Threads of Threaded Fittings

I should post this with the last post, but I don't have enough times to do it, because I have to finish the job first, and now Piping & Fabrication will continue the last article about Threaded Fittings.

Threaded fittings are available in pressure Classes 2000, 3000, and 6000. Socket welded fittings are available in pressure Classes 3000, 6000, and 9000. Limitations on fitting size and service conditions are as provided for by the code governing the installation. The maximum allowable pressure of the fitting is equal to that computed for straight seamless pipe of equivalent material, considering manufacturing tolerance, corrosion allowance, and mechanical strength allowance. Also, for socket welding fittings, the pressure rating must be matched to the pipe wall thickness to ensure that the flat of the band can accommodate the size of the fillet weld required by the applicable code. The recommended fitting pressure class for the various pipe wall thicknesses is as follows:

Internal threads of threaded fittings are in accordance with ASME B1.20.1-Pipe Threads, General Purpose (Inch).

Cast Forged Steel, Nickel Alloy Flanged Fittings and Forged Steel Threaded, Socket Welding Fittings

After fix the computer for a while and use the internet connection from the office, now Piping & Fabrication will start to post again.

Cast and Forged Steel and Nickel-Alloy Flanged Fittings
Flanged fittings of steel and nickel alloys are manufactured in accordance with ASME B16.5. The standard covers ratings, materials, dimensions, tolerances, marking, testing, and methods of designating openings for pipe flanges and flanged fittings in sizes NPS 1⁄₂ (DN 15) through NPS 24 (DN 600) and in rating Classes 150, 300, 400, 600, 900, 1500, and 2500. However, not all sizes are available in all pressure classes. Dimensions of more commonly used fittings are given in Table A2.7. The standard also contains recommendations and requirements for bolting and gaskets. Within each pressure class, the dimensions of the fittings are held constant, irrespective of the materials being used. Since the physical properties of different materials vary, the pressure-temperature ratings within each pressure class vary with the material. As an example, a Class 600 forged carbon steel (A105) flange is rated at 1270 psig at 400_F, whereas a Class 600 forged stainless steel (A182, F304) flange is rated at 940 psig at 400_F. The matrix of materials and pressure classes is too numerous to reproduce here; therefore, the reader is referred to ASME B16.5 for the flanged fitting pressure-temperature ratings. Figures A2.1, A2.2, and A2.3 illustrate the reduction in pressure rating with increase in temperature for group 1.1 (ASTM A105), 1.10 (ASTM A182, Gr. F22, Cl. 3), and 2.1 (ASTM A182, Gr. F304) materials.

Forged Steel Threaded and Socket Welding Fittings
Forged-steel socket welding and threaded fittings are manufactured in accordance with

Soldered Joint Fittings and Cast Iron Flanged Fittings

Soldered-Joint Fittings

TABLE A2.5 Pressure Ratings for Solder Joints (ASME B16.18-1984). Maximum Working Pressure (psi).

Soldered-joint wrought metal and cast-brass or -bronze fittings for use with copper water tubes are covered by ASTM B88 and H23.1. The fittings are made in accordance with ASME B16.22 and B16.18, respectively. Joints using these types of fittings and made with 50–50 tin-lead solder, 95-tin 5-antimony solder, or solder melting above 1100_F (593_C) have the pressure-temperature ratings shown in Table
A2.5. (Note: Lead-bearing solder is not permitted for potable water service.) Wrought copper fittings normally have a minimum copper content of 83 percent. Cast-brass fittings conform to ASTM B62 and have a nominal composition of 85 percent copper, 5 percent tin, 5 percent lead, and 5 percent zinc. The minimum requirements for 50–50 tin-lead solder generally used with these fittings are covered in ASTM B32 alloy grade 50A. Metal thickness tolerances and general dimensions of fittings are given in ASME B16.18.

Cast-Iron Flanged Fittings

Cast-iron flanged fittings are produced in accordance with ASME B16.1.

Ductile and Cast-Iron Fittings of Piping Fundamentals

Let us entering the Ductile and Cast Iron Fittings which covered by number of ASME standards, only on Piping & Fabrication.

Ductile and Cast-Iron Fittings
Cast-iron fittings are covered by a number of ASME and ANSI/AWWA standards:
ASME B16.1
Cast Iron Pipe Flanges and Flanged Fittings, Class 25, 125, 250, and 800 (The standard also includes bolt, nut, and gasket data.)

ASME B16.
4 Gray Iron Threaded Fittings, Class 125 and 250
ASME B16.12
Cast Iron Threaded Drainage Fittings
ANSI/AWWA C110/A21.10
Ductile Iron and Gray Iron Fittings, 3-in through 48-in (76 mm through 6200 mm), for Water and Other Liquids
ANSI/AWWA C115/A21.15
Ductile Iron and Gray Iron Fittings, 3-in through 48-in (76 mm through 1200 mm), for Water
ANSI/AWWA C153/A21.53
Ductile Iron Compact Fittings, 3-in through 24-in (76 mm through 610 mm) and 54-in through 64-in (1400 mm through 1600 mm), for Water Service

Cast-Iron Threaded Fittings
Cast-iron threaded fittings are covered by ASME Standard B16.4. The standard specifies the below-listed attributes for Class 125 and Class 250 tees, crosses, 45_and 90_ elbows, reducing tees, caps, couplings, and reducing couplings in sizes ranging from NPS 1⁄₄ (DN 6) through NPS 12 (DN 300), inclusive. However, in Class 250, the standard only covers 45_ and 90_ elbows, straight tees, and straight crosses.

HEAT AND TEMPERATURE OF PIPE

Units of Heat.
The unit of heat commonly used in the English system is the British thermal unit, or Btu, and is approximately equal to the quantity of heat that must be transferred to one pound of water in order that its temperature be raised one degree Fahrenheit. In laboratory work and throughout much of the world, the calorie is the common unit of heat. A gram calorie is the approximate quantity of heat that must be transferred to 1 gram (g) of water in order to raise its temperature by 1*C. The kilocalorie, sometimes called the kilogram calorie, is equal to 1000 gram calories.

Now with Piping and Fabrication, we will go deeper and deeper! and with Heat and Temperature of Pipe continue.

The definitions above are indicated as being approximate because, over the temperature range from freezing to boiling points of water, different quantities of heat are required to produce a unit temperature change. For this reason, the calorie and the Btu have been defined in international units as

In most engineering work, it is sufficiently accurate to use 1 kg . cal = 3.968 Btu and 1 Btu = 0.252 kg . cal.

Units of Temperature.
The relative ‘‘hotness’’ or ‘‘coldness’’ of a body is denoted by the term temperature. The temperature of a substance is measured by noting its effect upon a thermometer or pyrometer whose thermal properties are known. The mercury thermometer is suitable for measuring temperatures from _39 to about 600_F. This limit may be extended to 1000_F if the capillary tube above the mercury is filled with nitrogen or carbon dioxide under pressure. High temperatures must be measured with thermocouples or optical pyrometers. The most commonly used thermometer scales are the Fahrenheit and the Celsius. Thermometer scales have as their bases the melting and boiling points of water, both measured at atmospheric pressure. The relation of the Fahrenheit and Celsius scales is as follows:

The relation between the two scales is

in which C is the reading on the Celsius scale and F is the reading on the Fahrenheit scale.

In certain calculations,

Piping Fundamental as The Important Pipe Elements

Starting today, Piping & Fabrication will start the new chapter of this pipe handbook, and now we go to PIPING FUNDAMENTAL as the important pipe elements.

FORCES, MOMENTS, AND EQUILIBRIUM
Simple Forces. When two or more forces act upon a body at one point, they may be single or combined into a resultant force. Conversely, any force may be resolved into component forces. In the figure, let the vectors F1 and F2 represent two forces acting on a point O. The resultant force F is represented in direction and magnitude by the diagonal of the parallelogram of which F1 and F2 are the sides. Conversely, any force F may be resolved into component forces by a reverse of the above operation.

vector and moments

Moments.
The moment of a force with respect to a given point is the tendency of that force to produce rotation around it. The magnitude of the moment is represented by the product of the force and the perpendicular distance from its line of action to the point or center of moment. In the English system of weights and measures, moments are expressed as the product of the force in pounds and the length of the moment arm in feet or inches, the unit of the moment being termed the pound-foot or the pound-inch. Moments acting in a clockwise direction are designated as positive, and those acting in a counterclockwise direction are negative. They may be added and subtracted algebraically, as moments, regardless of the direction of the forces themselves.

 

With respect of that figures, moments about an arbitrary point x are calculated as follows: Extend the line of action of F1 until its extension intersects the perpendicular ax drawn from point x. Draw bx from x perpendicular to F2. The sum of moments about point x due to the two forces is then Alternatively, since F1 and F2 have been shown to be the vector equivalent of the resultant F, the moments about x can be calculated as

Couples.
Two parallel forces of equal magnitude acting in opposite directions constitute a couple. The moment of the couple is the product of one of the forces and the perpendicular distance between the two. A couple has no single resultant and can be balanced only by another couple of equal moment of opposite sign.

Law of Equilibrium.
When a body is at rest, the external forces acting upon it must be in equilibrium and there must be a zero net moment on the body. This means that (1) the algebraic sums of the components of all forces with reference to any three axes of reference at right angles with one another must each be zero and (2) the algebraic sum of all moments with reference to any three such axes must be zero. When the forces all lie in the same plane, the algebraic sums of their components with respect to any two axes must be equal to zero and the algebraic sum of all moments with respect to any point in the plane must be zero.

stay tune in Piping and Fabrication, because we will know much about Pipe, Piping, Welding, Fabrics, Fabrication, etc, just to fill this mind with knowledge of pipe system.