SP R.20

12/31/2009Page 106 of 106

Standard Paragraphs

API CRE Subcommittee on Mechanical Equipment

REVISION 26

Sept 2008

N435 SI Units.pdf

SPECIAL NOTES

API publications necessarily address problems of a general nature. With respect to particular circumstances, local, state, and federal laws and regulations should be reviewed.

API is not undertaking to meet the duties of employers, manufacturers, or suppliers to warn and properly train and equip their employees, and others exposed, concerning health and safety risks and precautions, nor undertaking their obligations under local, state, or federal laws.

Information concerning safety and health risks and proper precautions with respect to particular materials and conditions should be obtained from the employer, the manufacturer or supplier of that material, or the material safety data sheet.

Nothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product covered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent.

Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. Sometimes a one-time extension of up to two years will be added to this review cycle. This publication will no longer be in effect five years after its publication date as an operative API standard or, where an extension has been granted, upon republication. Status of the publication can be ascertained from the API Downstream Segment [telephone (202) 682-8000]. A catalog of API publications and materials is published annually and updated quarterly by API, 1220 L Street, N.W., Washington, D.C. 20005.

This document was produced under API standardization procedures that ensure appropriate notification and participation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this standard or comments and questions concerning the procedures under which this standard was developed should be directed in writing to the general manager of the Downstream Segment, American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the general manager.

API standards are published to facilitate the broad availability of proven, sound engineering and operating practices. These standards are not intended to obviate the need for applying sound engineering judgment regarding when and where these standards should be utilized. The formulation and publication of API standards is not intended in any way to inhibit anyone from using any other practices.

Any manufacturer marking equipment or materials in conformance with the marking requirements of an API standard is solely responsible for complying with all the applicable requirements of that standard. API does not represent, warrant, or guarantee that such products do in fact conform to the applicable API standard.

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Copyright © 1999 American Petroleum Institute

FOREWORD

This standard is based on the accumulated knowledge and experience of manufacturers and users of ________. The objective of this standard is to provide a purchase specification to facilitate the procurement and manufacturer of _________ for use in petroleum, chemical, and gas industry services.

The primary purpose of this standard is to establish minimum requirements. This limitation in scope is one of charter as opposed to interest and concern.

Energy conservation is of concern and has become increasingly important in all aspects of equipment design, application, and operation. Thus innovative energy conserving approaches should be aggressively pursued by the manufacturer and the user during these steps. Alternative approaches that may result in improving energy utilization should be thoroughly investigated and brought forth. This is especially true of new equipment proposals, since the evaluation or purchase options will be based increasingly on total life costs as opposed to acquisition cost alone. Equipment manufacturers, in particular, are encouraged to suggest alternatives to those specified when such approaches achieve improved energy effectiveness and reduced total life costs without sacrifice of safety or reliability.

This standard requires the purchaser to specify certain details and features. Although it is recognized that the purchaser may desire to modify, delete, or amplify sections of this standard, it is strongly recommended that such modifications, deletions, and amplifications be made by supplementing this standard, rather than by rewriting or incorporating sections thereof into another standard.

API standards are published as an aid to procurement of standardized equipment and materials. These standards are not intended to inhibit purchasers or producers from purchasing or producing products made to other standards.

API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure the accuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any federal, state, or municipal regulation with which this publication may conflict.

Suggested revisions are invited and should be submitted to the general manager of the Downstream Segment, American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005.

IMPORTANT INFORMATION CONCERNING USE OF ASBESTOSOR ALTERNATIVE MATERIALS

Asbestos is specified or referenced for certain components of the equipment described in some API standards. It has been of extreme usefulness in minimizing fire hazards associated with petroleum processing. It has also been a universal sealing material, compatible with most refining fluid services.

Certain serious adverse health effects are associated with asbestos, among them the serious and often fatal diseases of lung cancer, asbestosis, and mesothelioma (a cancer of the chest and abdominal linings). The degree of exposure to asbestos varies with the product and the work practices involved.

Consult the most recent edition of the Occupational Safety and Health Administration (OSHA), U.S. Department of Labor, Occupational Safety and Health Standard for Asbestos, Tremolite, Anthophyllite, and Actinolite, 29 Code of Federal Regulations Section 1910.1001; the U.S. Environmental Protection Agency, National Emission Standard for Asbestos, 40 Code of Federal Regulations Sections 61.140 through 61.156; and the U.S. Environmental Protection Agency (EPA) rule on labeling requirements and phased banning of asbestos products (Sections 763.160-179).

There are currently in use and under development a number of substitute materials to replace asbestos in certain applications. Manufacturers and users are encouraged to develop and use effective substitute materials that can meet the specifications for, and operating requirements of, the equipment to which they would apply.

SAFETY AND HEALTH INFORMATION WITH RESPECT TO PARTICULAR PRODUCTS OR MATERIALS CAN BE OBTAINED FROM THE EMPLOYER, THE MANUFACTURER OR SUPPLIER OF THAT PRODUCT OR MATERIAL, OR THE MATERIAL SAFETY DATA SHEET.

Introduction

Users of this International Standard should be aware that further or differening requirements may be needed for individual applications. This International Standard is not intended to inhibit a vendor from offering, or the purchaser from accepting, alternative equipment or engineering solutions for the individual application. This may be particularly appropriate where there is innovative or developing technology. Where an alternative is offered, the vendor should identify any variations from this International Standard and provide details.

Discussion: The proposal section para 9.2.1 indicates description of alternative designs is required to be presented in the proposal.

Annex A specifies calculations for specific speed and suction specific speed.

Annex B contains schematic drawings of cooling water and lubrication systems.

Annex C specifies requirements for hydraulic power recovery turbines.

Annex D specifies requirements for standard baseplates.

Annex E contains an inspector's checklist.

Annex F specifies criteria for piping design.

Annex G give guidance on material class selection.

Annex H specifies requirements and gives guidance on materials selection.

Annex I specifies requirements for lateral analysis.

Annex J specifies requirements for determining residual unbalance.

Annex K contains seal chamber runout illustrations.

Annex L contains forms which may be used to indicate vendor drawing and data requirements.

Annex M contains forms which may be used to record test data.

Annex N contains data sheets which purchasers are encouraged to use.

Discussion: ISO requires that the Annexes are numbered sequentially as they are referenced in the text. [ ISO Directives Part 2 - 4the edition 2001, paragraph 5.2.6]. Since the next paragraph references data sheets the data sheets would appear as Annex A if the above listing was not present. Thus by prelisting the Annexes before any of the other text, the annexes are placed in the desired order. The above is an excert from API 610. Each TF should determine the order in which they want the Annexes to appear.

This International Standard requires the purchaser to specify certain details and features.

A bullet (() at the beginning of a subclause or paragraph indicates that either a decision by, or further information from, the purchaser is required. Further information should be shown on the data sheets (see example in Annex XX) or stated in the quotation request and purchase order.[ISO Comment to 619]

In this International Standard, US Customary units are included in brackets for information.

Discussion: Bullets appear when the wording " if specified”, "the purchaser shall specify" or the purchaser “should”appears in the paragraph. A bullet is not required for "unless otherwise specified" or when a decision has been previously made and the phrase "If XXXXX has been specified" is used.

“When” specified has been replaced with “If specified” since “When” is a time and “if” is in the event that. Therefore “If” is proper, not “ when”.

Discussion: Information in square brackets i.e [ XXX ] are for Task Force use and reference only.

CONTENTS

1Scope1

2Normative References1

3Definition of Terms3

4General13

4.1Unit Responsibility13

4.2Unit Conversion13

4.3Nomenclature13

5Requirements13

5.1Dimensions13

5.2Statutory Requirements14

5.3Alternative Designs14

5.4Conflicting Requirements14

6Basic Design14

6.1General14

6.2Pressure Casings (or Cylinders)20

6.3Casings (or Cylinder) Appurtenances24

6.4Pressure Casings (or Cylinder) Connections24

6.5External Forces and Moments27

6.6Rotating Elements (or Gear Elements)27

6.7Seals28

6.8Dynamics28

6.9Bearings and Bearing Housings41

6.10Lubrication48

6.11Materials56

6.12Nameplates and Rotation Arrows68

7Accessories69

7.1Drivers69

7.2Couplings and Guards71

7.3Belt Drives73

7.4Mounting Plates74

7.5Controls and Instrumentation78

7.6Piping88

7.7Special Tools94

7.8Coatings, Insulation and Jacketing94

7.9Starting Equipment94

7.10Fuel System94

8Inspection, Testing and Preparation for Shipment94

8.1General94

8.2Inspection95

8.3Testing98

8.4Preparation for Shipment105

9Vendor’s Data107

9.1General107

9.2Proposals108

9.3Contract Data110

Informative Annex

1) Discussion on Flanges

2) Discussion on Surface Finish

3) Discussion on L10 Life of rolling element bearings

4) Discussion on L10 Life for two and four bearing systems

5) Manufacturers allowableDmN vis API allowable

6) Manufacturers NDm used to determine API allowable

7) Screw Threads

8) The Inspector and the Bolts

9) EU, EU Directives, ATEX, adoption of API Standards

10A) IP vs NEMA Enclosures

10B) Comparison of NEMA 250 vs IEC 60529

11) Slipery Surfaces

12) Nodular Iron

13) Template for VDDR forms

14 NACE and Corrosion

14A) NACE Std Paragraphs

14B) ASME P No weld qualificatons

Figures

3Undamped Critical Speed Map30

Tables

1Driver Trip Speed17

6.9-1Bearing Selection47

6.9-2 Anti-Friction Bearing Limiting ndm Factors………………………………………………...

2(Reference for placement of this table only)83

3Minimum Requirements for Piping Materials91

4Maximum Severity of Defects in Castings97

E-2International Materials Standards113

Standard Paragraphs

API CRE Subcommittee on Mechanical Equipment

Discussion:1.Titles of API SOME mechanical equipment specifications that reference “refinery service” should be changed to include “service in petroleum, chemical, and gas industry services.”

Discussion: New Work Items (NWI) submitted to ISO TC 67 should read “Petroleum, Petrochemical and Natural Gas Industries – (Equipment covered). The primary difference between the ISO and SOME title is that the API title includes “Chemical” instead of “Petrochemical” and “Gas Industry services” instead of “Natural Gas”. The API title has broader application since Gas Industries can also apply to the Air Separation industry and “Chemical” is broader than “Petrochemicals”.

ISO TC 67 titles are limited to the scope of that technical committee i.e petroleum and natural gas industries. TC’s other than TC67 are “equipment” focused and are not limited to a specific industry. Thus standards not in TC 67 such as pumps, compressors, seals have the option to include only the equipment and not the industry in the title. For example ( API 682) i.e.ISO 21049 title is “Pumps- shaft sealing systems for centrifugal and rotary pumps”.

ISO titled documents which have “Petrochemical” in their title will have to be adopted back using “chemical, and gas industries”. ISO titles for standards not in TC 67 which have only the equipment or the API “petroleum, chemical, and gas industries” can be adopted without a title change. It is therefore recommended that ISO standards not in TC 67 read like the API title or not reference the industry such as the above example for ISO 21049.

TF Chairs should include the appropriate proposed title when submitting a project justification to iniate work on an API document.

2.As the result of the request to provide insight into the standard paragraphs, a discussion paragraph has been added after some of the paragraphs. Discussion paragraphs are more informal than note paragraphs and are for the guidance of the TF and are not intended for inclusion and publication in the standards. NOTE paragraphs are part of the standard.

3.During review of this issue of the SPs it has been suggested these discussion paragraphsbe included in the base specifications. The SP task Force has decided to leave it up to each task force chair to determine the extent to which he chooses to incorporate any discussion paragraphs.

1Scope

This standard covers the minimum requirements for [TF Chairmen: description or limitation on the type insert the equipment the standard covers here] for use in the petroleum, chemical, and gas industry services. [The remainder of this paragraph generally gives further definition of equipment to which the standard is to be applied]

2Normative References

Discussion: The referencing of standards in this document is presented in one of the following formats. The choice of the format depends upon the availability of similar documents:

In the following, US Ref yyyy is, for example, ASTM uuuu or API vvv.

a) Delete as many references as possible. This is normal guidance but there is still scope for some deletion in current drafts. (Refer to rewrite of SP 6.2.1 as an example with relation to the ASME code)

b) If the US reference can be replaced by the ISO reference, and all parties accept this, then use the ISO reference only. This is the desired ISO situation.

Example (from ISO 10423) “Viscosity and sand content shall be determined in accordance with ISO 10414-1.”

c) If the ISO and US references provide the same technical result for a particular provision, but it is desired to retain the traditional US reference, then write the provision in the form:

" ....... in accordance with ISO xxxxx.

NOTE - For the purposes of this provision, US Ref yyyy is equivalent to ISO xxxxx."

In this case US Ref yyyy is included as an informative reference in the bibliography.

Example “Steam turbine drivers shall be in accordance with ISO 10437

NOTE For the purposes of this provision API Std 612 is equivalent to ISO 10437."

This case will often include the case of an ISO standard based on an API where the ISO has not yet been adopted back by API.

The note shall be placed in the line following each subclause/clause in which this formulation is used to state a provision. If this could be ambiguous, for example because the subclause/clause contains several such provisions, then the note shall be placed in the line following the sentence containing the provision.

SPTF GUIDANCE FOR API TF CHAIRS AND CONVENORS: This (c) approach should only be used if the ISO standard is IDENTICAL to the US or API standard. The “same technical result” wording is subjective and subject to interpretation, therefore the majority, if not all, dual references should appear as outlined in item d) following.

d) If the ISO and US reference do not provide the same technical result for a particular provision, BUT both results are acceptable then write the provision in the form:

" ....... in accordance with ISO xxxxx or US Ref zzzz".

In this case both the ISO xxx and US Ref zzzz are normative references (if the provision is a requirement), or informative references (if the provision is a recommendation or permission).

Example (from ISO 10439) “The compressor shall be performance tested in accordance with ISO 5389 or ASME PTC 10.”

In the above example, the manufacturer is free to choose which of the referenced standards to apply. If it is considered necessary for the purchaser to select one or other of the referenced standards, the provision should be constructed as follows: “The compressor shall be performance tested in accordance with ISO 5389 or ASME PTC 10, as specified.”

The SP’s referencing of standards requires the purchaser to choose what reference specifications are to be used and takes the form of the previous sentenance . It is recommended that the specifications particular to a standard and not covered by the SP’s be referenced in this mannor.

e) If an ISO Standard is not available but other internationally recognized similar standards are available, the wording used is internationally recognized standard. Refer to 6.11.1.2, for example, materials shall be identified by reference to applicable internationally recognized standards, or 6.11.2.5 Nodular iron castings shall be produced in accordance with internationally recognized standards such as ASTM A396. Not covered by the above ISO a,b,c,d therefore this guidance is still applicable.

f). If there are no other internationally recognized standards, the reference is presented as is presently in R22. as in 6.6.1 “These areas shall be properly demagnetized to the levels specified in API Standard 670... Not covered by the above ISO a,b,c,d therefore this guidance is still applicable.

g) Even if there is a ISO document available but the TF feels it not appropriate, the ISO reference does not have to be included in the document. (Per TC 67 procedures xxxxx).

h) Only reference published standards; this differs somewhat from ISO which allows referencing a document if it is in the FDIS stage. Referencing a standard before it is published is in conflict with SP2.5 therefore, only published standards should be referenced.

i) When the ASME code has been referenced in the SP the reference took one of the following three option:

a. Design (stress levels, etc.) (Refer to SP 6.2.1 as an example)

b. NDE, welder qualification, etc.(Refer to SP 6.11.4)

c. Buy-outs, other pressure vessels (pulsation dampers, coolers, etc.)

In the first category, (a) pull the paragraph out of the applicable code reference and include in the clause without reference to the specific standard. This agrees with ISO a) above. Refer to the rewrite of SP 6.2.1

For the second category, (b) Default to the ASME code and with purchasers approval allow EN 287 and 288. (Refer to rewrite of SP 6.11.4)

For the third category, (c) use the term “shall be in accordance with Section VIII of ASME pressure vessel code or other purchaser specified pressure design code”. This will be a bulleted item and included on the datasheet. [API 614]

Discussion: This paragraph previously did not have a default. It was modified to provide a default . The default is the the ASME code which is generally specified anyway. (90-10 rule)

2.1 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 10241:1992 , International terminology standards-Preparation and layout

ISO Directives Part 2:2001, Rules for the structure and drafting of International Standards

ISO Directives Part 3:1997, Rules for the structure and drafting of International Standards

ISO 6708:1995, Pipework components – Definition and selection of DN (nominal size)

ISO 7268:1983, Pipe components – Definition of nominal pressure

ISO 3740:2000, Acoustics – Determination of sound power levels of noise sources-Guidelines for the use of basic standards

ISO 3744:1994, Acoustics – Determination of sound power levels of noise sources using sound pressure –Engineering method in an essentially free field over a reflecting plane

ISO 3746:1995, Determination of sound power levels of noise sources using sound pressure –Survey method using n enveloping measurement surface over a reflecting plane – Technical Corrigendum 1

ISO 10494:1993, Gas turbine sets-Measurement of emitted airborne noise-Engineering/survey method

ISO 261: 1998, ISO general purpose metric screw threads-General plan

ISO 262: 1998, ISO general purpose metric screw threads-Selected sizes for screw,bolts and nuts

ISO 724: 1993, ISO general-purpose metric screw threads-Basic dimensions

ISO 965: 1998, 1-5, ISO general purpose metric screw threads-Tolerances

ISO 7- l:1994, Pipe threads where pressure-tight joints are made on the threads

ISO 7-2: 2000, Pipe threads where pressure-tight joints are made on the threads-Verification by means of limit gauges

ISO 7005-1:1992, Metallic flanges – Steel flanges

ISO 7005-2:1988, Metallic flanges – Cast iron flanges

ISO 582:1995, Rolliing bearings – Chamfer dimensions – Maximum values

ISO 8821:1989, Mechanical vibration- Balancing-Shaft and fitment key convention

ISO 3448:1992, Industrial liquid lubricants – ISO viscosity classification

ISO 8068:1987, Petrolium products and lubricants – Petroleum lubricating oils for turbines (categories ISO-L-TSA and ISO-L-TGA)-Specifications

ISO 281:1990, Rolling bearings-Dynamic load ratings and rating life. TF Chair note:(This is not the latest issue of this standard, however theSPTF has reviewed the later edition and elected to continue referencing the first edition)

ISO 355:1977, Rolling bearings-Metric tapered roller bearings-Boundary dimensions and series designations

ISO 15;1998, Rolling bearings-Radial bearings-Boundary dimensions, general plan

ISO 464:1995, Rolling bearings-Radial bearings with locating snap rings-Dimensions and tolerances

ISO 492:2002, Rolling bearings-Radial bearings-Tolerances

ISO 582:1995, Rolling bearings-Chamfer dimensions-Maximum values

ISO 5753:1991, Rolling bearings-Radial internal clearances

ISO 8443:1999, Rolliing bearings-Radial ball bearings with flanged outer ring-Flange dimensions

ISO 12043:1995, Rolling bearings-Singel-row cylindrical roller bearings-Chamfer dimensions for loose rib and non-rib sides

ISO 12044:1995, Rolling bearings-Single-row angular contact ball bearings-Chamfer dimensions for oouter ring non-thrust side

ISO 286-Part 1:1988, ISO system of limits and fits-Basis of tolerance, deviations and fits

ISO 286-Part 2:1988, ISO system of limits and fits-Tables of standard tolerance grades and limit deviations for holes and shafts

ISO 3290:2001, Rolling bearings-Balls-Dimensions and tolerances

SPTF NOTE: The above lising of standards is complete for the ISO references upto and including SP 6.9. Need to add references for later paragraphs onces these later paragraphs have been reviewed. In addition, need to add US Customary references.

SPTF: Look into the rules for adding standards to this reference list. Our interpretation is that if its not referenced in the document, it can not be included in these lists. KIPA inserted a reference specification to this list (GP CPLGS) which was not referenced in the document.

Note to Task Force Chairmen:

1) All standards referenced in the SP’s have been referenced in a normative manor and will eventually be all listed in Clause 2.

2) Additional standards applicable for each standard should be referenced in a normative mannor and also included in Clause 2.

3) If the task force references standards in an informative mannor, these shall be listed in a Bibliography. Wording “such as” preceeding a specification, makes it an informative reference. For example, 6.11.1.15 only requires the bolting to be carbon steel and the ASTM grade is not listed since the wording “such as” precedes the material spec. TF ‘s should realize that informative reference DO NOT MANDATE ANYTHING. It is suggested that all references to the extent possible, be Normative.

4) Notes following a paragraph are informative therefore you can not specify a requirement in a note.

5) Only those standards referenced in the specifications are to be included in the listing of specifications in Section 2. [ISO Directives Part 2, 6.2.2]

2.2 For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

Discussion: Undated references may be made only to a complete document or a part thereof and only in the following cases:

a) it is accepted that it will be possible to use all future changes of the referenced document for the purposes of the referring document

b) for informative references.

Undated references shall be understood to include all amendments to and revisions of the referenced document. [ISO Directives Part 2: 2001 , 6.6.7.5.2]

• 2.3 The hierarchy of documents shall be specified.

NOTE - Typical documents are user, industry, ISO and API specifications, data sheets , meeting notes and supplemental agreements.

3Terms and definitions

For the purposes of this document, the following terms and definitions apply. [ISO Directive Part 2: 2001 Para 6.3.1]

Note to Task Force Chairmen:

1) The following list of definitions is not necessarily complete or applicable to all standards. They should be amended and/or supplemented as appropriate for each standard.

2) New definitions should follow the format of these SP’s. ISO 10241: 1992 and ISO Directive Part 2: 2001 Annex C cover the rules for definitions. The requirements in these ISO documents which are applicable to the standard paragraphs are outlined below for easy reference.

3) The information in square brackets [ ] is the ISO paragraph containing the requirement,

TERM (word or words) being defined

The term to be defined should be bold and in lower case [ISO 10241:1992 paragraph 6.2.2]

If more than one preferred term is seleced, they shall each be printed in boldface on a separate line . [ISO 10241:1992 paragraph 6.2.2.] (Refer to the definition of Normally Open, Normally closed, SP 3.34, 3.35, 3.36 for an example of this formatting requirement)

If a given term designates more than one concept, each concept shall be treated in a separate entry. [ISO 10241:1992 paragraph 6.2.2.] (Refer to the definition of Normally Open, Normally closed, SP 3.34, 3.35, 3.36 for an example of this formatting requirement)

When a term is used to represent several concepts as indicated in the previous paragraph, the subject to which each concept belongs is indicated between angle brackets, before the definition. [ISO 10241:1992 paragraph 6.2.10 & ISO Directives Part 2 : 2001 Paragraph C 3.6] (Refer to the definition of Normally Open, Normally closed, SP 3.34, 3.35, 3.36 for an example of this formatting requirement)

If there is a synonym for the term being defined, each shall be placed on a new line after the initial term. [ISO Directives Part 2 : 2001 paragraph C 3.3] (Refer to the definition of supplier and vendor, SP 3.75 for an example of this formatting requirement)

definition

Definitions shall consist of a single phrase describing the term being defined. [ISO 10241:1992 paragraph 6.2.11] (Refer to Axially split joint SP 3.3 for an example of this formatting requirement)

Definitons should not contain a requirement [ISO Directive Part 2:2001 Paragraph C.1.5.2]

There shall be no punctuation (period, semi-colon, etc) at the end of a definition. [ISO Directive Part 2: 2001 Paragraph C 3.2 & ISO 10241:1992 paragraph 6.2.11]

The definition shall not begin with an article unless there is a specific reason, [ISO 10241:1992 paragraph 5.2.5.d ]

Definition shall not begin with a capital letter (except for proper nouns and the like).[ ISO 10241:1992 paragraph 6.2.11]

The term being defined should not appear in the definition [ISO 10241:1992 paragraph 6.2.10]

If a definition has been taken verbatim from another normative document, a reference shall be added between square brackets after the definition ISO 10241:1992 paragraph 6.2.11] (Refer to PN SP 3.44 for an example of this formatting requirement)

If a definition has been adapted and modified from another document, an explanation shall be given in a note. [ISO 10241:1992 paragraph 6.2.11] (Refer to NPS SP 3.36 for an example of this formatting requirement)

References to related definition – On a separate line after the definition insert the term cf (Cross reference) and the term and paragraph number [ISO 10241:1992 paragraph 6.2.13.2] (Refer to 3.2 definiton of Anchor bolts as an example of this formatting requirement).

If a term is used to represent several consepts, the subject field to which each consept belongs shall be indicated between angle brackets, before the definition. [ISO directives Part 2 : 2001 Para C 3.6] (Refer to definition of “local” SP 3.17 for an example of this formatting requirement)

If a given term designates more than one concept, each consept shall be treated in a separate definition entry. [ISO Directives Part 2; 2001 C.3.2 ] (Refer to definition of Normally open SP 3.34, 3.35, 3.36 for an example of this formatting requirement)

If more than one term to be defined is selected, they shall each be printed in boldface on a separate line. [[ISO 10241:1992 paragraph 6.2.2. (Refer to definition of Normally open SP 3.34, 3.35, 3.36 for an example of this formatting requirement)

No units shall be used in the definition of a term [[ISO 10241:1992 paragraph 5.2.5.e] (Refer to definition of Long wave cut-off SP 3.52 for an example of this formatting requirement)

The definition shall have the same grammatical form as the term. Thus to define a verb phrase shall be used; to define a singular noun, the singular shall be used. [ISO 10241:1992 paragraph 5.2.5.a] (Refer to definition of Radially split joint SP 3.51for an example of this formatting requirement)

Parenthese and square brackets shall be used only if they constitute a normal written form of the term. They shall not be used to show alternative terms [ISO 10241:1992 paragraph 6.2.2]

“must” vs “shall” - “Do not use “must” as an alternative for “shall”. [ISO Directives Part 3:1997 Annex E table E.1 and ISO Directives Part 2 Annex G ] (Refer to the SP 5.1 modifications of “Statutory Requirement” as an example of this ISO formatting requirement)

NOTES after the definition

Notes may be added to a definion after the definition. The term NOTE shall be capatilized followed by a dash. A note shall be on a separate line in smaller type and should have the following format:

NOTE – Insert here the note. [ISO 10241:1992 paragraph 6.2.15]( Refer to 3.10 gauge board as an example of this formatting requirement).

When several notes occur within the same clause, they shall be designated “NOTE 1”, “NOTE 2”, NOTE 3”, etc. and placed on separate lines.

Can’t state a requirement in a NOTE. NOTES are intended to give additional information to assist in the understanding or use of the document. [ISO Directives Part 2: 2001 paragraph 6.5.1] (Refer to SP XXX as an example of this formatting requirement).

“May & Can” The use of the word “may” is not appropriate for use in a NOTE since it implies “permission” to perform a requirement, and requirements are not allowed in a NOTE. The use of the word “can” is used to indicate a possibility and is therefore not a requirement and is appropriately used in a NOTE. [ISO Directives Part 2 Annex G paragraph G.3].. Have not “muddied the water” by introducing “Might”

When EXAMPLES and NOTES are provided after a definition, EXAMPLE comes first and the NOTE is placed below the EXAMPLE on a separate line.[ISO Directives Part 2: 2001 paragraph C.3.9] (Refer to NPS SP 3.36 as an example of this formatting requirement)

Abbreviations

Abbreviations – An abbreviation may be listed before or after the term the abbreviation refers to, depending on which is the preferred term. The abbreviation is on a separate line and in lower or upper case in accordance with the normal usage. Periods are used in accordance with normal usage. [ISO 10241:1992 paragraph 6.2.5] (Refer to 3.36 NPS as an example of this formatting requirement)

Cross Referencing

When referring to another definition the cross referenced definition shall be inserted following the definition. The cross reference should be in boldface type preceded by the small letters “cf.” and followed by the cross referenced paragraph in parenthese. [ISO 10241:1992 paragraph 6.2.13.2] (Refer to Anchor bolt SP 3.2 as an example of this formatting requirement) [ cf. is from latin Conferre which means confer or compare]

EXAMPLES OF TERM USAGE

An example of the defined term may be given in a separate paragraph . The term EXAMPLE shall be capitalized followed by a dash line. The example shall be on a separate line in smaller type and should have the following format:

EXAMPLE – Insert here an example of the defined term. [ISO 10241:1992 paragraph 6.2.14] (Refer to 3.36 NPS as an example of this formatting requirement)

When EXAMPLES and NOTES are provided after a definition, EXAMPLE comes first and the NOTE.[ISO Directives Part 2: 2001 C.3.9] (Refer to NPS SP 3.36 as an example of this formatting requirement)

3.1

alarm point

preset value of a measured parameter at which an alarm is activated to warn of a condition that requires corrective action

Discussion: All alarm points have to be measured however all measured points do not have to be alarmed.

3.2

alloy steel

steel with the maximum range given for the content of alloying elements which exceeds one or more of the following: manganese, 1.65%; silicon, 0.60%: copper, 0.60%; or in which a definite minimum quantity of any of the following alloys are specified or required within the limits of the recognized field of constructional alloy steels: aliminum, boron, chromium up to 3.99%, cobalt, columbium, molybdium, nickel, titanium, tungsten, vanadium, zirconium, or any other alloying element added to obtain a desired alloying effect [Metals Handbook???]

3.2

anchor bolts

bolts used to attach the equipment to the support structure (concrete foundation or steel structure)

cf. hold-down bolt (3.12) [format per ISO 10241:1992 6.2.13.2][cf means cross reference]

3.3

axially split joint

joint split with the principal face parallel to the shaft centerline [Formatted in accordance with ISO 10241 : 1992 5.2.5.a]

3.4

BWG

Birmingham wire gauge

standard series of sizes arbitrarily indicated by numbers, used in specifying and describing the thickness of sheet metal [format per ISO 10241: 1992 6.2.5]

Discussion: The term “wire gage” is used in describing the diameter of wire and the thickness of sheet metal. Within the SP it is used to describe the thickness of tubes in coolers. In the world of wire gages, the only consistency is that there is no consistency. There are many different standards for wire gauges, as in different countries, or for different kinds of metal, the Birmingham wire gauges and the American wire gauge being often used and designated by the abbreviations B. W. G. and A. W. G. respectively. Other wire gages are the Washburn & Moen, Imperial Standard (S.W.G), Stubs and the Brown & Sharpe.

There's a difference between gauge thicknesses of steel tubing and nonferrous tubes. The wall thickness of an 18 gauge aluminum bronze tube is 0 .0403 inch, and an 18 gauge steel tube, is 0 .049 inch.

Nonferrous alloys, copper base, and aluminum, use Brown & Sharp measurements, and steel uses Birmingham-Wire Gage (B.W.G.). However B.W.G. is used to describe the tube thickness of a copper/zinc/tin non-ferrous material such as UNS C44300 (ASTM B-111) (inhibited admiralty) in the SP’s. As a result, 18 gauge BWG measures 0 .049 inch. Brown & Sharp is 0 .0403 inch and the sheet steel manufacturing standard for 18 gauge is 0 .0478 inch. All of which differ from wire gauge dimensions.

Discussion: ISO 10241 paragraph 6.2.5 allows an abbreviation to be before or after the word to be defined depending on which on is the preferred term. It is more common to refer to B.W.G. than Birmingham wire gauge and therefore the definition in the SP will have B.W.G on the first line and Birmingham wire gauge on the second.

3.5

certified point

point to which the performance tolerances will be applied

Note: this is usually the normal operating point and the vendor will normally require that this point is within the preferred selection range.

3.6

commercial fastener

fastener manufactured to published consensus standards and stocked by manufacturers or distributors. [ASME B 18.12 :2001]

3.7

critical speed

shaft rotational speed at which the rotor-bearing-support system is in a state of resonance

3.8

DN

diamétre nominal

alphanumeric designation of size for components of a pipework system

EXAMPLE- DN20

NOTE 1 Adapted from ISO 6708:1995

NOTE 2 The letters DN are followed by a dimensionless whole number which is indirectly related to the physical size, in millimeters, of the bore or outside diameter of the end connection

NOTE 3 The number following the letters DN does not represent a measurable value

NOTE 4 In those standards which use the DN designation system, any relationship between DN and component dimensions should be given, e.g. DN/OD or DN/ID. [ISO 6708:1995 (E)]

 Discussion: The following table lists the corresponding  DN and NPS pipe sizes. TF chairmen should use this table in referencing these two systems of pipe size designations in their standards when including paragraphs not already covered by the SP's.

 

 

 

Diameter Nominal- DN -(mm)

Nominal Pipe Size- NPS -(inches)

6

1/8

8

¼

10

3/8

15

½

20

¾

25

1

32

1 ¼

40

1 ½

50

2

65

2 ½

80

3

100

4

150

6

200

8

250

10

300

12

350

14

400

16

450

18

500

20

550

22

600

24

650

26

700

28

750

30

800

32

900

36

1 000

40

1 100

42

1 200

48

1 400

54

1 500

60

1 600

64

1 800

72

2 000

80

2 200

88

 

3.9

design

manufacturer’s calculated parameter

NOTE A term used by the equipment manufacturer to describe various parameters such as design power, design pressure, design temperature, or design speed. It is not intended for the purchaser to use this term. [Formated per ISO 10241: 1992, 6.2.11 & ISO Directive Part 2: 2001 C.1.5.2]

Discussion: The term design had been used loosely by the users to describe operating conditions such as the design point. It can also apply to the equipment. In an attempt to reduce confusion, the word DESIGN has been relegated to use by the manufacturer.

3.10

fail safe

system or component which will cause the equipment to revert to a permanently safe condition (shutdown and/or depressurized) in the event of a component failure or failure of the energy supply to the system [API 614]

Discussion : SPTF eliminated the definition for flammable since NFPA definition does not cover gases. In addition, the NFPA definition of flammable only covers liquids with flash points less than 100 F. We would have to add the definition of “combustable” since the NFPA definition of combustable covers liquids with flash points greater than 100 F.

With out “Flammable” defined in the standard, one has to rely on the definition in Websters which states : “capable of being easily ignited and of burning quickly”. This definition covers liquids and gases.

The information from NFPA 30 and a discussion on “Flammable” and “Combustable” is presented below:

flammable fluid any liquid that has a closed-cup flash point at or below 37.8 ºC (100 º F) as determined by the test procedures and apparatus in paragraph 1.7.4 of NFPA 30:2003

NOTE - Adapted from NFPA 30:2003 [Format per ISO 10241: 1992 paragraph 6.2.11]

NFPA differentiates between flammable fluid and combustable fluid and also defines, liquid, flash point and what tests, depending on the fluids viscosity, to use to determine the closed-cup flash point.

Flammable fluids are easier to ignite than combustable fluids since the flash point of the flammable fluid is lower tha the combustable fluid.

Flash points are deterined experimentally by heating the liquid in a container and then introducing a small flame just above the liquid surface. The temperature at which there is a flash/ignition is recorded as the flash point.

Two general methods are called closed-cup and open-cup. The closed cup method prevents vapors from escaping and therefore usually results in a flash point that is a few degreed lower than in an open cup. Because the two methods give different results, one must always list the testing method when listing the flash point. Example: 100 oC (Closed cup)

[MSDS Hyper Glosery http://www.ilpi.com/msds/ref/flashpoint.html]

A combustable liquid is one with the closed cup flash point ABOVE 37.8 ºC (100 º F) and further subdivides these fluids into 3 subcatagories. [NFPA 30:2003 paragraph 1.7.3.1]

Liquid is defined as any material that has a fluidity greater than that of 300 penetration asphalt when tested in accordance with ASTM D 5, Standard Method of Test for Penetration of Bituminous Materials. [NFPA 30:2003 paragraph 1.7.2.3]

Flash point is defined as the minimum temperature of a liquid at which sufficient vapor is given off to form an ignitable mixture with the air, near the surface of the the liquid or within the vessel used as determined by the appropriate test procedure and apparatus specified in paragraph 1.7.4 of NFPA 30:2003. [NFPA 30:2003 paragraph 1.7.2.2]

Determination of Flash Point is based on the viscosity of the liquid and are separated into two sub-categories. The flash points testing procedures referenced are ASTM D 56, ASTM D 93, ASTM D 3278, or ASTM D 3828. All these referenced procedures are closed cup procedures.

3.11

gauge board

bracket or plate used to support and display gauges, switches and other instruments

cf. panel (3.34) [format per ISO 10241 6.2.13.2][cf means cross reference]

NOTE A gauge board is not a panel. A gauge board is open and not enclosed. A panel is an enclosure.

3.12

general purpose application

application that is usually spared or is in non-critical service

3.13

heat rate

energy consumption of a prime mover per unit of output work

Discussion: Heat rate is a general term and other terms such as steam rate may be used on individual classes of equipment. For combustion engines or gas turbines, the heat rate is calculated on the basis of the lower heating value of the fuel.

API 616 “Gas Turbines” task force recommended these modifications based on the fact that the exact heating value of the fuel is unknown. It will be somewhere between the LHV and the HHV.

The steps in the design of the equipment are:

a.Assume efficiency

b.Test the machine

c.Now need to decide what the heating value of the input fuel is. The efficiency calculated depends on the value chosen. If the HHV is used a different efficiency will be calculated than if the LHV is used. The purpose of the definition is to specify which heating value is to be used. By not introducing any units i.e. BTU per KW or BTU per HP the definition is nondimensionalized.

3.14

hold down bolts

mounting bolts

bolts holding the equipment to the mounting plate [format per ISO Directives Part 2: 2001, C 3.3]

Discussion: Hold down bolting is used to attach the equipment to the mounting plate. Anchor bolting is used to attach the mounting plate to the support structure (concrete foundation or steel structure). Refer to Paragraph 3.2 for definition of anchor bolts.

3.15

hydrodynamic bearings

bearings that use the principles of hydrodynamic lubrication

NOTE The bearing surfaces are oriented so that relative motion forms an oil wedge, or wedges, to support the load without shaft-to‑bearing contact. [ISO made 2ed sentenance a note]

Discussion: SHAFT addresses thrust collars in addition to journals. WEDGES was added to describe the action of multiple dam bearings and thrust bearings.

3.16

informative

information only

cf. normative (3.35)

NOTE An informative reference or Annex provides advisory or explanatory information. It is intended to assist the understanding or use of the document

Discussion: Appendices which are required are titled NORMATIVE. Refer to 1.5.30 for the definition of normative. Appendices which are for information are to be titled informative.

Since notes are informative, requirements, instructions, or recommendations, are NOT TO BE INCLUDED in notes. Rule of thumb – You should be able to delete a note and not affect the documents requirements.

Refer to paragraph 2 for discussion on normative reference.

3.17

inlet volume flow

flow rate expressed in volume flow units at the conditions of pressure, temperature, compressibility and gas composition, including moisture content, at the compressor inlet flange

NOTE Inlet volume flow is a specific example of Actual Volume Flow. Actual volume flow is the volume flow at any particular location such as interstage, impeller inlet, discharge or compressor discharge. Actual volume flow should not be used interchangeably therefore with inlet volume flow.

3.18

local

on or near the equipment or console [ ISO Directives Part 2 : 2001,Para C 3.6]

Discussion: The term “local” is used in multiple different contexts in the document (e.g. SP 6.1.11 “local codes”, SP 7.5.6.3 “local temperature”. ISO directives Part 2 :2001, Para C 3.6 states: “if a term is used to represent several consepts, the subject field to which each consept belongs shall be indicated between angle brackets, before the definition.

Use CAN when it CAN be replaced by the phrase “There is a possibility of”

Use MAY when May can be replaced by the phrase “It is permissible to”

3.19

maximum allowable speed

highest speed at which the manufacturer's design will permit continuous operation

NOTE The maximum allowable speed is usually set by rotor stress values.

Discussion: Revolutions per minute was removed from the definition since it is not necessary to apply units to revolutions.

Discussion: The maximum allowable speed and the maximum continuous speed differ in that the maximum continuous speed is with the specified fluid and the maximum allowable speed does not depend on the specified operating conditions.

The maximum allowable speed could be at a much higher speed than required for the specified fluid. For example, a compressor compressing a heavy molecular weight gas may be running at a much lower speed for aerodynamic reasons (high mach number) than dictated by impeller stresses.

3.20

maximum allowable temperature

maximum continuous temperature for which the manufacturer has designed the equipment (or any part to which the term is referred) when handling the specified fluid at the specified maximum operating pressure

Discussion: The maximum allowable temperature is usually set by material considerations. This may be the material of the casing or a temperature limit imposed by a gasket or O-ring.

The material strength i.e. yield point, or ultimate strength is temperature dependent. A components stress level can depend on operating pressure. Thus the margin between the strength limit of the material and the operating stresses depends on both the materials operating temperature and the components stress level. If the temperature is lowered, the materials strength increases and the stress level of the component may increase. This is the reason for associating the maximum allowable temperature to the maximum specified operating pressure.

3.19

maximum allowable working pressure

maximum continuous pressure for which the manufacturer has designed the equipment (or any part to which the term is referred) when handling the specified fluid at the specified maximum operating temperature

Discussion: Refer to the discussion on maximum allowable temperature 3.18.

3.20

maximum continuous speed

highest rotational speed (revolutions per minute) at which the machine, as built and tested, is capable of continuous operation. [API 671][617]

Discussion: The definition of maximum continuous speed was added since it did not exist previously.

The margin over design speed was moved to Section 2 since it is a specified requirement and not a definition.

All new machines are mechanically tested in the vendors shop. For rerated machines it may be in a full speed balance bunker or in the field.

3.21

maximum discharge pressure (of a centrifugal pump or compressor)

maximum suction pressure plus the maximum differential pressure the pump (or compressor) is able to develop, when operating with the furnished impeller(s) and the fluid with the maximum density [API 614]

NOTE Refer to 3.24 for the definition of maximum suction pressure..

Discussion: Operation above maximum continuous speed should be considered as a short term transient.

3.22

maximum exhaust casing pressure (of a turbine)

highest exhaust pressure that the purchaser requires the casing to contain, with motive fluid supplied at maximum inlet conditions..

NOTE The turbine casing will be subjected to the maximum temperature and pressure under these conditions.

Discussion: This is a maximum condition. Transients above this are not allowed.

This is not a performance criteria but a structural criteria. It depends on the application.

This term is traditionally used for steam turbines.

Although this term is defined in NEMA, it is good for other types of equipment besides steam turbines and may be modified by individual task forces to reflect the equipment their standards address. These terms also appear on the data sheets.

3.23

maximum exhaust pressure

highest exhaust pressure at which the turbine is required to operate continuously

Discussion: The maximum exhaust pressure for steam turbines, is a requirement determined by site steam conditions, it is set by the purchaser.

Cooling in some Gas Turbine bearings depends on the turbines backpressure. In supplemental firing operation, high backpressures can be developed.

3.24

maximum inlet pressure and temperature

highest inlet pressure and temperature conditions at which the turbine is required to operate continuously

Discussion: This term is generally applicable to general and special purpose turbines.

3.25

maximum sealing pressure

highest pressure the seals are required to seal during any specified static or operating condition and during start‑up and shutdown

Discussion: In determining this pressure, consideration should be given to the maximum suction pressure (refer to 3.24), buffer gas or flush fluid, and the effect of any internal clearance changes.

3.26

maximum suction pressure (of a pump or compressor)

highest suction pressure the pump or compressor will be subject to in service

Discussion: The maximum suction pressure may be determined by 1) Relief valve setting on the suction system 2) Maximum liquid level in a pump suction system 3) Maximum shutoff supply pressure from a suction booster pump 4) settling out pressure 5) leaking discharge check valve on parallel operating compressors or pumps.

3.27

minimum allowable speed

lowest speed (revolutions per minute) at which the manufacturer's design will permit continuous operation.

Discussion: Minimum allowable speed can be set by many factors. These may include but not limited to the following: location of critical speeds (lateral and torsional), blade natural frequencies, minimum differentials which need to be developed across close clearances for lubrication, cooling and rotor dynamic damping & stiffening, dry gas seal lift off, and minimum speed of shaft driven lubricating pumps..

3.28

minimum allowable temperature

lowest temperature for which the manufacturer has designed the equipment (or any part to which the term is referred).

Discussion: The modifier CONTINUOUS has not been applied to this definition since brittle fracture can occur during a short time the component may be at the low temperature.

Minimum temperature can be caused by operating conditions including autorefrigeration, low ambients during shipping, installation, operation or shutdowns.

3.29

minimum exhaust pressure

lowest exhaust pressure at which the turbine is required to operate continuously

Discussion: Minimum exhaust pressure is one of the factors that can determine the maximum power a turbine can develop and may be specified by the purchaser, however, for a condensing turbine, it may be set by the turbine design considering such as velocity across the last stage blades when the condenser cooling water is cold.

3.30

minimum inlet steam pressure and temperature (of a steam turbine)

lowest inlet steam pressure and temperature conditions at which the turbine is required to operate continuously

Discussion: Minimum inlet steam pressure and temperature are used to determine the turbines performance. This data is supplied by the purchaser and API 611 and 612 require the turbine to develop the required power with the minimum inlet and maximum exhaust conditions.

3.31

mounting plate

device used to attach equipment to floundations this is either a baseplate(s) or soleplates [API 687][617] Consider modifying per 2ed 686.

Discussion: “Concrete” deleted so definition can apply to offshore platforms

3.32

normal operating point

point at which usual operation is expected and optimum efficiency is desired. This point is usually the point at which the vendor certifies that performance is within the tolerances stated in this standard

Discussion: This is the point which the purchaser usually economically evaluates the offerings. The vendor usually tries to select the machine such that it has its maximum efficiency at this point.

The certified performance is usually some measure of energy consumption. For Centrifugal compressors it is power, for Gas turbines it is heat rate, for steam turbines it is steam rate.

3.33

normally open

normally closed [definition format per ISO Directives Part 2 C. 3.6]

state of a device (e.g. automatically activated switch or actuated valve).

NOTE 1 The following table gives examples of various devices and there on-the-shelf state.

Device

On-the-shelf state

electrically activated devices

deenergized position of the device.

automatically activated pressure switch

state of the contacts at ambient pressure

flow switch

state of the contacts at no flow

level switch

state of the contacts at no level

limit switch

state of the contacts at non- actuated condition

speed switch

state of the contacts at 0 rpm

NOTE 2 - During operation of the equipment, these devices may be normally energized or actuated, therefore, the state of these devices during operation may not be the same as their on-the-shelf state.

Discussion : An example of the NOTE may be illustrated by a steam turbine trip solenoid in a fail safe system.

For this case, the trip solenoid’s on-the-shelf state would be normally open.

During operation, the solenoid is energized, holding it in the closed position.

When a trip is initiated, the solenoid becomes deenergized (i.e. fail safe system), reverting to its on-the-shelf, open position, dumping the oil, shutting down the turbine.

Thus during normal operation (e.g. energized) its state (closed) is not the same as its on-the-shelf state (open).

3.34

normally open

normally closed

deenergized or non activated state of a device (e.g. automatically activated switch or actuated valve).

NOTE 1 The installed state of these devices is the same as that described in Note 1 of 3.34

NOTE 2 During operation of the equipment, these devices may be normally energized or actuated, therefore, the state of these devices during operation may not be the same as their on-the-shelf state.

NOTE 3 The normal convention in wiring diagrams is to indicate the contact state in the on-the-shelf condition.

NOTE 4 The normal convention in Process and Instrumentation Diagrams ( P&ID’S) is to identify the device in its normal operating condition and does not identify the state of the contacts.

3.35

normally open

normally closed

state during normal operation.

Discussion: The definition of a manual hand valve was added since manual hand valves are not covered in 3.34 & 3.35 and the position of a manual hand valve is whatever it is during normal operation. It has nothing to do with on-the-shelf condition.

3.36

normative

required

cf. informative (3.15)

NOTE - A normative reference or Annex enumerates a requirement or mandate of the specification.

Discussion: This term is applied in the standard to certain Appendices. Although it has been stated many times in meetings that the information in the Appendices is not part of the standard nowhere in the standards is this stated. For this reason, the term normative is introduced.

3.37

NPS

nominal pipe sizedimensionless value approximately equal to the diameter in inches

EXAMPLE- NPS 3/4

Note 1 Adapted from ASME B 31.3-2002, para. 300.2.

Note 2 The letters NPS are followed by a dimensionless number which is related to the physical size, in inches of the bore or outside diameter of the pipe.

NOTE 3 The number following the letters NPS does not represent a measurable value (Can’t specify in a note)

NOTE 4 NPS is a designation of pipe size only. The pipe end may be threaded or prepared for a welded fitting.

Discussion;

1. Up to and including 12 in diameter piping, the bore is the nominal dimension of the pipe, above 12 in pipe, the OD is the nominal dimension of the pipe.

2. The thickness of the pipe is determined by specifying the pipe schedule.

3.38

NPT

American National Standard Pipe Taper

thread form designation for pipe threads

EXAMPLE - ¾-14 NPT

NOTE It is comprised of a number representing nominal pipe size followed by the number of threads per inch and the letters NPT representing the thread series.

Discussion: ANSI/ASME B.1.20.1 is the US standard for dimensions and gageing of general purpose pipe threads. There are 6 American standard pipe thread forms and corresponding designations as outlined below. Each has the general form of nominal pipe size followed by the number of threads per inch and a designation for the pipe thread series.

3/8 - 18 NPT

1/8 - 27 NPSC

½ - 14 NPTR

1/8 - 27 NPSM

1/8 - 27 NPSL

1 - 11.5 NPSH

Each letter in the symbols has a definite significance as follows:

N= National (American) Standard

P = Pipe

T = Taper

C = Coupling

S = Straight

M = Mechanical

L= Locknut

H = Hose Coupling

R= Ralling Fittings

Pipe size and number of threads per inch may be found in ASME B.1.20.1 Table 2 , a section of which has been reproduced for reference below. TF chairmen should use these designations when identifying pipe threads.

Refer to the discussion after 6.4.8 and 7.6.1.7 and for the discussion of ASME B 1.20.1 and US tapered pipe threads.

ASME B.1.20.1 Table 2

3.39

observed

inspection or test where the purchaser is notified of the timing of the inspection or test and the inspection or test is performed as scheduled even if the purchaser or his representative is not present

3.40

oil mist reclassifier

long path orifice device which meters and controls the flow of oil mist to an application point

NOTE 1 The turbulent flow through the orifice causes the small mist particles from the header to agglomerate into larger size particles that more effectively wet the bearing surfaces.

NOTE 2 Mist reclassifies are normally screwed into the face of the manifold block and stainless steel tubing channels the mist to the application point.

3.41

oil mist directional reclassifier

oil mist classifier that points the oil mist flow directly at the bearing

NOTE Directional reclassifiers are mounted at the bearing and are used to overcome bearing windage and in those cases where mist flow through the bearing can not be otherwise assured

3.42

oil mist lubrication

lubrication systems that employ oil mist produced by atomization in a central unit and transported to the bearing housing, or housings, by compressed air

3.43

owner

final recipient of the equipment who may delegate another agent as the purchaser of the equipment

3:44

panel

enclosure used to mount, display and protect gauges, switches and other instruments.

3.45

PN

nominal pressure

numerical designation relating to pressure that is a convenient round number for reference purposes. [ISO 7268:1983]

EXAMPLE - PN 100

NOTE The permissible working pressure associated with a PN designation depends upon materials, design and working temperature and has to be selected from the pressure/temperature rating tables in corresponding standards. [ISO 7268-1983]

3.46

PMI

positive material identification testing

physical evaluation or test of a material to confirm that the material is consistent with the selected or specified alloy material designated

NOTE Adapted from API 578: 1999

3.47

potential maximum power

approximate maximum power to which a steam turbine can be uprated at the specified normal speed and steam conditions when it is furnished with larger or additional nozzles and possibly with a larger governor‑controlled valve or valves

Discussion: This is a data sheet entry on the steam turbine standards. By comparing it against the quoted HP one can determine the additional turbine capability without major modifications to the turbine such as a new shaft or inlet casing.

3.48

pressure casing

composite of all stationary pressure containing parts of the unit, including all nozzles and other attached parts

Discussion: The pressure casing may be a single wall such as a pump casing or dual wall such as a reciprocating compressor cylinder or the jacketed dry screw compressor. In the case of dual wall casings, the inside wall is designed to contain the process pressure and the outside wall to contain the pressure caused by the cooling water. Pressure casing terminology usually does not apply to diaphragms, or bearing housings.

3.49

pure oil mist lubrication

lubrication systems in which the mist both lubricates the bearing and purges the housing

NOTE There is no oil level in the bearing housing when using pure oil mist lubrication. (i.e.dry sump)

[Formatted in accordance with ISO 10241:1992 6.2.2 which states that brackets shall not be used to show alternative terms]

Discussion: Every bearing does not have a classifier directing the oil mist directly on the bearing race. Therefore, to include the wording DIRECTLY lubricates would be misleading.

3.50

purge oil mist lubrication

lubrication systems in which the mist purges the bearing housing

NOTE There is an oil level in the bearing housing when using purge oil mist lubrication and the bearing is lubricated by a conventional oil-bath, flinger or oil ring lubrication system. ( i.e.wet sump)

[Formatted in accordance with ISO 10241:1992 6.2.2 which states that brackets shall not be used to show alternative terms]

3.51

Discussion: The difference between the pure oil mist (3.44) and purge oil mist (3.45) is that the pure oil mist has a dry sump and the purge oil mist has oil in the sump. Purge oil mist purges a bearing which has a conventional oil flinger or oil ring lubrication system.

Purge oil mist systems generally are fitted with a constant level oiler type. The oiler can function as a sight glass indicator, ( to determine if too much or too little oil mist is being provided), and it can also assist in maintaining the oil level in the sump.

3.52

purchaser

agency that issues the order and specification to the vendor

NOTE The purchaser may be the owner of the plant in which the equipment is to be installed or the owner's appointed agent.

Discussion: The definition of purchaser was added to compliment the definition of owner

3.52

Ra

arithmetric average of the absolute value of the profile height deviations recorded within the evaluation length and measured from the mean line

NOTE 1 Adapted from ASME B 46.1-2002 para 1.4.1.1

NOTE 2 It is the average height of the entire surface, within the sampling length, from the mean line

Discussion: Refer to Informative Annex 2 for detailed disussion and tables explaining surface finish. These discussions and tables were too voluminous to include in the body of the Standard Paragraphs.

3.53

rolled thread

thread produced by the action of a form tool that when pressed into the surface of a blank displaces material radially. [ASME B 18.12 Glossary of Terms for Mechanical Fasteners – 2001]

3.54

roughness long-wavelength cutoff

nominal rating of the electrical or digital filter that attenuates the long wavelengths of the surface profile to yield the roughness profile

NOTE 1 Roughness long-wavelength cutoff is usually expressed in millimeters.

NOTE 2 In most electrical averaging instruments, the cutoff can be selected. It is a characteristic of the instrument rather than the surface being measured.

NOTE 3 Adapted from ASME B 46.1-2002, para. 1.3.5.

[Formatted in accordance with ISO 10241:1992 para. 5.2.5.e]

Discussion: Term is used in 6.1.20 and refer to Informative Annex 2 for detailed disussion and tables explaining surface finish. These discussions and tables were too voluminous to include in the body of the Standard Paragraphs.

3.55

radially split

split with the joint perpendicular to the shaft centerline

[Formatted in accordance with ISO 10241:1992 para. 5.2.5.a]

Discussion: Made similar to the definition of axially split

3.56

rated point

maximum specified capacity on the rated speed performance curve

Discussion: The term capacity is meant to refer to flow as well as power.

There is generally a difference between the normal operating point and the rated point since the normal operating point is where the equipment will usually operate and the rated point implies a maximum capacity point.

3.57

rated speed

100% speed

highest rotational speed (revolutions per minute) required to meet any of the specified operating conditions

Discussion: The rated speed is usually determined by either the maximum head operating point or the maximum capacity operating point. The rated speed is the speed on which the rated operating point lies. The rated speed may not be the normal operating speed since the normal operating speed is determined by the normal operating point.

For variable speed machines rated speed is not maximum continuous speed. Maximum continuous speed is 105% of the rated speed.

3.58

relief valve set pressure

pressure at which a relief valve starts to lift

Discussion: This definition is used in setting the maximum allowable working pressure (paragraph 3.17). That relief valve set pressure is the pressure at which the relief valve starts to lift and does not include accumulation. The margins built into the asme code allowable stresses account for accumulation.

3.59

remote

location of a device when located away from the equipment or console, typically in a control room

3.60

rolling element bearing effective clearance

bearings internal clearance under operating conditions

3.61

rolling element bearing initial clearance

bearings internal clearance before it is installed on a shaft or in a housing

3.62

rolling element bearing preload

compressive force acting on a rolling element bearing when the bearing has zero internal clearance

3.63

rolling element bearing seal

ring affixed to the bearings stationary race and contacting the rotating race

NOTE Seals are used primarily to retain grease in the bearing.

3.64

rolling element bearing shield

ring affixed to the bearings stationary race and having a clearance between the shield and the rotating race

NOTE Shields are used to control the flow of grease.

3.65

shall

required in order to conform to the specification

NOTE Adapted from ISO/IEC Directives Part 2: 2001

3.66

should

recommended but not required in order to conform to the specification

NOTE Adapted from ISO/IEC Directives Part 2: 2001

Discussion: Please note the important difference between “shall” and “should”. If you use the word "should" for a paragraph then you must accept that the reader may, contractually, ignore the provision entirely. If this is not what you want, then use the word "shall" (if necessary, with conditions)."

3.67

shutdown set point

preset value of a measured parameter at which automatic or manual shutdown of the system or equipment is required

3.68

soleplate

plate attached to the foundation , with a mounting surface for equipment or for a baseplate [API 619]

3.69

special purpose application

application for which the equipment is designed for uninterrupted, continuous operation in critical service, and for which there is usually no installed spare equipment

Discussion: The user determines which services are critical.

3.70

special tool

tool which is not a commercially available catalog item

3.71

standard volume flow

flow rate expressed in volume flow units at standard conditions as follows:

ISO Standard Conditions

Flow:Cubic meters per hour (m3/h)

Cubic meters per minute (m3/min)

Pressure:1.013 bar

Temperature:0 °C

U.S. Standard Conditions

Flow:Standard cubic feet per minute (scfm)

Million standard cubic feet per day (mmscfd)

Pressure:14.7 PSI

Temperature:60 °F

3.72

standby

service state in which a piece of equipment is normally idle or idling and is capable of immediate automatic or manual start-up for continuous operation

3.73

stress intensity

When the maximum shear stress theory is used to combine stresses, the stress intensity is equal to two times the maximum shear stress or the difference between the algebraically largest principal stress and the algebraically smallest principal stress at a given point

NOTE 1 Tensile stresses are considered positive and compressive stresses are considered negative.

NOTE 2 Adapted from ASME Boiler & Pressure Vessel Code Section VIII Div 2 Part AD-140(a)

Discussion: The code was revised to reduce the hydrotest pressure from 150% MAWP to 125% MAWP (in approximately 1990). The allowable stress levels of materials were increased to maintain the same hydrotest stress level at 125% MAWP hydrotest as previously occurred at 150% MAWP. This allowed pressure vessels to be designed to higher stress levels at MAWP.

3.74

System 21

thread inspection system typically utilizing fixed GO, NO-GO gages to assure interchangeable assembly of mating parts

NOTE - The threads passing this inspection fit between the maximum and minimum material limits. No dimensional data is recorded. GO and NO-GO gages only identify a product as it pertains to the maximum and minimum tolerance limits. Thread characteristics such as lead, flank angle, taper and roundness variations are confined within these limits with no specific control of their individual magnitudes. If the GO gage does not go, the thread exceeds the maximum material limit. i.e. one or more of the thread characteristics is too small for internal threads and too large for external threads. If the NO-GO gage goes, the thread is less than the minimum material limit. i.e. one or more of the thread characteristics is too large for internal threads and too small for external threads. A variable gage can also be configured to perform the GO, NO-GO inspection.

3.75

System 22

thread inspection system utilizing variable differential gages to assure interchangeable assembly of mating parts with dimensional cumulative and individual identification of critical component features or attributes

NOTE - The threads passing this inspection fit within the maximum and minimum material limits envelope. The cumulative variation of thread characteristics such as lead, flank angle, taper, and roundness is measured and confined within the maximum and minimum material envelop. Differential gaging uses two measurements. One gage is used to measure the functional diameter size, and another gage is used to measure the pitch diameter size.

3.76

System 23

thread inspection system utilizing variable differential gages to assure interchangeable assembly of mating parts with dimensional identification and smaller acceptance tolerance of critical component features or attributes than System 22

NOTE - The threads passing this inspection fit within the maximum and minimum material limits envelope. The magnitude of other thread characteristics such as lead, flank angle, taper, and roundness are further controlled within the maximum and minimum material limits. Thread characteristics (surface texture, etc.) for which no limiting requirements are specified do not require evaluation.

3.77

TIR

total indicator reading

total indicated runout

difference between the maximum and minimum readings of a dial indicator or similar device, monitoring a face or cylindrical surface during one complete revolution of the monitored surface

NOTE For a cylindrical surface, the indicated runout implies an eccentricity equal to half the reading. For a flat face the indicated runout implies an out-of‑squareness equal to the reading. If the diameter in question is not cylindrical or flat, the interpretation of the meaning of TIR is more complex and may represent ovality or surface irregularities.

3.78

trip speed

speed corresponding to the synchronous speed of the motor at maximum supply frequency at the motor terminals.[ ISO 10241 6.2.2]

Discussion: There is a definition of trip speed for an electric motor since Table 1 paragraph 6.9 uses the term Trip speed with relation to motors and paragraph 8.3.3.2.2states: The speed shall be increased to trip speed and the equipment shall be run for a minimum of 15 minutes.

3.79

trip speed

speed at which the independent emergency overspeed device operates to shut down the driver [ ISO 10241 6.2.2]

3.80

unit responsibility

obligation for coordinating the documentation, delivery and technical aspects of the equipment and all auxiliary systems included in the scope of the order

NOTE The technical aspects to be considered include, but are not limited to, such factors as the power requirements, speed, rotation, general arrangement, couplings, dynamics, lubrication, sealing system, material test reports, instrumentation, piping, conformance to specifications and testing of components. [API 671]

Discussion: If different components of the order are purchased separately by the purchaser, the responsibility for these components can subsequently be assigned to the vendor having unit responsibility.

3.81

vendor

supplier

manufacturer or manufacturer’s agent that supplies the equipment

Note to TF Chairmen: Use vendor in the documents and not supplier

Discussion: The API mechanical equipment documents address the responsibilities between two parties. For the purposes of these standards these parties are defined as the purchaser (3.40) and the vendor or supplier (3.54). There are many parties that are involved in the purchase and manufacturer of the equipment. These parties are given different titles depending on there location in the chain of the order. They may be called buyer, contractor, manufacturer, and subvendor. In all instances however, one party is purchasing something from another party. For example, the party supplying a lube oil console may be the console vendor to the compressor manufacturer, the subvendor to the purchaser, and the purchaser to components within the console. All of these terms however can be reduced to the purchaser and vendor or supplier. It is for this reason that only these two terms are defined. Attempts to define these other terms would only add confusion.

3.82

witnessed

inspection or test where the purchaser is notified of the timing of the inspection or test and a hold is placed on the inspection or test until the purchaser or the purchasers representative is in attendance

4General

4.1Unit Responsibility

The vendor who has unit responsibility shall assure that all subvendors comply with the requirements of this standard and all reference documents. [API 618]

Discussion: Typically, the vendor who has unit responsibility invokes the applicable standards to his subvendors and they in turn invoke the applicable standards to there subvendors etc. It is not intended here that the unit responsible vendor know all of the subvendors which are required to manufacture the equipment. It is sufficient for him to pass this requirement on to each of his subvendors with the stipulation that they in turn pass the requirements on to their subvendors.

4.2Unit Conversion

Discussion: The factors in Chapter 15 of the API Manual of Petroleum Measurement Standards formally API 2564 were used to convert from U.S. Customary to SI units. The resulting exact SI units were then rounded off. It should be noted that paragraph 15.4.12 EXCEPTIONS states: “ The major exceptions to SI practice are as follows:”..Sub paragraph 5

Pressure—The bar (which equals 105 pascals 100 kilopascals - kPa) is an allowable unit.

4.3Nomenclature

A guide to XXXXX nomenclature can be found in Appendix E (Note to Task Force Chairmen: Fill in the name of the equipment standard being addressed.)

Discussion: This Appendix is tutorial in nature and helps standardize on the names of various components of the equipment.

5Requirements

( 5.1DIMENSIONS

The purchaser shall specify whether data, drawings, hardware (including fasteners) and equipment supplied to this standard shall use the SI or US customary system of measurements .

NOTE - Dedicated Data Sheets for SI units and for US customary units are provided in Annex XXX.

Note to TF Chairman: Provide four boxes on each set of data sheets to allow the purchaser to specify if SI or US customary units are to be used for software (drawings, data, etc.) and fasteners.

5.2Statutory Requirements

The purchaser and the vendor shall determine the measures to be taken to comply with any governmental codes, regulations, ordinances, directives,or rules that are applicable to the equipment its packaging and any preservatives used.,. [ISO directives Part 3:1997 Annex E]

Equipment installed in the European Economic Area (EEA) shall comply with all applicable European Union Directives.

NOTE The European Economic Area includes the countries of the European Union plus Norway, Iceland and Liechtenstein.

Task Force Chairmen: Refer to Informative SP Annex 9 describing the ramifications of this statement.

5.4DOCUMENTATION REQUIREMENTS

The hierarchy of documents shall be specified.

NOTE Typical documents include company and industry specifications, meeting notes, and modifications to these documents.

6Basic Design

6.1General

6.1.1The equipment (including auxiliaries) covered by this standard shall be designed and constructed for a minimum service life of 20 years and at least 5 years ( TF Chairmen: Use 3 years for GP Equipment) of uninterrupted operation [API 617]. Shutting down the equipment to perform maintenance or inspection during the 5 year uninterrupted operation is not acceptable.[617]

NOTE 1 It is recognized that these are design criteria.

NOTE 2 It is realized that there are some services where this objective is easily attainable and others where it is difficult.

NOTE 3 Auxiliary system design and design of the process in which the equipment is installed are very important in meeting this objective. [TI 6180203]

NOTE 4 9.2.1 requires the vendor to identify any component or maintenance requirement that would result in the need to shut down the equipment within the uninterrupted operational period.

Discussion: (From TI 6180203)

Question: Since this API clause calls for "an expected uninterrupted operation of at least 3 years", my question to you is, that whether such 3 years continuous operation is really possible or not, OR, this clause neglects the downtime required for the annual maintenance or in other words,

Does API 618 insist, that the compressor be designed for 3 YEARS MAINTENANCE FREE OPERATION ?

Reply: Yes, it is the intent of this standard to provide equipment (including auxiliaries) that have been designed to provide 3 years of uninterrupted operation, without annual maintenance. It is realized that there are some services where that objective is easily attainable and others where it is more difficult. The system design is a very important criterion in meeting this objective. Note that this is a design requirement. Manufacturers may choose to recommend reduced maintenance intervals dependant upon the proposed operating conditions.

6.1.2The vendor shall assume unit responsibility for all equipment and all auxiliary systems included in the scope of the order.

Note to TF Chairmen: Suggest eliminating "unit" from standards covering such equipment as couplings, seals, and vibration monitoring, which are not usually designated as having unit responsibility.

Discussion: This paragraph requires that each vendor who is a party to an order be responsible for the equipment he is supplying. Task forces responsible for equipment not generally designated as having unit responsibility (such as couplings, seals and L. O. systems) can delete "unit" from the paragraph. This will still make them responsible for the equipment they are supplying but not necessarily the entire train.

( 6.1.3 The purchaser shall specify the equipment's normal operating point.

6.1.4. The equipment shall be capable of operating within the entire performance map at all specified operating conditions, as well as accommodating other conditions such as momentary surge, settle-out, trip and startup. [617]

6.1.5Equipment driven by induction motors shall be rated at the actual motor speed for the rated load condition.

Discussion: Due to load, the motor runs at a slower speed than synchronous. This can be several percent depending on motor slip.

( 6.1.6Control of the sound pressure level (SPL) of all equipment furnished shall be a joint effort of the purchaser and the vendor having unit responsibility and the contractor??. The equipment furnished by the vendor shall conform to the maximum allowable sound pressure level specified. In order to determine compliance, the vendor shall provide both maximum sound pressure and sound power level data per octive band for the equipment. ISO 3740 (sound power levels), ISO 3744 (sound pressure) and ISO 3746 (sound pressure) or ASME PTC 36, may be consulted for guidance. [610 uses the ISO references]

SPTF Review this Discussion: Sound pressure levels are easier to determine than sound power levels. Therefore a screening sound pressure test is performed per ASME PTC 36 (For Gas turbines use ANSI B 133.8 and ISO 10494) (Refer to OPTIONAL TESTS in Section 4) In the event that the overall sound pressure levels do not meet those specified by the p