.piping

What is a weld cap?

It is a fitting used to seal an open end of pipe.

Pipe Size

The size represented the approximate inside diameter of the pipe in inches. An IPS 6 pipe is one whose inside diameter is approximately 6 inches (in). Users

Types of piping systems

a) PLANT UTILITIES

Types of pipe fittings

1) Elbow a) 90° ELBOWS b) 45° ELBOWS 2) Tee a) Straight-all b) Reducing-branch 3)COUPLING 4) Reducers 5) Weld cap

Piping components include:

1. Pipe 2. Pipe fittings 3. Flanges 4. Gaskets 5. Bolting 6. Valves 7. Specialities 8. Equipment

Piping spool

A spool is an assembly of pipe and associated components that can be pre-fabricated in the workshop for future installation and then shipped to site for assemblin

What does a cooling tower do?

After circulating through equipment such as exchangers and condensers, cooling water will have accumulated substantial heat gain. Without dissipating the heat gain, cooling water will lose its cooling effectiveness. A cooling tower is a mechanical device that will lower the temperature of cooling water. Cooling towers are uniquely designed to dissipate heat gain by evaporating specific amounts of aerated water that has been circulated through an air-induced tower. Although there is a significant amount of drift (the amount of water lost during the aerating and evaporation sequence) cooling towers are extremely efficient and are widely used. Older cooling towers are easily recognizable because they are constructed of wood and have horizontal slats resembling louvers with water cascading down the walls. Figure 6-18 represents a typical cooling tower.

What does an exchanger do?

Another common piece of mechanical equipment is the exchanger. Its purpose in a piping facility is to transfer heat from one commodity to another. Whether the objective is to heat a liquid to a desired temperature or cool a product for final storage, the exchanger can accomplish both. Exchangers do not mix commodities together, but rather transfer heat through contact with a surface of a different temperature. An exchanger most people are familiar with is the common household water heater. Cold water flows around a heated element to warm the water. A number of exchanger types are available; they include the shell and tube, double pipe, reboiler, and air fan.

THE STUB-IN

Another method of making a branch connection is called a stub-in. The stub-in is most commonly used as an alternative to the reducing tee. The stub-in is not an actual fitting but rather a description of how the branch connection is created. A hole is bored into the header pipe, either the size of the OD or ID of the branch, and the branch is then stubbed into it. The two pipes are fitted together and then welded. Although the branch connection can be the same pipe size or smaller as the header, it cannot be larger.

INSTALLATION Leak Testing

At one time, complex shapes were pressure-tested to determine their suitability for the service intended. This involved stressing the component to a point above service stresses, but below bursting stress, and was referred to as a pressure test. Currently most codes require some type of test to determine leak tightness rather than service suitability. The most common method of leak testing for piping systems is the hydrostatic test. Usually this involves water at ambient temperature as the test medium. B31.1 requires that the system be pressurized to 1.5 times the design pressure, ASME III, to 1.25 times the design pressure, and B31.3 requires a test pressure of 1.5 times the design pressure adjusted by the ratio of the allowable stress at test temperature divided by the allowable stress at operating temperature. In each case, however, the test pressure of unisolated equipment or some function of the yield stress of the line material may be a limiting factor. See the applicable code for particulars. The line must be held at test pressure for at least 10 min, but may be reduced as permitted in the applicable code until the examination for leakage is complete.

INSTALLATION BENDING

Bending, if used at all, is limited to small-diameter piping using relatively simple bending equipment at ambient temperatures. Occasionally in order to correct for misalignment, larger-diameter ferritic piping is bent at temperatures below the lower critical. Please note that this procedure is limited to ferritic materials. Any application of heat to austenitic materials will result in sensitization and loss of corrosion properties.

PIPE FABRICATIO OPERATION/FORMING- 2a Bending: economics and limitations

Bending: Economics: The use of bends versus welding fittings for changes in direction should be carefully evaluated from an economic viewpoint. Bends whose radii range from 3 to 5 times the nominal pipe diameter will offer the least pressure drop while still affording adequate flexibility to the system. Since each bend eliminates a welding fitting and at least one weld with its attendant examination, bending is very often the economic choice. In the case of special pipe sizes which are frequently used for main steam, reheat, and feed water lines in large central power generating units, bending may be the only option available. Limitations. The metal being bent should preferably exhibit good ductility and a low rate of strain hardening. Most metals used in piping systems fulfill these requirements. A successful bend is also a function of its diameter, thickness, and bending radius.

What is coupling?

COUPLING Another type of fitting used to make branch connections is the coupling. Used primarily for connecting small-bore screwed and socket-weld pipe to large-bore pipe headers, the coupling is also used extensively where instrument connections are required. There are two common methods used to make branch connections with couplings: 1. The coupling rests on the external surface of the pipe header and is welded from the outside. 2. A hole is bored into the pipe header large enough to accept the OD of the coupling. The coupling is inserted into the hole and is then welded.

describe cages

Cages are designed to enclose a ladder and prevent a worker from falling away should he lose his grip on the rungs. Made of steel plate, cages provide the worker with a sense of security when scaling tall vertical structures

INSTALLATION COLD SPRING

Cold Spring Both the B31.1 and B31.3 Codes address cold springing in detail. Cold spring is the intentional stressing and elastic deformation of the piping system during the erection cycle to permit the system to attain more favorable reactions and stresses in the operating condition.I

What does a CONTROL VALVE MANIFOLDS do?

Control of the commodity traveling through pipe and equipment and accessibility to the controlling apparatus are two major concerns in any piping facility. The control valve manifold addresses both of these concerns. The control valve manifold is a series of valves, fittings, and piping placed at grade or platform level that uses an automatic valve to control and monitor the flow of a commodity through a piping system. The photograph in Figure 12-2 depicts a typical control valve manifold arrangement. Notice the valves used in Figure 12-2. Four different types of valves are used in the typical control valve manifold. The valve in the center of the configuration is the control valve. It has a globe valve or similar body type and uses a pneumatic or hydraulic actuator to automatically regulate the commodity's rate of flow. The valves to the right and left of the control valve are called block valves. Block valves are gate valves that are used to block the flow of the commodity through the control valve during times of repair or replacement. When the block valves are closed, the commodity can be controlled manually by the bypass valve. The bypass valve is either a globe, plug, or ball valve located on the bypass line found above the control valve. The bypass valve is normally closed but is opened when the block valves are closed and flow must be regulated manually. The fourth valve type is the drain valve. It is the small valve shown below the left reducer. The drain valve is opened after the block valves have been closed and before the bolts have been loosened on the flanges that sandwich the control valve. The drain allow the commodity trapped below the two block valves to be captured and disposed of without a spill occurring.

INSTALLATION Tubing

Copper, aluminum, steel, and stainless-steel tubing are frequently used in hydraulic, pneumatic, and sampling systems. Installation is most often concerned with protection of such materials from damage, since they are often associated with control systems. The manner of protection is left to the designer's judgment. Lighter wall tubing is often bent using small compression-type benders. Tubing is joined to itself and to pipe-size fitting and components with a variety of proprietary tubing fittings which are described in Chap. A2. Some heavier-wall stainless-steel tubing is welded using specially designed socket welding fittings. GTAW welding with filler metal added is used for such applications.

Piping FABRICATION PROCESS-1: Cutting and Beveling:

Cutting and Beveling. The methods of cutting plate or pipe to length can be classed as mechanical or thermal. Mechanical methods involve the use of saws, abrasive discs, lathes, and pipecutting machines or tools. Thermal methods are oxyfuel gas cutting or electric arc cutting. Weld end bevels can also be prepared by the mechanical or thermal methods just described. Both mechanical and thermal methods are used to apply the V bevel, which is used in the vast majority of piping applications. For compound and U bevels or those which may involve a counterboring requirement, horizontal boring mills are most appropriate. Various factors to be considered in selecting a weld end bevel are discussed in the section, ''Welding Joint Design.''

What are shop drawings

Detailed construction and fabrication drawings that show the proposed material, shape, size, and assembly of the parts and how the entire unit will be installed.

What's a meter run

Developing a piping system that incorporates smooth and consistent flow characteristics is imperative in any piping facility. The ability to measure the rate of flow of a commodity is necessary at various stages throughout a facility. Rate of flow is simply a measurement of the amount of commodity flowing through a pipe in a specified amount of time. The most common way to achieve this is through a section of pipe referred to as a meter run. A meter run is the name given to a straight run of pipe that uses a set of orifice flanges to measure the rate of flow. You may recall, orifice flanges have valve taps that allow monitoring equipment to be attached to record the differential pressure of a commodity traveling through an orifice plate (see Figure 12-7).

FABRICATION Steps

Drawings installation Drawings shop detail drawings

Types of elbows

Elbows can turn up, turn down, turn left, right, or any angle in between. Ninety degree ells can be classified as one of the following: • long-radius ell • short-radius ell • reducing ell • mitered ell 90° ELBOWS 45° ELBOWS

INSTALLATION FIELD POST WELD HEAT TREATMENT

Field postweld heat treatment also follows the practices outlined in the section ''Heat Treatment'' for local stress-relieving of ferritic materials. This usually involves induction or resistance heating units with recording devices. For small pipe welds, torch heating using temperature-sensitive crayons to control temperature is sometimes used. Exothermic heating to stress-relieve welds is still used on occasion for outdoor applications where heating rates are not required to be controlled.

INSTALLATION WELDING

Field welding is more often than not in a fixed position. Welders should be qualified in the 6G position since this qualifies for all positions. Welding will be done using SMAW,GMAW,FCAW,and GTAW. Some welding processes can be automated using orbital welding techniques. Such practice can result in fewer repairs, provided the bevels and alignment are within tolerance and the welding parameters are carefully selected.

WELDING filler Metals:

Filler Metals. Electrodes, bare wire, wire-flux combinations, and consumable inserts which form a part of the finished weld are classed as filler materials. Most are covered by AWS and ASME specifications.

What are Pipe fittings?

Fittings are fabricated pieces of pipe that are used to make: changes of direction (elbow), branch from a main pipe (tee), or make a reduction in line size (reducer) Fittings, like pipe, are manufactured and classified according to their wall thickness.

Flanges are primarily used where?

Flanges are primarily used where a connecting or dismantling joint is needed. These joints may include joining pipe to fittings, valves, equipment, or any other integral component within the piping system. To erect the piping system, every piece of mechanical equipment is manufactured with at least one outlet called a nozzle. The nozzle is the point where, via the flange, the piping system is connected to the equipment. From this flange, the piping system is begun.

PIPE FABRICATION/TRANSPORTATION TO FIELD TRANSPORTION OF SUBASSEMBLY TO SITE

For shipping, the ends of subassemblies are equipped with some type of end protection to preclude damage to weld end bevels or flange faces during shipment and field handling. See PFI Standard ES-31 ''Standard for Protection of Ends of Fabricated Piping Assemblies.''44 During shop operations, it is common practice to move piping assemblies with overhead or floor cranes, usually with chain or wire rope slings. For austenitic stainless steels and nonferrous materials which could be damaged or contaminated, use of nylon slings is recommended.

PIPINGFABRICATION PROCESS-2: Forming:

Forming. The term forming as it relates to piping fabrication encompasses *bending, *extruding, *swaging, *lapping, and *expanding. All of these operations entail the use of equipment normally only available in pipe fabrication shops. Although the availability of welding fittings in the form of elbows, tees, reducers, and lapped joint stub ends may reduce the need for certain of these operations, economics may dictate their use, especially where special pipe sizes are involved.

INSTALLATION HEAT TREATMENT

Heat Treatment.'' The heating units are applied to the section of the pipe to be bent. The section of the line upstream of the area to be bent should be anchored to preclude translation or rotation of the installed portion of the line. The anchor should preferably be not more than one or two pipe diameters from the area to be heated. Once the bend area has attained the required temperature, a bending force can be applied on the downstream leg of the pipe until the required bend arc has been obtained. Since most ferritic materials still have reasonably high yield strengths even at lower critical temperatures, care should be exercised. Large bending forces may damage the building structure or crack the line being bent. Apply a reasonable force for the conditions and allow the imposed stress in the bend arc to be relieved by the heat. Then repeat. Progress in this fashion until the required bend is accomplished. Some small amount of overbending may be required to offset the deflection which will occur in the unheated section of pipe between the heated arc and the pulling device. When the bend is completed and allowed to cool, all restraints may then be removed. Little if any force should be needed to align the downstream joint; otherwise additional bending may be needed to further correct the situation.

What does boilers/heaters do

Heaters, or furnaces as they are also known, are used to raise the temperature of a feed stock to the point where it can be used in a process facility. Some feeds, like crude oil, must be heated to approximately 700°F before it can be piped into a fractionation column. Lining the interior walls of a heater are pipes that travel in a continuous S or U pattern. Burners, fueled with oil or gas, are used to generate the extreme temperatures required in a heater. Heaters can be of the vertical or horizontal type. Boilers use the same principle as a heater. They are used primarily to generate super heated steam or stripping steam. Constructed similar to a heater, boilers can raise the temperature of water or condensate to 1,000°F or more.

INSTALLATION 1) Drawings

In all cases where prefabricated subassemblies are being erected, these drawings will have been marked up to show the locations and mark numbers of the individual subassemblies, the location and designations of field welds, and the locations and markings of hangers.

FABRICATION/ TOLERANCE: Talk about Tolerances in fabrication:

In order to assure installation of a system within a reasonable degree of accuracy, all the components involved must be fabricated to some set of tolerances on those dimensions which affect the system length. Tolerances on valve dimensions are given in B16.34,12 those of welding fittings in B16.9,13 flanged fittings in B16.5, B16.1,14 erances.''15 and those for flanges and etc. The assembly of these components will result in ''tolerance stack-up,'' which could have a significant impact on the overall dimensions, particularly in a closely coupled system. Sometimes assemblies which have been fabricated within tolerance may not fit in the field because of tolerance stack-ups on equipment to which they are attached. This will be addressed in the section, ''Installation.'

DESIGN DOCUMENTS INTRODUCTION

In today's atmosphere of complex projects, extended liabilities, tight cost controls, and strict quality standards, it is essential that all phases of a project, from inception to operation, be effectively communicated and correctly executed. To this end, contract documents, design documents, fabrication details, procedures, and specifications are developed to communicate, monitor, and document the design, fabrication, and erection of piping systems precisely. The number and variety of documents to be prepared for a particular piping system are determined not so much by the importance of the piping system as by the complexity of the system and by the interface requirements of the owner, the design organization, the contractor, the material suppliers, and the regulatory agencies. In the following sections, the documentation requirements of a complex project are illustrated to provide a broad overview of the hierarchy of documents. However, since the specific requirements of a project are driven by many variables, such as the owner's requirements, budgets, market conditions, company practice, and licensing requirements, the discussion here should be considered as a guideline only.

PIPING FABRICATION/ VERIFICATION 6.1 Meaning of Inspection

Inspection is the verification activity performed by the owner or the owner's agent. The manner in which an inspector verifies compliance is generally left to the discretion of the individual. It may take the form of detailed visual examinations; witnessing of actual operations such as bending, welding, heat treatment, or NDEs; review of records; or combinations thereof. Much relies on the degree of confidence the inspector has in the fabricator's programs and personnel. B31.3 has mandatory sampling requirements for this activity

PIPING FABRICATION/ VERIFICATION Differentiation btw inspection, examination, testing and QA/QC

Inspection relates to those activities performed by the owner, the owner's agent, or a third party. All other activities are usually performed by fabricator personnel. The term examination is applied to nondestructive methods of examination,while testing refers to traditional hydrostatic and pneumatic tests for leakage. QA and QC relate to in-plant or on-site programs, whose function is to control the various activities which affect quality.

PIPING FABRICATION-6.0 Verification Activities— Inspection, Nondestructive Examination, Testing, and Quality Assurance and Quality Control Introduction.

Introduction. Activities involved in verifying that fabrication meets the specified quality level may be broadly categorized as inspection, NDE, testing and QA and QC. The terms inspection, examination, and testing are still often used interchangeably. The ASME Boiler and Pressure Vessel Codes have begun to establish specific definitions for these terms. The B31 Codes present a mixture of usages, some following the ASME Boiler and Pressure Vessel Code lead, while others are less definitive. The reader is directed to the individual codes to see how these terms are used. In general, the ASME Boiler and Pressure Vessel Code practice will be followed in this section. Inspection relates to those activities

INSTALLATION JOINT ALIGNMENT

Joint Alignment In aligning weld joints for field welding it may be necessary to compromise between a perfect weld fit-up and the location of the opposite (downstream) end of the assembly. The weld bevel may not be perfectly square with the longitudinal axis of the assembly. Even a ¹⁄₃₂-in (0.8 mm) deviation across the face of the weld bevel can result in an unacceptable deviation from the required downstream location if the joint is aligned as perfectly as possible. Often such a small gap can be tolerated in the welding. If, in order to maintain the downstream location, the gap at the joint is excessive, the joint should be disassembled, and the land filed or ground as needed to attain the required alignment of the weld joint while still maintaining the required downstream position. Flanged connections should be made up handtight so that advantage can be taken of the bolt-hole clearances to translate or rotate the assembly for better alignment of downstream connections.

PIPING FABRICATION PROCESS-3 Layout, Assembly, and Preparation for Welding.

Layout, Assembly, and Preparation for Welding. In fabrication shops, piping subassemblies are often assembled on layout tables. A projection of the subassembly is laid out on the table in chalk. This establishes the baseline for locating the components and terminal dimensions of the subassembly, and the components are assembled relative to the layout. Preparation for welding: Prior to fit-up, it is essential that all weld surfaces be properly cleaned of rust, scale, grease, paint, and other foreign substances which might contaminate the weld. If moisture is present, the weld joint should be preheated. For alloy steels the heat-affected zone (HAZ) which results from thermal cutting should be removed by grinding or machining.

PIPING FABRICATION/VERIFICATION/EXAMINATION/NDT 6.2.2.4

Liquid penetrant examination: Penetrant-type examinations are suitable for surface examinations only but are very sensitive. They require a fairly smooth surface, since surface irregularities such as grinding mark indications can be confused with defect indications. The surface to be examined is thoroughly cleaned with a solvent and then coated with a penetrating-type fluid. Sufficient time is allowed to permit the fluid to penetrate into surface discontinuities. The excess penetrant is removed by wiping with cloths until all evidence of the penetrant is removed. A developer which acts somewhat like a blotter is then applied to the surface. Thisdraws the penetrant out of the discontinuity, and it will appear on the surface as an indication. Obviously, the success of the examination depends on the visibility of the indication. To enhance this, the penetrant contains colored dyes which can be seen under normal light, or fluorescent dyes which are viewed under ultraviolet light. The most common case is a red dye penetrant with a white developer

PIPING FABRICATION/VERIFICATION/EXAMINATION/NDT 6.2.2.4 Magnetic particle examination:

Magnetic particle examination: Magnetic particle examination is essentially a surface-type examination, although some imperfections just below the surface are detectable. This type of examination is limited to materials which can be magnetized (paramagnetic materials), since it relies on the lines of force within a magnetic field. The item to be examined is subjected to a current which will produce magnetic lines of force within the item. The surface is then sprayed with a fine iron powder. The powder will align itself with the lines of force. Any discontinuity normal to the lines of force will produce a leakage field around it and a consequent buildup of powder which will pinpoint the defect. The examination must be repeated at 90⬚ to detect discontinuities which were parallel to the original field.

Describe ladders

Many vessels and other pieces of equipment are built Figure 6-1. Horizontal vessel. Courtesy of Nisseki Chemical Texas, Inc., Bayport, Texas. to such great heights they become accessible only by ladders. Ladders allow workers to access the higher elevations of equipment for routine inspection and maintenance. Ladders are made of steel bar and plate, and are welded or bolted to the exterior of a vessel.

INSTALLATION CUTTING

Mechanical and oxyfuel gas cutting are most commonly used in the field. Plasma cutting may occasionally be used.

What are equipments?

Mechanical equipment is used to start, stop, heat, cool, liquefy, vaporize, transfer, store, mix, or separate the commodity flowing through the piping system. Although components such as pipe, fittings, flanges, and valves, which are used to transport various commodities from one location in a piping facility to another, are important and impossible to do without, they play a minor role in the actual manufacturing of a salable product. Other components of a piping facility actually perform the tasks for which the facility is being built. These items are known collectively as mechanical equipment.

INSTALLATION NDE IN THE FIELD

NDE in the field will follow the practices outlined in the section ''Verification Activities.'' Radiography is usually limited to radioactive isotopes, although occasionally X-ray equipment may find a use. Most surface examination is conducted using liquid-penetrant methods, since magnetic particle equipment is not as convenient in the field. Ultrasonics are used for thickness verification and in certain situations as an alternative to radiography of welds when permitted by the governing code.

What is a utility station

Organization is essential to quality design. Organizing a piping facility with maintenance in mind is crucial to efficient plant operation. Small independent maintenance centers called utility stations are located throughout a piping facility. Utility stations provide maintenance and operational personnel with centralized locations to find water, air, steam, and occasionally nitrogen. Utility stations are placed throughout a facility in such a manner to allow a utility hose 50⬘-0⬙ long to cover designated areas.

What is piping

Piping includes pipe, flanges, fittings, bolting, gaskets, valves, and the pressurecontaining portions of other piping components. It also includes pipe hangers and supports and other items necessary to prevent overpressurization and overstressing of the pressure-containing components. It is evident that pipe is one element or a part of piping. Therefore, pipe sections when joined with fittings, valves, and other mechanical equipment and properly supported by hangers and supports, are called piping. The term piping refers to the overall network of pipes, fittings, flanges, valves, and other components that comprise a conduit system used to convey fluids

INSTALLATIONS/Erection Planning Preliminary Check

Planning is vitally important in installing a piping system. Many factors must be considered, among them accessibility to the building location, coordination with other work, availability and accessibility of suitable welding and heat treatment equipment, availability and qualification of welders and welding procedures, rigging, scaffolding, and availability of terminal equipment. Each of the system components should also be carefully checked to assure correctness. -Valves and other specialty items in particular should be checked to assure they are marked with flow arrows, -that the handwheels or motor operators are properly oriented, and -that the material to be welded is compatible with the material of the piping. -Special valves for use in carbon steel systems are sometimes furnished as 5 percent chrome material, and thermowells are often not of the same chemical composition as the pipe. This may not be apparent from the drawings. Such a preliminary check will indicate the need for alternate welding procedures and preclude problems later.

Describe a platform?

Platforms are like small elevated walkways around the outside of a vessel or between equipment and structures. Usually 3'-0" wide, they have a floor made of steel grating or plate. With 3' tall handrails, workers can safely operate, inspect, and maintain a vessel. Platforms are spaced so ladders will not have a vertical run of more than 30'-0", but are not spaced closer than 8'-0" to provide adequate headroom clearance. A typical vertical ladder and cage are shown in Figure 6-5. Platform walkways are also depicted spanning between storage tanks in

Describe pumps?

Pumps, are mechanical devices used to move fluids under pressure from one location to another. Pumps accelerate the speed at which a commodity travels within a pipe, thereby increasing its rate of flow. Pumps used in piping facilities will be one of the following classifications: centrifugal, reciprocating, or rotary.

PIPING FABRICATION 5 Heat Treatment

Purpose: Heat treatment during piping fabrication is performed for a variety of reasons (i.e., to soften material for working, to relieve fabrication stresses, to restore metallurgical and physical properties, etc.). During fabrication, ferritic steels undergo phase changes during heating and cooling, while the austenitic stainless steels and nonferrous piping materials do not; consequently differing criteria must be applied.

PIPING FABRICATION/VERIFICATION/EXAMINATION/NDT 6.2.2.4 NDE Qualification of procedures and personnel

Qualification of procedures and personnel used in NDEs are required by most codes. When ASME Section V or API-1104 are invoked by the referencing code, a written procedure is required and it must be demonstrated to the satisfaction of the AI, ANI, owner, or owner's agent, whichever is applicable. Similarly personnel who perform NDEs must be trained, qualified, and certified.

PIPING FABRICATION/VERIFICATION/QA-QC 6.3

Quality Assurance and Quality Control. ASME Section III has very specific requirements for QA programs. ASME Section I has requirements for QC programs. The B31 Piping Codes do not require any formal written program at this time. Refer to these codes for detailed information on this subject.

Which fitting is used to make a reduction in the line size of a run of pipe? _

REDUCERS When the piping designer wants to reduce the diameter of a straight run of pipe, a reducing fitting must be used. Appropriately named, the reducer is available in two styles as: Concentric—having a common centerline. Eccentric—having offset centerlines.

PIPING FABRICATION/VERIFICATION/EXAMINATION/NDE 6.2.2 Radiographic examination

Radiographic examination: When the need for greater integrity in welding must be demonstrated, the most frequently specified examination is radiography. Since the internal condition of the weld can be evaluated, it is referred to as a volumetric examination. Radiographic sources used for examination of piping are usually X-rays or gamma rays from radioactive isotopes.

FABRICATION/DRAWING What do you understand by shop details?

Shop Details. A piping system prefabricated at a commercial pipe fabrication shop is usually divided into subassemblies or spools. The manner in which a system is divided depends on many factors: available lengths of straight pipe, dimensional and weight limitations for shipping and heat treatment, field welding clearance requirements, and sometimes scheduling needs. Bending, forging, special heat treatment, cleaning, and as much welding as possible are normally performed in the shop. Every attempt is made to minimize the number of field welds, but this must be balanced economically against the added costs of transportation and greater field rigging problems because of larger, heavier, more complex assemblies. Where the site conditions are adverse to normal field erection practices, much of the plant can be fabricated in modules for minimal onsite installation work. Once the number and locations of field welds have been decided, the fabricator will prepare detailed drawings of each subassembly. Each subassembly drawing will show the required configuration; all necessary dimensions required for fabrication; reference to auxiliary drawings or sketches; size, wall thickness, length, alloy, and identification of the materials required; code and classification; reference to special forming, welding, heat treatment, NDE, and cleaning requirements; need for third-party inspection; weight and piece identification number.

EQUIPMENT TERMINOLOGY The following list identifies items generally associated with mechanical equipment and vessels:

Skirt fireproofing. Generally brick or gunite, fireproofing is applied around the interior and exterior walls of a vessel skirt. It is necessary to prevent damage to vessel skirt in case a fire occurs. • Nozzle. The tie-in connection between the vessel or equipment and the piping system. Nozzles are provided in locations where a commodity is either introduced or removed from a vessel or piece of equipment. • Nozzle orientation. The angular arrangement of nozzles around the perimeter of a vessel's shell. • Nozzle projection. Used to establish the distance from the vessel's centerline to the nozzle's face of flange. Reinforcing pad. A plate contoured to the shape of a vessel shell. It is positioned around nozzles and provides additional strength in the areas where metal was removed from the shell. • Manholes. Similar to large nozzles that allow workers entry points into a vessel. They generally are 18⬙ ID and are accessible by ladders and platforms. When not in use, the manhole is sealed with a blind flange. • Manhole hinge. A hinge that creates a pivot point allowing the blind flange attached to the manhole to be easily removed for worker entrance. • Seal pan. A tray installed below the bottom tray in a vessel to prevent liquids from bypassing the trays. • Trays. Flat metal plates spaced approximately 18⬙ to 24⬙ apart inside a vertical vessel. They can be bolted or welded to the vessel shell. Trays are perforated to allow rising vapors and falling liquids to pass through with the aid of a valving mechanism called a cap. • Weir. A dam-like plate welded on a tray that allows a fractionated by-product to collect and be extracted by a nozzle. • Downcomers. Openings adjacent to a tray that allow liquids flowing over a weir plate to fall to the tray below and begin the fractionation process over again. • Insulation rings. Continuous circular rings welded to the exterior of a vertical vessel that support a vessel's insulation. They are typically spaced on 12⬘-0⬙ centers. • Saddles. U-shaped supports welded on horizontal vessels and exchangers. Saddles are bolted to concrete foundations and create a cradle-like support in which the vessel can rest. • Lifting lugs. Donut-shaped rings welded to the vessel's shell or head that allow the vessel to be raised and positioned during installation.

FABRICATION PROCESS/FORMING-2b Other Forming Operations. Some additional forming operations which can be performed in a pipe shop are extrusion, swaging, and lapping.

Some additional forming operations which can be performed in a pipe shop are extrusion, swaging, and lapping. *Extrusions involve forming outlets in pipe by pulling or pushing a hemispherical or conical die from the inside of the pipe through an opening in the wall. The work may be done hot or cold depending on the characteristics of the material. Ferritic steels, austenitic steels, and nickel alloys are usually formed hot; aluminum and copper are usually formed cold. In order to assure that the outlet will have sufficient reinforcement, it is necessary to increase the wall thickness of the header as a function of the outlet size desired. An increase of 30 percent may be needed for large outlet-toheader ratios. *Swaging involves the size reduction of pipe ends by forging, pressing, or rolling operations. The operation is usually used to produce reductions of one to two pipe sizes. Ferritic steels, austenitic steels, and nickel alloys are usually formed hot. Aluminum and copper are formed cold. *In lapped joints, a loose flange is slipped over the end of the pipe which is then heated to forging temperature, upset, and flared at right angles to the pipe axis. After heat treatment and cooling, the lapped section is machined on the face to attain a good gasket surface and on the back for good contact with the flange. The finished thickness of the lapped flange should be equal to or exceed the thickness of the pipe.

FUNCTIONS FROM VALVES ARE:

Stopping and starting flow Reduce or increase a flow Controlling the direction of flow Regulating a flow or process pressure Relieve a pipe system of a certain pressure When fluid pressure builds up beyond a set limit, the valves relieve the overpressure to safeguard the integrity of the piping system or a component. Valves help in maintaining or breaking a vacuum. Valves also assist in maintaining the pressure or temperature of the flow medium within the desired range or limit.

What are storage tanks used for?

Storage tanks are used in several phases of the refining process. -They can be used to store crude oil prior to its use in the facility, -as holding tanks for a partially refined product awaiting further processing, -or to collect a finished product prior to its delivery or pick-up by a customer. Usually placed within a common area of a facility known as a tank farm, storage tanks come in various shapes and sizes. Some are shaped similar to horizontal vessels and some are spherical, like a ball. The majority of storage tanks, however, are huge, ground-supported vessels, as much as 200 feet in diameter and up to 60 feet tall. Spherical tanks are used primarily for storing liquefied petroleum gases like butane, methane, or propane. The larger tanks, used for storing liquid product, will have either a conical, elliptical, open, or a floating roof. Floating roofs raise and lower to automatically adjust to the level of the commodity in the tank. Floating roofs help reduce evaporation and prevent the buildup of dangerous gases that often occur with flammable liquids. As a preventative measure, dikes are erected to contain major leaks or spills. Should a storage tank rupture or suffer severe damage, a dike would prevent major contamination to surrounding areas. Dikes can be earthen dams or concrete walls built around a storage tank at a height that would contain the entire contents of the storage tank should a spill occur.

PIPING FABRICATION/VERIFICATION/TESTING 6.3 TESTING

Testing. All of the piping codes outline some type of pressure test to determine leak tightness. Since the completed piping system is usually subjected to some type of test in the field after installation, shop testing of subassemblies is infrequent. In those cases where the assembly cannot be field tested, where welds in the assembly will not be exposed for examination during the field test, and in other special situations, shop testing may be required. Shop testing must meet all of the requirements for field testing. See the section ''Installation'' for particulars.

What does a compressor do?

The compressor is similar to the pump, but it is designed to move air, gases, or vapors rather than liquids. The compressor is used to increase the rate at which a gaseous commodity flows from one location to another. Gases, unlike liquids, are elastic and must be compressed in order to control their flow characteristics. Like pumps, compressors are manufactured in centrifugal, reciprocating, and rotary configurations

What is a flange?

The flange is a ring-shaped device designed to be used as an alternative to welding or threading various piping system components used throughout the piping system. Flanged connections are used as an alternative to welding because they can be easily disassembled for shipping, routine inspection, maintenance, or replacement. Flanged Flanged connections are preferred over threaded connections because threading large bore pipe is not an economical or reliable operation. The flange is an important component of any piping system.

What are Horizontal Vessels/Accumulators used for

The horizontal vessel, is a cylindrical-shaped storage tank whose long axis is parallel to the horizon. It is used primarily as a receiving and collecting container for liquids and, therefore, has no internal moving parts. Support saddles are welded on the underside of the vessel to prevent it from rolling off its concrete foundations. A nozzle on the top of the vessel allows liquids to enter and fill the vessel. A nozzle on the bottom allows the liquids to be drawn out. Smaller nozzles can be used for venting and instrumentation attachment. Instruments are needed to measure the level of the commodity within the vessel. A large diameter nozzle, typically 18"ID, called a manway, provides an entrance for a worker into the vessel for internal inspection and maintenance.

FABRICATION/PROCEDURES Discuss the term Procedures and Travelers

The need to assure better control of fabrication processes has led the use of written procedures for most operations. Fabricators will have a library of written procedures controlling *cutting, *welding, *bending, *heat treatment, *nondestructive examination, and *testing. Welding procedures in most codes are qualified under ASME Section IX, which requires written Welding Procedure Specifications (WPSs) backed up by Procedure Qualification Records (PQRs). Similarly ASME Section V requires NDE to be performed to written procedures. Frequently, piping fabricators use a system of travelers to control flow through the shop. This practice is well-suited to fabrication of piping subassemblies under QA or QC programs, where record keeping is required. It also affords the purchaser and the third-party inspector opportunities for establishing ''hold points'' where they may wish to witness certain operations or review certain records.

What does a reboiler do

The reboiler, as the name implies, is used to replenish the temperature of a commodity. Two types of reboilers are used; the kettle-type and thermosyphon. A kettle-type reboiler is similar in design to the shell and tube exchanger. The thermosyphon reboiler is attached directly to the bottom of a fractionating tower. . Reboilers are used to keep fluids, which are circulating through a tower, at their boiling point. The process commodity enters the reboiler from the tower in a liquid state, is heated by either super heated steam or another hot liquid, and is returned in a vaporous state to an area in the tower called the flash zone. .

what is installation

The term installation refers to the physical placement of piping subassemblies, valves, and other specialty items in their required final location relative to pumps, heat exchangers, turbines, boilers, and other equipment; assembly thereto by welding or mechanical methods; final NDE; heat treatment; leak testing; and cleaning and flushing of the completed installation.

INSTALLATION Pipe Supports

This section offers some thoughts on the installation of piping supports

INSTALLATION Mechanical Joints

Threaded joints probably represent the oldest method of joining piping systems. Where the presence of a joint comFIGURE A6.27 Threading die. pound is undesirable, dryseal pipe threads in accordance with ASME B1.20.346 may be employed. Flanged joints are most often used where disassembly for maintenance is desired. Gasket surfaces should be carefully cleaned and inspected prior to making up the joint. Damaged or pitted surfaces may leak. Appropriate gaskets and bolting must be used. The flange contact surfaces should be aligned perfectly parallel to each other. Attempting to correct any angular deviation perpendicular to the flange faces while making up the joint may result in overstressing a portion of the bolts and subsequent leakage. The proper gasket should be inserted making sure that it is centered properly on the contact surfaces. Bolts should be tightened hand-tight.

Types of Weld tee

Two types of tees are used in the piping industry: • Straight—all three outlets are the same pipe size. • Reducing—branch outlet is a smaller pipe size. The name of this fitting comes from its resemblance to the letter T. It is a three-way fitting used to make perpendicular connections to a pipe. Lines that connect to the main run of pipe are known as branches. The main run of pipe is often called the header

PIPING FABRICATION/ VERIFICATION 6.2 examination: meaning and types

Types of Examinations. When used in the various codes, examination refers to the verification work performed by employees of the fabricator, much of which falls into the category of NDE. NDEs most often referenced by code and applied to the fabrication and installation of piping components and systems are: Visual Radiographic Ultrasonic Liquid penetrant Magnetic particle Eddy current examination is often used to evaluate the quality of straight lengths of pipe as they are manufactured but is not often used in fabrication activities. Although not referenced by most codes, bubble testing, halogen diode probe testing, or helium pass spectrometer leak testing may be invoked by contract when, in the opinion of the designer, they will contribute to the integrity of the system. Accept-reject criteria and the extent to which the various NDEs are to be applied are in the applicable code.

PIPING FABRICATION/VERIFICATION/EXAMINATION/NDT 6.2.2.3 Ultrasonic Examination

Ultrasonic examination: Ultrasonic examination is used in piping for the detection of defects in welds and materials as well as for determining material thickness.

What are valves

Valves are mechanical devices that controls the flow and pressure within a system or process. A valve is a device that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways.

Describe a Vertical Vessels/Fractionation Columns

Vertical Vessels/Fractionation Columns The vertical vessel is a cylindrical vessel whose long axis is perpendicular to the horizon . Easily the most visible piece of equipment, some vertical vessels can exceed 200 feet in height. Fractionation columns have internal plates called trays that aid in the separation and collection of the various molecular compounds of a feed stock. The process of breaking down a feed stock into its molecular compounds is called fractional distillation. After further refinement and processing, these compounds will become by-products such as diesel, gasoline, kerosene, and many others

PIPING FABRICATION/VERIFICATION/EXAMINATION/NDE 6.2.1 VISUAL EXAMINATIONS

Visual examination is probably the oldest and most widely used of all examinations. It is used to ascertain alignment of surfaces, dimensions, surface condition, weld profiles, markings, and evidence of leaks, to name a few. In most instances the manner of conducting a visual examination is left to the discretion of the examiner or inspector, but more recently, written procedures outlining such things as access, lighting, angle of vision, use of direct or remote equipment, and checklists defining the observations required are being used. Visual examination takes place throughout the fabrication cycle along with QA and QC checks. At setup, this would consist of verifying: materials, weld procedures, welder qualifications, filler metal, and weld alignment, and On completion of fabrication, such things as: terminal dimensions, weld profile, surface condition, and cleanliness

What are water system roles?

Water Systems Often taken for granted, water systems play an important part in a piping facility's successful operation. Water systems can include cooling water, boiler water, plant water, utility water, and emergency water.

WELDING Welding processes

Welding Processes. Currently the most commonly used welding processes for fabrication of piping are: Shielded Metal Arc Welding (SMAW), submerged arc welding (SAW), Gas tungsten arc welding: GTAW, Gas metal arc welding: GMAW, and flux core arc welding (FCAW). Some special applications may involve plasma arc welding (PAW) or electron beam welding (EBW), but their application to piping is still rare

PIPING FABRICATION: 4 WELDING procedure and personnel qualification

Welding constitutes the bulk of the work involved in fabrication of modern piping systems, so it is essential for all involved to have a good working knowledge of this subject. *Procedure and personnel Qualifications: All of the ASME Boiler and Pressure Codes and most of the ASME B31 Pressure Piping Codes reference ASME Section IX for the requirements for qualifying welding procedures and welding personnel. The purpose of procedure qualification is to assure that the particular combination of welding process, base metal, filler material, shielding fluxes or gases, electrical characteristics, and subsequent heat treatment is capable of producing a joint with the required chemical and physical characteristics. The purpose of personnel qualification is to assure that the welder or welding machine operator is capable of performing the operation in accordance with a qualified procedure in the required position. Procedure qualification: ASME Section IX requires the preparation of a welding Procedure Specification (WPS), which lists the various parameters to be used during welding. When each was is qualified, the parameters used in the qualification are recorded in a Procedure Qualification Record (PQR). Personnel Qualification. The fabricator and/or installer must qualify each welder or welding operator for the welding processes to be used during production welding. The performance qualification must be in accordance with a qualified WPS. Each performance qualification is also governed by a series of essential variables which are a function of the welding process for which the welder is being qualified.

Everyday use of valves

When you turn on a faucet (tap) to brush your teeth, you're opening a valve that allows pressurized water to escape from a pipe. Similarly, when you flush the toilet, you open two valves: one that allows water to escape to empty the pan and another (called a ball valve or ballcock) that admits more water into the tank ready for the next flush. If you have a gas cooktop (hob) on your stove, the controls that turn the gas up or down are valves. When you turn up the heat, you're opening a valve that allows more gas to flow in through the pipe. More gas burns with a bigger flame so you get more heat. Valves are pretty much guaranteed to be in any machine that use liquids or gases

What are Piping Systems?

Within every piping facility there are specific piping systems that perform specialized functions. These systems vary in their importance to the overall operation of the facility and can range from vital to peripheral. These systems can be complex in design or simple in function.

PIPING FABRICATION/VERIFICATION/EXAMINATION/NDT/RADIOGRAPHY 6.2.2.1 X-RAY

X-ray equipment is often used, it has limitations in that it often requires multiple exposures for a single joint, and special equipment, such as linear accelerators, are needed for heavier thicknesses. Although X-ray machines produce films with better clarity, they are not as practical in the field because of space limitations and portability. In the field, radioactive isotopes are used almost exclusively because of their portability and case of access.

Types of equipments

a) Horizontal Vessels/Accumulators b) Vertical Vessels/Fractionation Columns c)Ladders, Cages, and Platforms d) Pumps e) Compressors f) Exchangers g) Cooling Towers h) Heaters/Boilers I) Storage Tanks

What are plant utilities

plant utilities provide services that are essential to the efficient operation of the piping facility. Utilities include systems such as water, steam, condensate, fuel oil and gas, flares, and air. Types a)Water Systems b) Fuel Oil and Fuel Gas c) Flare Systems d) Air Systems:There are two types of air systems: utility air and instrument air c) Control valve manifold d) UTILITY STATIONS e) meter run f) SEWER AND UNDERGROUND PIPING SYSTEMS

.......are mechanical devices used to move fluids under pressure from one location to another

pumps

what is fabrication?

term fabrication applies to the cutting, bending, forming, and welding of individual pipe components to each other and their subsequent heat treatment and nondestructive examination (NDE) to form a unit (piping subassembly) for installation.

Conversation from inches to foot.

there are 12 inches (") in one foot(') , so you can get from inches to feet by dividing by 12.

Types of flanges

weld neck • threaded • socket weld •slip-on •lap-joint • reducing •blind •orifice