Have you seen the message displayed in your Caesar II dashboard whenever you open your Caesar II Program saying “CAESAR II will no longer respond to HASP keys after May 31, 2020.” as shown in Fig. 1
Yes, you got it right. Intergraph, i.e Hexagon is changing their licensing system from HASP (Hardware Lock) or SPLM (Smart Plant License Manager) Licensing to Intergraph Smart Licensing (ISL) from June 1st, 2020 onwards. Hence, if your current licensing is on the HASP Key platform, you must transition it to smart licensing.
Fig. 1: Caesar II Warning for ISL Transition
What is Intergraph Smart
Licensing?
Intergraph Smart Licensing or ISL, in short, is the next-generation cloud server-based advanced software licensing product from Hexagon PPM.
Smart Licensing Cloud contains servers with license keys. The cloud servers with license keys will be connected to a website portal. This portal will be accessible from a browser with the help of an internet connection. License administrators will be able to use the portal for setting up the configurations and generating license keys. Smart Licensing Client is basically a small application that has to be installed on each client computer where a licensed application is running. A configuration connection info (.cci) file will be used to connect the client computer to the cloud for licensing. Once you open the Smart Licensing Client, you can easily view, change, update settings and check whether licenses are in or out.
Advantages of ISL
As per Hexagon PPM, ISL will offer many benefits with respect to the earlier system like
It will be very easy to install, use and administration.
It is expected to reduce your costs as it will eliminate the requirement of maintaining the license server.
the risk of losing the expensive hardware locks will be eliminated.
As the ISL will be through the internet, so one can work from anywhere without the geographical limitation of the office.
In Smart Licensing Client, one can change projects and settings as and when required.
It may support offline working as well
Comparison between SPLM and ISL
Smart Licensing, ISL provides more features and enhanced usage reporting. Refer to the following table that compares features in the previous licensing solution and the current licensing solution.
Table 1: SPLM vs ISL
ISL Webinar
There is a recorded webinar by Hexagon regarding the background of Smart Licensing and steps to follow for changing your current licensing into a Smart Licensing system. Refer to the webinar to understand more details about ISL.
Major discussion points of the webinar
In this online webinar You will
learn about:
The Transitioning from SPLM or ESL (dongles) to
ISL
The new solution rollout of the ISL
About the Presenter
Geoff Blumber, Technical Sales Manager – Hexagon PPM: As the Technical Sales Manager at Hexagon PPM, Mr. Geoff Blumber is aligning the people and resources to deliver the right solutions to the right people at the right time.
Bryan Stuckey, CADWorx Technical Manager – Hexagon PPM: Mr. Bryan Stuckey who serves the role of CADWorx Technical Manager joined Hexagon PPM in March 2013. He has huge experience with multiple 3D platforms ranging from software administration to modeling. He provides end-user technical support, product testing, and training/presentation support for CADWorx Plant Design Suite.
Spectacle blinds and Spacers are pressure-retaining devices used in the piping/pipeline industry to temporarily or permanently blind (shut) or isolate part of the piping or pipeline system.
A spectacle blind is a forged product and a combination of a flange spade and a ring spacer in one single product.
One end of the spectacle blind will have an opening that allows fluid flow through the pipe during operation and the other end is made solid to block flow during isolation or maintenance time.
One can simply rotate the spectacle blind by 180 degrees to close or open the fluid flow through the piping system.
However, when there is space constraint, Flange spades and ring spacers can be used as separate products.
As one of the two discs is always outside the pipe, one can easily understand if the blind is in an open or closed position.
As it looks like the numeric number Eight or a pair of eyeglasses, a Spectacle blind (Fig. 1 & 2) is also known as a figure 8 blind or figure 8 spectacle blind.
Design Code and Standards for
Spectacle Blind
ASME B16.48 is the governing code for spectacle blind design. This specification provides the dimensions, pressure-temperature ratings, materials, marking, dimensional tolerances, and testing requirements of the Spectacle blind. In general, Blinds are available in sizes NPS 1/2 – NPS 24, and these are installed between ASME B16.5 piping flanges in the 150, 300, 600, 900, 1500, and 2500 Pressure Classes. They are manufactured from steel plates and are available in forged material grades like ASTM A105 (high-temperature carbon), A350 (low-temperature carbon), and ASTM A182 grades (alloy, stainless steel, duplex).
Bigger size spectacle blinds with a diameter of>24 NPS are also available, but these are custom-made. Spectacle blinds of Carbon steel Material are normally manufactured from a single piece of steel, whereas alloy / stainless steel blinds can be produced by welding more pieces together.
Various spectacle blind standards used in industrial applications are:
DIN Standards for Spectacle blind: DIN 2527, DIN 2566, DIN 2573, DIN 2576, DIN 2641, DIN 2642, DIN 2655, DIN 2656, DIN 2627, DIN 2628, DIN 2629, DIN 2631, DIN 2632, DIN 2633, DIN 2634, DIN 2635, DIN 2636, DIN 2637, DIN 2638, DIN 2673
BS Standards for Spectacle Bild and Spacer: BS 4504, BS 4504, BS1 560, BS 10
Definition of Terms used with
Spectacle Blind
Ring Spacer or Spacer Ring or
Paddle Blank or Paddle Spacer
Spacer Rings are made to match the pipe ID with the same thickness as the “single-blind” that it replaces. During the installation of spacers, the flange and associated piping should be pulled together and a “ring spacer” has to be installed to fill the gap. Normally, a handle is attached to the blank by welding.
Single/ Line Blind or Blank or
Spacer Blind or Flange Spade or Paddle Blind
Single-blind is a positive shut-off device that is generally installed along with a valve so as to prevent accidental flow. In general, they fit inside the bolt circle of mating flanges. However, Plastic, Fiberglass, and Cast Iron, are bolted. Single blinds use standard gaskets.
To differentiate between a spacer and blind in the installed line, the handle of the blank is made solid whereas a formed eye or drilled hole is made for the spacer.
Spectacle Blind
A combination of a ring spacer and a single-blind is used as a spectacle blind. As required they are rotated to serve the purpose. When spectacle blinds become too heavy, a pair of paddle blank and paddle spacer is used instead of a single spectacle blind.
During leakage testing, test blanks are used. Test blanks are specifically designed blanks and used only for testing purposes for the test duration.
Vapor Blind
Similar to a “single-blind”, Vapor Blinds are positive sealing devices used for preventing vapor leakage into a pipeline or vessel. Generally, they are thinner compared to single-blind and normally 1/8″ to 5/16″ (3-8mm) thick.
Jack Screw Flanges
For larger-size blinds, Jack Screw Flange is required. Jackscrew help in spreading the flanges and replacing the spacer/blind or turning of spectacle blind.
Use of Spectacle Blind, Spades, and Spacers
As Spectacle Blind, Spades and Spacers belong to the family of pipeline isolation devices, and they are used to provide flexibility during operation and maintenance. Hence, it is required to consider this during the design of the Piping system. Blanks are normally installed in a horizontal line. On average, spectacle blinds are installed on the following
The following spectacle blind symbol is used in P&ID to denote spectacle blind.
Fig. 4: Spectacle blind Symbol
Difference between Spectacle Blind and Spade and Spacers
Spade and Spacer combinedly are comparable to Spectacle Blind. So, a spectacle blind is the combined form of a spade and spacer. For larger pipe sizes the weight of the spectacle blind becomes too heavy. So sometimes, as the requirement arises, a spade or spacer is used. The word “SPADE” or “SPACER” are stamped on the handle of the spade or spacer to clearly indicate what is installed in the line.
In the installed position the handles of the spade and spacers are visible from the outside. The common handle configurations are provided below in Fig. 5
Fig. 5: Spade handle Configurations
Few important Considerations for Spectacle blinds
Spectacle blinds must be accessible from grade, platform, or if below 4500 mm by a portable ladder, or temporary scaffolding.
The proper weight of the Spectacle blind needs to be considered during pipe stress analysis when near the equipment nozzles.
The most common problematic area for a Piping/Pipeline System design is flanges. So we have to be doubly sure to seal it properly to prevent flange leakage. At the same time, It must also be insulated cathodically so that stray currents which are known behind the undue corrosion and eventual metallic breakdown be prevented. Insulating gasket sets or Flange insulation kits play an important role in such cases.
They are designed for electrically insulating the flanges.
They act as an insulator between dissimilar metallic flanges.
Also, they are used to isolate sections of pipework (dissimilar metals) electrically in the cathodic protection systems; thus preventing the electrostatic charge flow along the pipelines as they remove the possibility of galvanic cell system creation.
Major Applications of Insulating Gasket Kit
Insulating gasket kits can be used in all such places where galvanic corrosion protection and electrical insulation are needed. Common Application areas are piping/pipeline systems with seawater environments, offshore installations, chemical installations, oil refinery pipelines, etc.
Components of Flange Insulation Gasket Kit
Each flange
insulation Kit (Refer to Fig. 1) constitutes of
one central flat or oval
section gasket,
one insulation sleeve per bolt
and
two insulating steel washers
per bolt and
two plated steel washers per
bolt.
All these components are produced using special materials possessing chemical stability, dielectric properties, and low water absorption so that the purpose is solved. The full sets are packed individually and labeled clearly mentioning the flange size, rating, type, and material combination. Insulation kits are generally available upto 24 inches, but custom-made higher nominal sizes can be produced on the requirement.
Fig. 1: Components of Flange Insulating gasket Kit
Assembling of the flange insulation gasket kit components
The polyethylene insulating sleeve and the mounting stud are the main components of the insulating gasket kit. Contrary to the conventional nut and bolt system of flanged joints, the insulation kit uses a stud with a washer and nut on each end of the flange joint. The insulating sleeve is then inserted into the bolt holes using one insulator on each side of the flange. So, Two insulators per bolt hole are inserted into the flange. Then the mounting stud is inserted into the insulating sleeves until threads on each end of the stud are visible outside of the flange. A flat steel washer is slid onto the stud at each end, and a nut is threaded onto each end of the stud and tightened.
As a nut is tightened on each end of the stud, the flange insulation kit becomes much stronger than the typical nut-and-bolt type connection. In the traditional manner of nut-bolt tightening, all of the clamping force is applied to the single set of threads on the bolt while in the case of a double-ended stud such as in a flange insulation kit, the clamping force is divided equally between the threads on each end of the stud as well as inside both nuts. The stud is protected and insulated from any electric charge and corrosion. This creates a flanged connection that will not corrode or fail due to a chemical reaction between two dissimilar metals.
Types of Flange Insulating Gaskets
Four major types of gasket isolation kits are available in the market those are designated as F, E, D, & O. Each type of flange kit fits flanges with a specific type of flange face (RF, FF, RTJ).
F Type Gasket
Type F type gaskets are produced to fit the raised face flanges. The inside diameter of the bolt-hole circle is made slightly smaller than the external diameter of the gasket which assures automatic positioning of the gasket. To avoid the accumulation of foreign materials, Special band protectors can be used for the joint assembly to strengthen the cathodic isolation further. These are manufactured from 1/8″ thick fabric-based phenolic sheets either without coating or a with a nitrile rubber coating on the two faces. Type F gaskets are also available in non-asbestos fibers with high isolation capacity.
E Type gasket
In full-face type, Type “E” Gaskets, the outside diameter of the gasket matches the external diameter of the flanges. So the gasket completely covers the whole flange surface. There are produced with precision-located bolt holes and are easy to position in the center. This design will prevent foreign material accumulation between the flange faces and thus enhances the isolation properties of the kit. Type E flange insulation kits are available in phenolic, neoprene-faced phenolic, and high-temperature materials.
D Type Gasket
Type “D” Gaskets are manufactured to fit into the ring groove of RTJ flanges (style R, RX, and BX). They are available in medium weave reinforced phenolic and other materials are sized to ANSI specifications available in a basic oval as well as an octagonal shape. This type of gasket is known as an “API ring joint”.
O Type gasket
Type O Gaskets are extra special as they feature an additional sealing element on both sides of the device, generally, PTFE, Nitrile, or Viton Rubber, and are available in both ring and full-face designs (type E and F).
Insulating gasket Material
All materials should be selected to assure long-term effective sealing and electrical insulation of the flanged joints.
To take advantage of the best characteristics, sometimes, gaskets are made with combinations of materials.
Normal Gasket materials are G3, G7, Nitrile-Face, Plain Phenolic, G10, Neoprene-faced Phenolic, Klinger, Teflon, Durlon, etc. Popular Sleeve materials are Phenolic, Mylar, Polyethylene, Minlon, or Nomex. Common washer materials are Phenolic, Steel, G7, G3, or G10 available as a single washer and sleeve kit, a one-piece washer kit, a double washer kit, or a one-piece double washer kit (Minlon)
Sleeves and Washers of Flange Insulation Gasket Kits
One-piece sleeves and washers
One-piece sleeves and washers are available molded from acetal resin. They should generally be used as single washer sets since they are molded to specific lengths and are in many instances longer than the thickness of a single flange. They are available for bolt diameters of ½” to 1-1/2″ (12.7 mm to 38.1 mm), and are limited to applications where the flange temperature does not exceed +180^oF (+80^oC).
A special feature is a washer centering ring that positions the steel washer on the unit properly to avoid uneven pressures on the washers.
Insulating Washers
Standard insulating washers are made of high-strength phenolic and provide tough, positive insulation at temperatures of +3000F ( +1500C). They are available for bolt sizes from ½” (12.7 mm) through 3 ½” (88.9 mm) and are made to fit over the insulating sleeves. Fiberglass reinforced high temperature phenolic insulating washers are available on special order in the same sizes as the standard insulating washers
Insulating Sleeves
Insulating sleeves are available in Mylar, polyethylene, phenolic, and Nomex. They are through 3-1/2″ (88.9 mm) and are designed to fit easily over the flange bolts, and may be used with standard-sized bolts and bolt holes even with some misalignment. Insulating sleeves are used with separate insulating washers and have a standard wall thickness of 1/32″ (0.79 mm). They are available for standard American bolt sizes from ½” (12.7 mm) to 3 ½” (88.9 mm), as well as metric bolt sizes from 12 mm and larger.
Steel Washers
Steel washers are designed to fit over the insulating sleeve or retainer ring on the one-piece sleeves and washers. The outside diameter is sized to fit within the bolt facing on ANSI standard flanges. They are of 1/8″ (3.2 mm) thick plated hot-rolled steel. Pyrox insulating sleeves and washers are also available.
The Gasket ID (inside diameter) is normally made slightly smaller than the flange ID. While installing ensure that the gasket is properly centered over the bore. It will prevent the build-up of foreign material between the flange faces during pigging.
Single washer insulating sets are recommended for underground flanges. This should be installed on the unprotected side of the flange, which will provide cathodic protection for the studs as well as the nuts. For above-ground flanges, It is suggested to use Double washers for ease in testing.
The use of alignment pins is always suggested which will ensure proper alignment of flanges and gaskets. The size of each Pin shall be a minimum of 3/32″ (2.38 mm) larger than the bolt.
A diagram showing a recommended bolt tightening sequence is normally supplied with each insulating gasket set.
Common Vendors for Insulating Gasket Kits
Common vendors
who manufacture and supply insulating gaskets are
PSI
Pikotek
Central Plastics
Garlock
Trojan
Lemons
Advanced Products and Systems
Information needed for Ordering Flange Insulating Kits
To order an insulating gasket kit, the following information needs to be provided:
During the course of pipe stress analysis, we find a few lines in any complex project to have a very large diameter. Caesar II Support Modeling of such pipes always creates confusion on whether to consider radial thermal growth or to be modeled as centreline supporting. There is still confusion among several engineering organizations and the design approach varies. In this article, We will discuss pipe support modeling in Caesar-II, support selection, its detailing & functionality. In this article, Pipes /Pipelines having a diameter of more than 24’’ are considered large-diameter pipes.
Support Modeling Philosophy in Caesar II
Up to 24’’ pipe size, support shall be modeled at the centerline of the pipe i.e. the radial expansion of the pipe shall be neglected & support shall be assumed to be acting at the center of the pipe as shown in Fig. 1
For the Large diameter bare pipes (>26″ NB), the Stress Engineer shall model a rigid element from the center of the pipe to the bottom of the pipe up to the supporting point considering the pipe radial expansion as shown in Fig. 1.
Fig. 1: Pipe Support Modeling for bare pipes at Caesar II
For Large diameter insulated pipes, the temperature gradient and the actual point of action of guide and resting can also be fed as shown in Fig. 2.
Fig. 2: Pipe Support modeling for large-diameter insulated pipes at Caesar II
The stress engineer shall decide whether to provide the reinforcing pad or not at the support point (trunnion type) in the following cases:-
If the slope of the piping is more than 15˚, the Stress engineer shall decide whether to use a reinforcement pad or not, depending upon pipe size, support load, support function (Line Stop/Guide), unsupported pipe span, etc. Refer to Fig. 3 for an illustration.
Fig. 3: Use of R.F. Pad for Sloped Lines > 15˚
The reinforcement pad at the Directional Anchors or line stops for large pipes shall be used as shown in Fig. 4 below.
Fig. 4: Requirement of RF Pad for Supporting large diameter pipe
Irrespective of any size, the stress engineer shall provide a reinforcement pad for higher loads on the support based on the trunnion check calculation.
RF pad shall be provided at all support for thin pipes. The pipe shall be considered a thin-walled pipe if D/T> 96, where D is the outer diameter of the pipe and t is its thickness.
Wear Pad shall be used at all support locations in case of uninsulated large pipes
For large-diameter pipes, two or more bottom-type springs may be used as shown in Fig. 5, Fig. 6, and Fig. 7.
Fig. 5: Illustration of Two Bottom Springs used for Large pipes (Note: Provide stiffener plate if the shoe base plate extension is large)
Fig. 6: Illustrating Four Bottom Type Springs used at one Supporting Location with a guide for Large Pipes
Fig. 7: Illustration of Four Bottom Type Springs used for Large pipes
For large diameter pipes, it’s better to avoid single lug support due to the tendency of ovalization of the pipe because of Self-weight. Supporting shall be done using a pipe clamp or two trunnions having two different clamps instead of a single lug as shown in Fig.8.
Fig. 8: Use of clamps for supporting Large Pipes
Approach for Caesar Modeling Vs Actual Supporting
Generally, the following points are to be taken care of while converting Caesar II modeling into practical support. Depending upon supporting and practical function of the support we should revisit our Caesar II support modeling.
Supporting for guide modeled with zero gaps
Fig. 9: Guide modeling & supporting for Large Pipes
Supporting a guide with resting
Fig. 10: Modeling & supporting of Guide with resting for Large Pipes
These are a few standards practices. These may vary from one consultancy to another. Please provide your input in the comments section.
Few more articles related to piping supports for you..
Expansion Joints are one of the critical devices that piping stress engineers use in piping systems having less flexibility. But it becomes quite a headache to choose the right kind of expansion bellow and then model it exactly considering all real configurations. Whether to choose a tied one? or whether to consider the thrust force? Such questions always arise in our mind and most of the time remain unanswered simply because there are very little literature and description available for modeling and analysis of systems considering expansion joints.
So now we all have a chance to learn from the experts and clarify our doubts. Thanks to the Caesar II owner company, Hexagon PPM who has arranged a webinar on 25th February 2020 at 10:00 AM CST as per the below-mentioned details.
Expansion Joints in Caesar II
Webinar Details
Date and time: February 25th, 2020 at 10.00 AM CST (Please convert to your local time and mark it on the calendar else you may miss it)
Main Focus Points of the Webinar
This webinar will briefly throw light on the following points:
Various ways of expansion joint inclusion in the piping system.
Different types of expansion joint assemblies are available.
Selecting the appropriate expansion joint assembly.
Using the Caesar II Expansion Joint Modeler.
Zero-Length expansion joint.
Complex, Detailed Expansion bellow Model
Evaluating the joint
About the Presenter
David Diehl, P.E.: With more than 30 years of engineering and technical support experience is the Director of Training for CADWorx & Analysis Solutions – Hexagon PPM. He is the lead instructor for CAESAR II and the principal author of the CAESAR II online training course. He also served as a Director for the Society of Piping Engineers and Designers (SPED) for 16 years and currently, he is Chair of the B31.3 Process Piping Committee.
Injection and mixing points are locations used frequently in refineries, petrochemical, and power plants and carry a potential risk of increased degradation rate compared to the mainline due to the changes in temperature, pH, phase changes, and the concentration of corrosive species. Because of that, dedicated publications and literature addressed the requirements for the design and inspection of the mixing areas
Figure 1: Injection points
What is an Injection Point?
Injection Point: Injection Points are locations where chemicals, or process additives, are introduced into a process stream. Corrosion inhibitors, desalter demulsifiers, neutralizers, process antifoulants, oxygen, hydrogen scavengers, caustic, and water washes are most often considered to be requiring special attention during injection point design. [1]
What is a Mixing Point?
Mix Points: Mix points or Mixing Points are points of joining of process streams of differing composition and/or temperature where additional design attention, operating limits, and/or process monitoring are utilized to avoid damage mechanisms (e.g., corrosion).
Design Precautions of Injection Devices
Injection of corrosive chemicals like caustic, and sulfuric acid can cause serious corrosion issues and it is best to be avoided, injection facilities should be designed to allow proper mixing and dilution of the injected chemical in order to avoid the concentration of chemicals on hot metal surfaces. [4]
Figure 2: Static Mixer
Figure 3: Injection Quills
Material Selection for Mixing Zone
While selecting materials for the mixing zone, consideration shall be made for local erosion, corrosion-erosion, and corrosion rates influenced by flow regime and turbulence. High corrosion-resistant alloys or internally lined injection facilities can be used based on the injected chemical, mixing facility configuration, and operating temperature.
Each lined pipe and fitting shall be provided with a venting system that will release any annular pressure between the polymer liner and the host metallic component.
NOTE —Venting is not required with PVDF, PP, ETFE, or PVDC liners.
Figure-4: PTFE Lined spool with vent holes
Injection devices
Injection device designs should include the design of piping tees, spray nozzles, quills, and/or static mixers.
Design Considerations for Quills
Quills should discharge co-currently into the center of the receiving stream to enhance dispersion and prevent contact of undiluted injectant with the pipe wall.
Quill designs shall include flow calculations to determine the natural frequency and whether fatigue is an issue.
Quills with beveled ends should be considered, as they promote better dispersion and mitigate potential corrosion or fouling caused by concentrating chemical injectant at the pressure boundary.
Considerations for Spray Nozzles
Spray nozzles should be considered for injecting liquids into gas streams or when the injectant is required to coat/wet the pipe wall. Spray nozzles are used to disperse the injectant stream.
The co-current injection is suggested when wetting is the desired result.
Cross-flow injection should be avoided because it results in impingement on the pressure boundary wall. Impingement can also occur when the injection is too close to a change in direction.
Figure-5: Injection Nozzle Discharge Orientation
Figure 6: Injection Devices
Injection into Vessels or Tanks
For injection into pressure vessels or tanks, designs that tend to concentrate corrosive media in a small area should be avoided. For example, tank inlets should be designed in such a way that the concentrated solutions are mixed and diluted when they are introduced. Otherwise, excessive corrosion can be caused by localized pockets of concentrated solutions. The poor design causes concentration and uneven mixing of incoming chemicals along the vessel wall (circled areas). Good design allows concentrated solutions to mix away from vessel walls. [3]
Figure-7: Injection to Vessels or Tanks
Temperature Difference
High-temperature differences between the injected stream can the mainstream can cause thermal shock, this shall be considered in the design of the injection nozzle to avoid direct contact of the injected stream with the metallic wall of the mainstream. Another approach can be by changing the temperature of the injected stream (heating or cooling) to approach the temperature of the mainstream.
Operational Considerations
Plant operators should understand the potential risk of the improper use of the injection points. For the operating schemes where the flow of the mainstream is not continuous, the chemical injection shall be stopped while the mainstream is flowing, then the mainstream can be stopped. And for starting chemical injection, the operator shall ensure that the mainstream is flowing before starting the chemical injection.
This can be best achieved by design through the application of interlock. Otherwise, operating procedures with a checklist shall be developed with proper protocol to avoid mistakes.
Inspection Considerations
Injection
points are sometimes subject to accelerated or localized corrosion. Those
susceptible should be treated as separate inspection circuits, and need to be
inspected thoroughly on a regular schedule. [2]
At the time of scheduled periodic inspections, extensive inspection should be applied to an area beginning 300 mm upstream of the injection nozzle and continuing for at least 10 pipe diameters downstream of the injection point. [2]
Figure-8: Typical CML locations
In the case of the use of plastic-lined pipes equipped with vent holes, in the event of a liner failure the steel housing is likely to corrode evenly within the pipe and cause a catastrophic and unannounced failure. Vent holes shall not be Plugged. If the line is insulated, extend the vent out of the cladding and include the check of leaks through the vent holes in the periodical inspection and patrolling checklist.
References
[1] NACE SP0114-2014: Refinery Injection and Process Mix Points
[2] API 570: Piping Inspection Code: In-service Inspection, Rating, Repair, and Alteration of Piping Systems
[3] ASM Metals Handbook, Volume 13 – Corrosion
[4] API 571, Damage Mechanisms Affecting Fixed Equipment in the Refining Industry
[5] [ASTM F1545 Standard Specification for Plastic-Lined Ferrous Metal Pipe, Fittings, and Flanges]
