94 Destructive testing of welds

In contrast to NDT methods, which are essentially predictive techniques, the only real way to verify the mechanical integrity of a weld is to test a piece of it to destruction. This may be performed for the purposes of the welding or for the testing of a 'test plate' - properly called a 'production control test plate'. The test plate often represents a pressure vessel longitudinal seam weld. It is tack-welded to the end of the seam preparation, welded at the same time, and then cut off and...

532 Toleranced features

Pressure vessel codes and standards are almost unanimous on which features need to be toleranced to ensure that a vessel retains its fitness for purpose. There are five basic toleranced features surface alignment - this really means 'misalignment' of the plate surfaces circumference - an accuracy measurement circularity - also known as out of roundness (OOR) profile - covering dents, bulges, or other departures from a plane or prismatic (three-dimensional) profile. These five features are used...

1111 Sources of information

When dealing with Directives, Statutory Instruments, Regulations, and similar documents, it is important that full, up-to-date information is obtained. In many cases, the definitive content is obtainable only from the full text of the Directive, Regulation, etc. Care must, therefore, be taken to obtain these from the authorized sources. The list below shows some accepted sources of reference for pressure equipment-related topics 11.11.1 Pressure system safety - general Professional advice is...

1185 PED conformity assessment procedures

Sections 11.8.5.1-11.8.5.13 contain a summary of the conformity assessment procedures and responsibilities of the parties contained in Schedule 4 of the Pressure Equipment Regulations (Annex III of the PED). Figure 11.5 reproduces the product classification table and the nine classification charts given in the PED. Refer to the Regulations themselves or Guidance notes on the UK regulations (URN 99 1147) for a full statement of the requirements. Table 1 Table 2 Table 3 Table 4 Table 5 Table 6...

413 Materials and referenced standards quick reference

*Note that many British Standards are in the process of being replaced by Appendix 3 of this book shows recent CEN TC reference may be used to find the 4.14 Pressure vessel codes - some referenced *Note that many British Standards are in the process of being replaced by European harmonized standards. Appendix 3 of this book shows current status. The CEN TC reference may be used to find the current state of development.

552 Manufacturers data report forms

ASME Section I has ten different Manufacturers' Data Report Forms (MDRFs) to cover various types of boilers and related components. These forms provide a summary of important information about the boiler (its manufacturer, purchaser, location, and identification numbers) and a concise summary of the construction details used. This includes a list of the various components (drum, heads, headers, tubes, nozzles, openings), their material, size, thickness, type, etc., and other information such as...

95 Nondestructive testing NDT techniques

Penetrant Testing Welds

NDT techniques are in common use to check the integrity of pressure equipment materials and components. The main applications are plate, forgings, castings, and welds. Close visual examination can reveal surface cracks and defects of about 0.1 mm and above (see Fig. 9.15). This is larger than the 'critical crack size' for most ferrous materials. Useful standards BS EN 970 1997 Non-destructive examination of fusion welds. BS EN 25817 1992 Arc-welded joints in steel - guidance on quality levels...

12 General technical information

Transportable pressure receptacles (gas cylinders) www.icrank.com Specsearch.htm www.nssn.org www.normas.com ASME BPVC guide.html www.pretex.com Glossary.html www.yahoo.com Business_and_Economy Companies Industrial Valves_and_Control www.highpressure.com www.flowbiz.com valve_manual.htm www.geapcs.com www.dti.gov.uk strd www.normas.com ASME BPVC qx0010.html books vganapathy boilers.html www.abb.com americas usa hrsg.htm equipment codes PTC4.4 Default.asp. www.welding.com www.cybcon.com Nthelen...

Asme A Stamp For Field Assembly Of Power Boilers

Fig. 5.4 The ASME code symbol stamps Table 5.2 ASME Section I code symbols stamps Table 5.2 ASME Section I code symbols stamps * It is possible to manufacture certain small boilers without welded joints. In * It is possible to manufacture certain small boilers without welded joints. In such cases, qualified welders, weld procedures, heat treatment facilities, and non-destructive examination would not be required. t Not required for valves whose manufacture does not involve welding. The 'S'...

43 Inspection and test plans ITPs

The use of ITPs is well accepted throughout the pressure equipment manufacturing industry. The ITP is one of the most useful working documents. Used in a key monitoring and control role, it summarizes the activities of manufacturer, contractor, and certifying or notified body (see Chapter 11). Table 4.1 shows typical technical steps included in an ITP The following guidelines should be noted when dealing with pressure vessel ITPs. Code compliance A good pressure vessel ITP will refer to the...

723 HRSG terms and definitions

Listed below is some commonly used HRSG terminology. Baffle A plate in an HRSG that directs the flow of water, gas, Removal of liquids and solids from a vessel or line by the use of a special high-pressure drop valve. An enclosed vessel (as in an HRSG) within which water is heated and circulated to produce steam. A continuous blowdown system in a boiler that controls water chemistry in all of the HRSG boiler drums by blowing water from a higher-pressure drum to a lower-pressure drum. A device...

451 PD 5500 and the Ped Esrs

In recognition of the future requirement for a UK harmonized standard for pressure vessels, PD 5500 includes information showing how its technical content complies with the essential safety requirements (ESRs) of the pressure equipment directives (PED). Table 4.5 shows an outline of these comparisons. Note, however, that as PD 5500 does not currently have formal status as a harmonized standard, compliance with its technical requirements does not carry an automatic presumption of conformity with...

Table 113 ISO technical standards for gas cylinders

Cylinders for acetylene Basic requirements. Part 1 Cylinders for acetylene Basic requirements. Part 2 Refillable seamless steel gas cylinders. Refillable welded steel gas cylinders. Cylinder valve outlets for gases and gas mixtures Selection and dimensioning. Periodic inspection and testing of seamless steel gas cylinders. Gas cylinders Precautionary labels. Valve outlets for gas cylinders List of provisions which are either standardized or in use. Gas cylinders Refillable seamless aluminium...

Table 412 Flat plates covers and flanges basic principles

Thickness t of circular flat plate is given by from UG-34 t d CP SE 1 2 d effective diameter of plate C coefficient between 1.0 and 0.33 and related to the corner design P design pressure S allowable stress at design temperature E welded joint efficiency depending on the extent of non-destructive testing used Thickness t of a non-circular flat plate is given by t d ZCP SE 1'2 Z is a factor used to compensate for lack of uniform membrane support obtained when a plate is circular. D major...

551 The role of the AI Authorized Inspector

This is a system of third party inspection to ensure that manufacturers of ASME vessels follow the ASME code rules. In the simplest situation, a boiler manufacturer and the boiler purchaser are the first two parties, and an Authorized Inspector AI is the independent third party. It is the function of the AI to verify that the manufacturer complies with the code. Who are they An AI is defined by ASME Section I PG-91 as an inspector employed by a state or municipality of the United States, a...

522 The vessel dimensional check

Practically, the dimensional check can be done either before or after the hydrostatic test see Fig. 5.1 . Any strains or distortions that do occur will be small, and difficult to detect by simple measurements methods. Dimensional checking can be done using a steel tape measure, with the use of a long steel straightedge and large inside or outside callipers for some dimensions. Dimensional tolerances for pressure vessels tend to be quite wide. There is a technical standard DIN 8570 that gives...

622Valve technical standards

Technical standards in common use for cast steel valves are valve design and shell wall thickness API 600 pressure-temperature rating ASME ANSI B16.34 face end dimensions ASME ANSI B16.10 flange dimensions ASME ANSI B16.5 and B16.47 inspection and testing API 598. The ASME ANSI standard B16.34 is a valve standard used in conjunction with the ASME codes on boilers and power piping in ASME design installations and, separately, as a valve standard in itself. The standard is relevant to flanged,...

97 NDT vessel code applications

Pressure vessel and other pressure equipment codes vary in the way that they address both the extent of NDT required and the acceptance criteria that are applied to the results. Tables 9.5 and 9.6 summarize NDT requirements given in the vessel codes covered in chapter 4. Note that these are indicative requirements only code inquiry cases may exist that can clarify or even amend these requirements. Table 9.5 NDT requirements pressure vessel codes quick reference 100 RT or UT on type A joints...

Table 43 PD 5500 Cat 1 Key points

It is unusual for boiler drums not to be specified as fully compliant with Cat 1 requirements. Remember that independent survey and certification is mandatory for full PD 5500 compliance. If 'non-specified' materials are used, do a full check on the material properties. PD 5500 Section 2 specifies the checks that are required for materials to be permissible. Check that all pressure-retaining material is positively identified and is traceable to its source. As a guide, high-alloy steels should...

Table 418 Air receivers to BS 5169 key points

BS 5169 requires that 'competent supervision' is required for class I receivers, but does not specify full independent inspection. In practice it is common for air receivers to be considered as having equivalent 'statutory status' to BS 5500 vessels, hence they are normally subject to independent survey and certification. It is rare to see any type of 'partial code compliance' specified for these air receivers. For class I receivers, BS 1449 and BS 4360 plate materials are not permitted....

Fig 114 Pressure equipment classification and conformity assessment Source DTI guidance notes on UK Pressure Equipment

Engineers' Guide to Pressure Equipment Production classifications explosive, flammable, toxic, or oxidizing Group 2 All other fluids Exceptionally, vessels intended to contain an unstable gas and falling within categories I or I on the basis of Chart 1 must be classified in category III Exceptionally, vessels intended to contain an unstable gas and falling within categories I or I on the basis of Chart 1 must be classified in category III Fig. 11.5 PED - the nine classification charts. Source...

46 The ASME vessel codes

Asme Code Section Viii

The ASME code comprises the following sections ASME Section The ASME code comprises the following sections ASME Section Rules for construction of power boilers Rules for construction of nuclear power plant components Rules for construction of heating boilers Rules for care and operation of heating boilers Rules for construction of pressure vessels Fibre-reinforced plastic pressure vessels Rules for in-service inspection of nuclear power plant components The ASME Boiler and Pressure Vessel Code,...

Table 44 PD 5500 Cat 2 Key points

As with Cat 1 vessels it is unusual for Cat 2 pressure vessels not to be specified as fully compliant with code requirements. Independent survey and certification is mandatory. PD 5500 Cat 2 vessels have limits placed on maximum plate thickness -this limits the design pressure. Material traceability requirements are the same as for Cat 1 vessels. Note that permanent weld backing-strips are allowed for Cat 2 vessels. Check that they are of the correct 'compatible' material. Alignment tolerances...

Table 42 PD 5500 a summary

Manufacturer purchaser agreement Section 1.4 places the responsibility for code compliance firmly on the manufacturer. Look at Section 1.1 - it confirms that PD 5500 applies only to vessels built under independent survey. Section 1.4 specifies that code compliance is documented by the use of 'Form X' - this is issued by the manufacturer and countersigned by The Inspecting Authority the 'third party . Table 1.5 lists approximately 50 points for separate agreement. Vessel design is covered by...

322 Safety first corrosion allowance and welded joint efficiency

Corrosion occurring over the life of a vessel is catered for by a corrosion allowance, c, the design value of which depends upon the vessel duty and the corrosiveness of its contents. As an example, a design criterion of c 1 mm is typical for air receivers in which condensation of air moisture is expected. Most vessel codes use the principle that, when dimensions in any formula refer to a corrodable surface, then the dimensions inserted into the formula are those at the end of the vessel's...

23 Pressure equipment symbols

Isa Ball Valve Symbol

Pressure equipment symbols are in regular use in schematic drawings and Process and Instrumentation Diagrams PIDs . There are many variations based on BS, ISO, and American standards. Figures 2.1-2.4 show some commonly used types. Table 2.3 and Figs 2.5 and 2.6 show symbols for typical pressure equipment-related instrumentation. Fig. 2.1 Vessel symbols. Courtesy MS Visio Covered tank Gas holder Storage sphere Gas cylinder Horizontal vessel Autoclave Fig. 2.1 Vessel symbols. Courtesy MS Visio...