APS Design & Drafting Standards
TABLE OF CONTENTS
PREFACE
SECTION 1 -- GENERAL DRAFTING STANDARDS
SECTION 2 -- AUTOEDMS
This section is under development
2.1 - INTRODUCTION
2.2 - LOGGING ON
2.3 - OPENING FORMS
2.4 - SEARCHING THE DATABASE
2.5 - CHECKING OUT A DRAWING
2.6 - RUNNING AUTOCAD
2.7 - CHECKING IN A DRAWING
2.8 - VIEWING AUTOCAD DRAWINGS
2.9 - CREATING A NEW DRAWING
2.10 - DCNs, DOCUMENT CONTROL NUMBERS
2.11 - LOGGING OUT
SECTION 3 -- AUTOCAD PRACTICES
SECTION 4 -- PREFERRED LIMITS AND FITS FOR CYLINDRICAL PARTS
SECTION 5 -- DRAWING NUMBERS AND REVISIONS
SECTION 6 -- GENERAL DIMENSIONING AND TOLERANCING
SECTION 7 -- SURFACE FINISH
SECTION 8 -- WELDS AND WELD SYMBOLIZATION
SECTION 9 -- SCREWS, NUTS AND WASHERS
SECTION 10 -- FACILITIES DESIGN STANDARD
SECTION 11 -- DETAILED CHECKING PROCEDURE
PREFACE
This Design and Drafting standard has been compiled in order for the Advanced Photon Source's
Design and Drafting Group to better communicate design requirements to our customers.
Through better communication, the Design and Drafting Group hopes to create a mutual
understanding of our design requirements among all of our customers.
Only if such mutual understanding exists can the Advanced Photon Source be assured that all
of our suppliers are building our needed components as we require.
When building components for the Advanced Photon Source, close adherence to the standard
established in this manual is vital. Following these standards means that the components will
meet our requirements, but more importantly, that the components supplied by the vendors will
meet the Advanced Photon Source's standard of quality for the useful life of the machine.
Although this manual presents a consolidation of available information, it is impracticable to
include all data pertinent to the fabrication of components; therefore, sound reasoning and good
judgment must be exercised in making interpretations from this manual.
Thank you
Paul Choi
The following valuable contributions were made in the development of this
manual. Sections 1 and 3-9 were coordinated by S.Sharma.
Main Contributors for the sections:
Section 1: C. Brite, S. Sharma, A. Barcikowski
Section 2: M. Eisenberg, P. Choi
Section 3: D. Prokop, E. Rotela
Section 4: S. Hanuska, G. Goeppner, S. Sharma, D. Jaskoviak
Section 5: S. Sharma, D. Shu, L. Pruitt
Section 6: E. Rotela, S. Sharma, A. Barcikowski
Section 7: D. Mangra, S. Sharma, P. Choi
Section 8: E. Trackhtenberg, I.C. Sheng, S. Sharma, A. Barcikowski
Section 9: S. Hanuska, S. Sharma, P. Choi
Section 10: D. Prokop, P. Choi
The manual was carefully reviewed by P. Belko and F. Saffrahn.
Thanks to A. Salzbrunn for typing and editing several versions of the
manual. We also would like to thank Kevin Costello and R. Fenner for the cover
drawing. ANSI Y14.5M is included as an appendix to compliment the manual.
SECTION 1 -- GENERAL DRAFTING STANDARDS
1.1 SCOPE
This section defines general rules and practices to be followed by all APS
designers and drafters to produce design drawings of consistent and professional
quality. The contents of this section are intended to be consistent with various American national standards listed in Table 1.1. Because of the broad scope of the APS design and drafting activities and the need for an accurate interpretation
of the drawings produced, any use of special or local practices is strongly
discouraged.
The accuracy and adequacy of the design and drafting work and its compliance
with the applicable standards remain the responsibility of the designer or drafter.
Nothing contained in this manual shall be construed as relieving the designer or
drafter of the individual responsibility for producing quality drawings.
1.2 GENERAL RULES
1.2.1 All drawings shall comply with rules and guidelines for dimensioning and
tolerancing given in Section 6.
1.2.2 Commercially available components are to be used whenever possible.
Catalog number, short description, supplier name, and quantities are to be
given on the parts list.
1.2.3 Each detail shall be drawn on a separate sheet except for tooling,
weldments, and architectural drawings.
1.2.4 Each detail is to contain all information needed for fabrication independent
of other drawings (with the possible exception of drill-on-assembly
techniques). This includes, but is not limited to:
(a) Specific materials called for by name, identifying number, and
specification.
(b) Material hardness and hardness depth.
(c) Annealing or stress relieving.
(d) Surface finish symbols.
(e) Weld symbols with joint sizes and other requirements (See Section
8).
(f) Testing specifications, such as pressure tests, vacuum tests, dye
penetrant tests, magna-flux tests, radiographic tests, etc.
(g) Finish specifications such as painting, plating, etc.
(h) Brazing specifications.
(i) Calculated weight for heavy components. In special cases add
provisions for lifting.
(j) Identification of all assemblies with the drawing number.
1.2.5 Sub-assemblies, in general, are to be drawn in the same orientation as
their assembly.
1.2.6 Dimensions given are to be the ones used to fabricate, inspect, and match
other parts.
1.2.7 Prints are not to leave the Laboratory with pencilled or penned markings.
Drawings are to be revised to reflect such markings. See Section S on
Drawings Numbers and Revisions.
1.2.8 All drawings are to be brought up to date and revisions noted in the revision block (see Section 7).
1.2.9 Reasonable simplified drafting practices shall be used. Repetition,
excessive use of hidden lines, unnecessary views, shading, and overuse
of section lines are to be avoided.
1.2.10 The term "TYP" shall not be used. The number of specific places must be
noted. The "X" is a full character height or upper case. (Example: 2X).
1.2.11 The use of multiple sheet drawings should be avoided if possible. If
multiple sheet drawings must be used they must all have the same log
number and document number listed in title blocks. All sheets must have the same title listed in title blocks, since DCC can enter only one (1) in the
database. All sheets must be of the same size and scale. When revising
multiple sheet drawings, the revision levels (i.e., the last two (2) digits of the log number and document number) must be updated on all sheets.
1.2.12 All dimension, text, notes will be in capital letters, block form, and aligned
horizontally with the drawing title block. The exception is for art work,
labels, and logos that are specified on a drawing.
1.2.13 All dimensions shall be decimal values. The use of fractions is to be
avoided. The exception is in the identifier for thread sizes, both fraction
and decimal values are acceptable.
1.2.14 No symbols are to be used unless otherwise approved. Only acceptable
APS abbreviations are allowed.
1.2.15 All characters height will be .13. All sectionals, views, and identifiers text
will be .25 in height and may be in BOLD characters.
1.2.16 All title block titles will reflect the W.B. S. titles description on the first four (4) or less of the title block.
1.3 VIEWS PRESENTATION
1.3.1 All drawings shall be produced using the "third angle orthographic
projection" system. The third angle system is preferred as the American
standard because the views are the same as those obtained by observing
the object from the front, top, side, or rear as indicated by directional
arrows in Figure 1.1. The arrangement of typical views is shown in Figure 1.2. A minimum number of views, necessary to completely describe the
object, shall be used.
1.3.2 Sectional views shall be placed as close as practical behind the arrows,
showing the shape and construction of the object at the cutting plane (see
Figure 1.3).
If it becomes necessary to rotate a sectional view, the degree of rotation
and direction are specified.
A sectional view must be identified by its title consisting of the full word
SECTION followed by the pair of letters; for example, SECTION A-A,
SECTION B-B, etc. Avoid use of letters I, O, Q, S, X, Y and Z for sectional views. Lettering shall be upper case.
1.3.3 Detail views shall be shown in the same plane and in the same
arrangement as in the principal view. Two ways of identifying the area of
detail are shown in Figure 1.4. The view scale is specified directly below
the view (and its title).
1.4 SECTION LINING
For general use a cross-section lining symbology depicting cast iron (see Figure 1.3) shall be used on detail and assembly drawings, regardless of actual material. When two or more materials must be identified individually in a drawing, use the material-specific symbology of the latest ANSI Standards wherever applicable.
1.5 PRINT FOLDING FORMAT
For ease of handling and filing, prints shall comply with the folding format depicted
in Figure 1.5. Final folded will be approximately 8.5 inch vertical x 11.0 inch
horizontal.
1.6 CHECK DRAWINGS
1.6.1 In general, drawings will be reviewed for general compliance with the following:
a. Established standards
b. Manufacturing feasibility
c. Dimensional tolerance considerations
d. General Safety practice
e. Simplicity
f. Economy
g. View alignment
h. Scale
i. Materials
j. Fit of mating parts
1.6.2 All reference materials should be made available to the checkers.
1.6.3 APS Design Room Check Print Procedure:
- The designer shall make a set of prints upon completion of a job. These
prints shall be stamped "CHECK PRINTS" and dated. The first set of
"CHECK PRINTS" shall be no larger than "D" size format (21.00" x
33.00").
- This set of prints shall be given to the design room manager. Designer will move files from D/D to checker using AutoEDMS.
- The design room manager will forward the prints to the checker. Rush job priorities
will be authorized by the design room manager.
- The designer will furnish reference materials and others requested by the checker.
This reference material shall include:
a. Layouts
b. Calculations
c. Reference prints of mating parts and existing parts
d. Location of coordinates
e. Copies of catalog data for purchased parts
f. Copies of the pages from the drawing numbers from which numbers have
been assigned, DCC forms, and IDP forms.
g. An up-to-date electronic file copy of the corresponding assembly.
- Signed check prints will be delivered to the design room manager. Reference data will be returned to the designer.
- The design room manager will give the check prints to the designer for updating.
- Updated originals plus check prints will be given to the checker by the designer. If
the designer makes any new changes he must notify the checker of all changes.
- The checker will back-check the drawings, sign the originals, and then return the
originals to the design room manager. The check prints and the reference material
will be filed for a reasonable length of time.
- After all signatures are on originals, they are forwarded to DCC and checker will
move the files from checker to DCC using AutoEDMS.
SECTION 2 -- AUTOEDMS
Contents in this chapter are for reference only.
AUTOEDMS 3.1 is currently under development, and new standards will follow after AUTOEDMS 3.1 is installed.
Thanks,
Paul Choi
SECTION 3 -- AutoCAD PRACTICES
3.1 SCOPE
All official APS drawings are produced on the AutoCAD system. The purpose of
this section is to outline general AutoCAD practices that have been implemented
to promote drafting efficiency, and access and portability of the design drawings.
3.2 AutoCAD PRACTICES
3.2.1 All drawings produced on the AutoCAD system shall comply with the
applicable ANSI standards and the standards not included in this manual.
3.2.2 Access to the AutoCAD system will be via AutoEDMS (see Section 2)
unless specifically exempted by the Supervisor, or the responsible
engineer.
3.2.3 A new drawing shall be initiated by downloading a standard formatted
blank drawing (via AutoEDMS) containing APS-designated title block and
border. An appropriate size FORMAT scaled to fit the drawing's
requirements shall be used. Do not explode the FORMAT.
3.2.4 Use of multiple sheets in a single electronic file should be avoided. See
Section 1.2.11.
3.2.5 Drawings shall be created with all features in full size, drawn at 1:1 scale.
3.2.6 The drawing coordinates x,y = 0,0 shall be on lower left corner of the
screen.
3.2.7 Associative dimensioning shall be used. The only exception will be when
the parts must show break lines.
3.2.8 All text shall be in ROMANS vertical font, (not slanted). Character height
will be .13 or multiples of dependent on drawing scale.
3.2.9 All dimensioning symbols will be of standard shapes and sizes. An
electronic file of the symbols will be provided by the D&D Supervisor.
Refer to latest ANSI Standards in Dimensioning and Tolerancing Book,
Appendix C, Figure C-1.
3.2.10 Hatch patterns available in the standard version of AutoCAD shall be used. (C.I. is preferred when nothing else applies).
3.2.11 Colors and line types shall be assigned by layers in all new drawings.
The layers shall be identified by names, rather than by numbers as in
the existing drawings. This will ensure the layers' uniformity in the new
drawings without causing conflict when old drawings are imported. The
layers shall be identified as follows:
LAYER | COLOR NO. |
COLOR | LINETYPE |
BORDER | 9 | Light Blue | Continuous |
CENTER | 1 | Red | Center |
DIM | 4 | Cyan | Continuous |
HATCH | 8 | Light Grey | Solid |
HIDDEN | 3 | Green | Hidden |
OUTLINE | 7 | White | Continuous |
PHANTOM | 5 | Blue | Phantom |
TEXT | 2 | Yellow | Continuous |
TB_INFO | 2 | Yellow | Continuous |
TB_TEXT | 4 | Cyan | Continuous |
TITLEINF | | Light Yellow | Continuous |
MISC | 6 | Magenta | Continuous |
3.2.12 Color number 0 (zero) shall be reserved for transporting files and
inserting blocks.
3.2.13 The line width for each layer shall remain fixed. Refer to latest ANSI
Standards for more information. (see Figure 3.3).
3.2.14 When saving the electronic file, the GRID and UCIC Icon shall be off,
unnecessary views and sections shall be eliminated, and any other
extraneous information shall be purged.
3.2.15 Dimension styles and its variables have built-in default values. These
values should not be changed or modified except for the length scale
factor, which may be modified for auxiliary views and section views,
depending on their scale.
SECTION 4 -- PREFERRED LIMITS AND FITS FOR CYLINDRICAL PARTS
4.1 SCOPE
This section covers preferred limits and fits for cylindrical parts used in the design
of APS mechanical components. The tables included in this section are based
on ANSI B4.1-1979 (R1987). For purchased parts such as shafts, dowels,
bearings, bushings, etc., fits and allowances outlined in this section shall be used
when manufacturers' recommendations are not available.
4.2 DEFINITIONS
Allowance: |
Allowance is the intentional difference between the
maximum material limits of mating parts. It is the
minimum clearance or maximum interference intended
between such parts. |
Tolerance: |
A tolerance is the total by which a specific dimension may
vary. |
Basic Size: |
The basic size is that diameter to which allowances and
tolerances are applied to achieve the limits of size for
shaft and hole. |
Fit: |
Fit is the general term used to signify the range of tightness which may result from the application of a specific
combination of allowances and tolerance in the design
of mating parts. |
Clearance Fit: |
A clearance fit is one having limits of size so prerscribed
that a clearance always results when mating parts are
assembled. |
Interference Fit: |
An interference fit is one having limits of size so
prescribed that an interference always results when
mating parts are assembled. |
Transition Fit: |
A transition fit is one having limits of size so prescribed
that either a clearance or an interference may result when
mating parts are assembled. |
Basic Hole System: |
A basic hole system is a system of fits in which the design
size of the hole is the basic size and the allowance is
applied to the shaft. This is the system used in this
standard. |
Basic Shaft System:
| A basic shaft system is a system of fits in which the
design size of the shaft is the basic size and the allowance is applied to the hole. |
4.3 SELECTION OF FITS
In selecting limits of size for any application, the type of fit is determined first,
based on the use or service required from the equipment being designed. Then
the limits of size of the mating parts are established to insure that the desired fit
will be produced. The standard fits shown herein should cover most applications.
4.4.1 RC Running or Sliding Fits: (Table 4.1)
RC 1. Close Sliding Fits
are intended for the accurate location of parts
which must assemble without perceptible play.
RC 2. Sliding Fits
are intended for accurate location but with greater
maximum clearance than class RC 1. Parts made to this fit move
and turn easily but are not intended to run freely and in the larger
sizes may seize with small temperature changes.
RC 3. Precision Running Fits
are about the closest fits which can be
expected to run freely. They are intended for precision work at
slow speeds and light journal pressures, but are not suitable
where appreciable temperature differences are likely to be
encountered.
RC 4. Close Running Fits
are intended chiefly for running fits on
accurate machinery with moderate surface speeds and journal
pressures where accurate locations and minimum play is desired.
RC 5. Medium Running Fits
are intended for higher running speeds or
heavy journal pressures or both.
RC 6. Medium Running Fits
are intended for applications where more
play than RCS is required.
RC 7. Free Running Fits
are intended for use where accuracy is not
essential or where large temperature variations are likely to be
encountered or under both these conditions.
RC 8. Loose Running Fits
are intended for use where materials such as
cold-rolled shafting and tubing, made to commercial tolerance are
involved.
4.4.2 LC Locational Clearnace Fits (Table 4.2)
LC 1 through LC 11 Transition Fits
are intended for parts which are
normally stationary but which can be freely assembled or disassembled.
They run form snug fits for parts requiring accuracy of location, through the
medium clearance fits for parts such as spigots, to the looser fastener fits
where freedom of assembly is of prime importance.
4.4.3 LT Locational Transition Fits (Table 4.3)
LT 1 through LT 7 Transition Fits
are a compromise between clearance
and interference fits, for application where accuracy of location is important
but either a small amount of clearance or interference is permissible.
4.4.4 LT Locational Interference Fits (Table 4.4)
LN 2 and LN 3 Locational Interference Fits
are used where accuracy of
location is of prime importance, and for parts requiring rigidity and
alignment with no special requirements for bore pressure. Such fits are not
intended for parts designed to transmit frictional loads from one part to
another by virtue of the tightness of fit, as these conditions are covered by
force fits.
4.4.5 FN Force and Shrink Fits (Table 4.5)
FN 1 Light Drive Fits
requires light assembly pressures and produce
more or less permanent assemblies. They are suitable for thin
sections or very long fits or in cast-iron external members.
FN 2 Medium Drive Fits
are suitable for ordinary steel parts or for
shrink fits on light sections. They are about the tightest fits that
can be used with high-grade, cast-iron external members.
FN 3 Heavy Drive Fits
are suitable for heavier steel parts or for shrink
fits in medium sections.
FN 4 Force Fits
are suitable for parts which can be highly stressed or
for shrink fits where the heavy pressing forces required are
impractical.
4.5 RECOMMENDED TOLERANCE SYSTEM
The unilateral system of tolerance is recommended, in which the tolerance on each
part (shaft and hole) is disposed in only one direction from the design size,
plus for the hole and minus for the shaft.
See Example
For an example, examine the fits and allowances of a 1" OD x 1/2" ID "home-made" sleeve bearing* carrying a rotating 1/2" OD shaft (see Fig. 4.0). It has been
determined that the bearing will be pressed into a steel plate with a medium drive
fit (FN 2), and the shaft will be given a free running fit (RC 7).
Plate/Bearing Fit from Table 4.5:
1" Nom. Size, Hole = | + 0.8 thousandths | | + .0008 |
| - 0.0 thousandths | Plate = 1.0000 dia. | - .0000 |
Shaft (Bearing OD) = | + 1.9 thousandths | | +.0000 |
| + 1.4 thousandths | Prg OD = 1.0019 dia. | -.0005 |
Bearing/Shaft Fit from Table 4.1:
1/2" Nom. Size, Hole = | + 1.6 thousandths | | + .0016 |
| - 0.0 thousandths | Prg ID + .5000 dia. | - .0000 |
Shaft = | - 2.0 thousandths | | + .000 |
| - 3.0 thousandths | Shaft OD = .4980 dia. | - .001 |
_________________________
*Purchased sleeve bearings generally come with OD oversize by the amount necessary
to achieve the proper press fit in a normal reamed hole. It is therefore necessary for the
designer to specify the hole size and tolerance to accommodate the bearing accordingto the "Limits of Clearance" in the tables, or to use the manufacturer's recommendations
if available.
SECTION 5 -- DRAWING NUMBERS AND REVISIONS
5.1 SCOPE
This section describes various drawing numbers and their use on the APS drawings. The
drawing numbers are assigned and controlled by the APS Document Control Center
(DCC). Details of the responsibilities and functions of the DCC and how they affect the
designing and drafting process are given in "Document Control Center, Hands-on Guide
for APS Users." New drawing numbers are obtained through DCN request forms.
5.2 DRAWING NUMBERS
The following drawings numbers are presently in use:
5.2.1
Log Number
A log number is a seven (7) digit number preceded by a letter (letter A at present),
that is assigned to the drawing by the DCC upon written request. This number is
assigned sequentially to the drawings as well as other APS documents. The log
numbers often appear to be at random on related drawings when the requests for
numbers are not submitted at the same time. Once a log number is assigned to
a drawing, it never changes except for its revision level designation, (i.e., its last
two (2) digits). (The last two (2) digits are for revision designation and should
coincide with the revision level of the document number).
Because of its small field length (8), the log number is easier to use in database
and DOS applications. It is, therefore, commonly used for storing, searching and
retrieving a specific drawing from a large database of drawings and documents.
In APS drawings, the log number is always used in conjunction with a drawing
number (either a Logical Drawing Number or a Prototype Drawing Number, see
below) in the title block.
5.2.2
Document Number
In September 1992 the DCC replaced the existing septum with a logical drawing
numbering system that allowed users to identify relationships between assemblies,
sub-assemblies, and their parts. A Document Number consists of three (3) parts:
(1) a WBS number, (2) a six-digit sequence, called Logical Drawing Number
(LDN), and (3) a two-digit sequence identifying the drawing revision number.
The multiple-digit WBS number, explained in "Document Control Center, Hands-on
Guide for APS Users," identifies a major component assembly of the APS Project.
The six-digit LDN is composed of three (3) two-digit sequences (see Figure 5.1),
representing (from left to right) a sub-assembly, a sub-sub-assembly, and a part.
Figure 5.1 illustrates how this hierarchical breakdown is used for a photon shutter
assembly.
The division of a major component assembly (defined by the WBS number) into
sub-assemblies, sub-sub-assemblies, and parts is the responsibility of the
cognizant engineer and his designer. For a specific drawing they propose to the
DCC a complete document number consisting of the WBS, LDN, and revision
number. The DCC's responsibility is limited to verifying that the proposed number
has not already been assigned.
In order to avoid any conflict with the old design numbers not based on LDN, the
number zero is not allowed in the first digit (left most) of the LDN. This ensures
that the assigned number will always be different from the old numbers which
contained only five (5) digits.
5.2.3
Prototype Drawing Number
A prototype drawing number has the same structure as document number except
that the former is preceded by the letter "P" indicating a prototype. This drawing
number is used when the components being designed are still in a prototype
phase and may not be used in the APS machine. When a prototype drawing is
considered to be acceptable, the prototype drawing number is converted to the
logical drawing number by dropping the letter "P" and incrementing the revision
number.
5.2.4
Sketch Number
A sketch number is a five-digit number preceded by the letter "S". Drawings with
sketch numbers are generally used by engineers and physicists to convey design
information to the design and drafting staff. Their use is restricted to R&D
activities. Although the sketch numbers are issued by the DD, it does not store
or in any way control drawings with sketch numbers.
The use of sketch numbers on the APS production drawings is not to be used. Asof January 1996 sketch numbers will no longer be used.
5.2.5
Electronic File Number
The Experimental Facilities Division (XFD) uses electronic file numbers in its
Design Exchange System, which is being set-up to exchange design drawings of
standard components between XFD, beamline users, and other outside
organizations. An electronic file number consists of a descriptive identifier of field
length two (2) followed by the logical numbering sequence (LDN) explained above
in sub-section 5.2.2. The descriptive identifier essentially replaces the long WBS
number. Its first field is a letter which represents a component group, and the
second field is a number assigned sequentially to different components of that
group.
As an example, an existing APS Drawing Number 1415972-810000-00, consisting
of WBS 1.4.1.5.9.7.2, LDN 810000, and revision 00, is identified as V2810000 in
the Design Exchange System.
5.3 DRAWING REVISIONS
5.3.1
Revision
- The term "revision" refers to any change on the drawing after the
drawing has been approved and submitted to DCC.
5.3.2
Revision Number
- The last two digits of the logical drawing number and the
prototype drawing number identify the revision number. The original release is
identified by -00, and subsequent releases are numbered sequentially from -01 to
99.
5.3.3
Document Change Note
- A Document Change Note (DCN) must be submitted to
the DCC with the revised drawings for approval and to update the database.
5.3.4
Revision Symbol
- A revision symbol is an identifying number, enclosed in an
equilateral triangle as shown in Figure 5.2. Revision symbols shall be used to
locate the revision in the field of the drawing. To avoid crowding of revision
symbols, a single revision symbol may be used to identify the changes if they are
properly identified and described in the (DCN).
5.3.5
Location
- Revision symbols shall be located as near as possible to the notes,
lines, views, or dimensions which are changed so as to minimize the number of
symbols.
5.3.6
Multiple Changes
- All changes to a drawing incorporated at one time shall be
identified by the same revision number. The changes shall be identified by a
revision tri-marker with that corresponding revision number.
5.3.7
Revising a Change
- Whenever a change is revised, a new symbol shall be placed
next to the previous one.
5.3.8
Revision Block
- Each revision shall be recorded in the revision block of the
drawing (see Figure 5.2) showing (1) revision symbol, (2) the DCN number, (3)
initials of the person making the change, (4) signed initials of the person
authorizing the change, and (5) date of the revision.
SECTION 6 -- GENERAL DIMENSIONING AND TOLERANCING
6.1 SCOPE
Rules and guidelines for dimensioning and tolerancing are intended to establish uniform
practices for specifying and interpreting design requirements. As a rule, all APS drawings
shall comply with ANSI Y14.5M-82, "Dimensioning and Tolerancing," in its entirety. If there
is a conflict, the rules given in this section shall take precedence.
ANSI Y14.5M-82 is included in this design manual as Appendix 6-A. For a quick reference,
only the most commonly used dimensioning and tolerancing requirements are outlined
below.
6.2 DEFINITIONS
6.2.1
Dimension. A dimension is a numerical value expressed in appropriate units of
measure and indicated on a drawing along with lines, symbols, and notes to define
a geometric characteristic of an object.
6.2.2
Reference Dimension (REF). A reference dimension is a dimension without
tolerance used only for information purposes and does not govern production or
inspection operations. The preferred method is to place the reference dimension
within parentheses.
6.2.3
Nominal Size (NOM). The nominal size is the designation which is used for the
purpose of general identification, that is, 1.500 IPS, .062 stock size, etc.
6.2.4
Basic Dimension. A numerical value used to describe the theoretically exact size,
profile, orientation, or location of a feature or datum target. It is the basis from
which permissible variations are established by tolerances on other dimensions,
in notes, or in feature control frames. Basic dimensions are shown on the drawing
in enclosed rectangle.
6.2.5
Maximum Material Condition (MMC). The condition in which a feature of size
contains the maximum amount of material within the stated limits of size; for
example, minimum hole diameter, maximum shaft diameter.
6.2.6
Allowance. An allowance is the intentional difference between the maximum
material limits of mating parts. It is the minimum clearance or maximum
interference intended between such parts.
6.2.7
Tolerance. The total amount by which a specific dimension is permitted to vary.
The tolerance is the difference between the maximum and minimum limits.
6.2.8
Standard Tolerances. Dimensions shown without tolerances are controlled by the
standard tolerances shown in the title block, except dimensions in welding
symbols; those labeled STOCK, NOM, REF, MAX, MIN, BASIC; and similar
dimensions that are otherwise controlled.
6.2.9
Datum. A datum is the origin from which the location or geometric characteristics
of features of a part are established.
NOT A CENTERLINE.
6.2.10
Feature. The general term applied to a physical portion of a part, such as a
surface, hole, or slot.
6.3 GENERAL DIMENSIONING RULES
6.3.1 Dimensioning of parts must convey enough information to define clearly
the engineering intent, so that no scaling of drawings is required, nor any
assumptions need to be made. Functional dimensional values is the
preferred method.
6.3.2 Each dimension must be expressed clearly so that it will be interpreted only
one way. No factional dimensions are to be used only decimal dimension
is the accepted practice.
6.3.3 No surface, line, or point may be located by more than one toleranced dimension in any one direction. If a dimension is repeated, it is marked REF.
6.3.4 Dimensions shall be selected and arranged to avoid accumulation of tolerances.
6.3.5 Dimensions are shown on the view that most clearly represents the form
of the feature being dimensioned.
6.3.6 Dimensions are shown outside the outline of the part unless clarity is
impaired.
6.3.7 Dimensioning to hidden lines shall be avoided.
6.3.8 Dimensions must be selected to give the required information directly so
that no calculations are needed to arrive at usable figures.
6.3.9 Where practicable, the finished part should be defined without specifying
the manufacturing method. Thus, only the diameter of a hole is given
without specifying how it is to be produced.
6.3.10 Dimensions out of scale shall be avoided.
6.3.11 Unidirectional dimensioning is to be used, that is, all dimensions and notes
should be aligned with the bottom of the drawing.
6.4 UNITS OF MEASUREMENT
6.4.1 All drawings produced by APS (except the Conventional Facilities Division)
shall use the inch as the unit of measurement as per ANSI Y14.5.
6.4.2 On drawings that are not to be released for production or fabricatioin (e.g.,
drawings for machine physics layout, beamline layout, survey and
alignment networks), units of meters or millimeters may be used as primary
units with or without equivalent inch dimensions in brackets. The drawing
should indicate in a note that this drawing is a metric drawing.
6.5 APPLICATIONS OF DIMENSIONS
Dimensions are applied with dimension lines or as notes with leaders. Dimension
lines indicate linear distance between feature centers or surfaces directly or by the
use of extension lines (see Figure 6.1).
6.6 TOLERANCING
Dimensional tolerances may be expressed as follows:
6.6.1
Title Block Tolerancing
- The tolerances are specified in the title block and
depend on the number of decimal places used in the basic dimension
(Figure 6.2).
6.6.2
Limit Tolerancing
- The high (maximum) value of a dimension is placed
above the low (minimum) value as shown in Figure 6.3.
6.6.3
Plus and Minus Tolerancing
- The basic dimension is followed by plus and
minus tolerance values (Figure 6.4).
6.6.4
Geometric Tolerancing
- The tolerances are defined by means of a Feature
Control Frame (Figure 6.5) which specifies dimensional limits for an
individual geometric feature such as location, orientation, form, profile and
runout. The Feature Control Frame is divided into several compartments
containing (1) geometric characteristic symbol (which is, when applicable,
preceded by a diameter symbol), and (3) datum references as needed.
Symbols used for geometric tolerances are shown in Figure 6.6. These
symbols can be down-loaded from a CAD file available from the design
room supervisor.
Figure 6.7 shows typical uses of geometric tolerances on a drawing.
6.7 GENERAL TOLERANCING RULES
6.7.1 Tolerances shall be assigned, directly or as default values, to all
dimensions in a drawing.
6.7.2 Title block default tolerances shall be used whenever feasible or modified
for the drawing requirements.
6.7.3 For stock such as bars, sheets, tubings, and structural shapes, tolerances
established by industry or Government standards shall apply unless
geometric tolerances are specified explicitly.
6.7.4 Tolerances shall be specified to meet actual design requirements. Do not
use restrictive tolerances simply because they can be easily generated on
a CAD station.
6.7.5 Bilateral tolerances should be selected instead of unilateral tolerances
when plus and minus tolerancing is used. Preference should be given to
equal plus and minus values.
6.7.6 Tolerances shall have the same number of decimal places as the base
dimensions, and have the same character height as the dimensions.
SECTION 7 -- SURFACE FINISH
7.1 INTRODUCTION AND SCOPE
This section outlines the method for specifying the geometric characteristics of
surface irregularities in APS. Surface roughness, waviness and lay are the only
surface irregularities to be considered unless otherwise stated in APS drawings.
These symbols and numerical value classifications shall be used to define the
roughness, waviness and lay of a surface in APS drawings.
7.2 APPLICABLE DOCUMENTS
MIL-STD-100 | Engineering Practice |
ANSI B46.1 | Surface Texture, Surface Roughness, Waviness and Lay |
ANSI Y14.36 | Surface Texture Symbols |
ISO 468 | Surface Roughness-Parameters, Their Values and General
Guidelines |
ANSI B46.1 and ANSI Y14.36 must be stated on all APS drawings when surface
irregularities need to be controlled.
7.3 DEFINITIONS AND TECHNICAL ISSUES
All terms related to the surfaces of solid material shall be defined per ANSI B46.1
and ANSI Y14.36. These terms are summarized in Figures 7.1, 7.2, 7.3, and 7.4.
Some commonly used terms are outlined as follows:
Surface
- The surface of an object is te boundary which seperates that object from
another object. Substance or space and produced by such means as abrading,
casting, coating, cutting, etching, plastic deformation, sintering, wear, erosion, etc.
Roughness
- Roughness is the surface feature of random and repetitively spaced
minute or smaller from the center line. Roughness height is the measured profile
height deviation taken within sampling length. The average spacing between
adjacent peaks is known as the roughness width spacing.
Waviness
- Waviness is a more global surface feature than roughness. It is the
mean surface upon which roughness can be superimposed. Waviness height is the
peak-to-valley height of the modified profile from which roughness and flaws have
been removed. The average spacing between adjacent peaks of such a surface
is known as the waviness width spacing.
Thus, waviness refers to the larger mean surface upon which roughness is
superimposed. However, the roughness number defined deviation from mean
centerline.
Lay
- Lay defines the direction of the predominant surface pattern. This surface
pattern or tool mark is determined by the production method used. This feature
may be necessary in sealing of joints and sliding applications of mating surfaces.
It is important to note that these numerical values have dimensions. In APS, the
dimensions shall be micro-inches for roughness height and inches for waviness
height, waviness width and roughness width unless otherwise stated. Most
standard and common machining operations are good for roughness height about
63 micro-inches. A summary of the roughness height of other machining practices
are included in one of the attached.
So do not specify surface finish control in metric format whenever it can be done. Finally, better surface finish is very costly. So care must be taken not to request
better surface finish than required.
In communicating with metric dimensions, these dimensions and their meaning are
going to be quite different.
SECTION 8 -- WELDS AND WELD SYMBOLIZATION
8.1 SCOPE
Preferred design and drafting practices for welds and welding symbolization are
given in this section. As a policy, weldments shown on the APS drawings shall
conform to the established procedures recommended by the American Welding
Society, and the weld symbols shall comply with the ANSI/AWS A2.4, "Symbols
for Welding and Non-destructive Testing".
Weld designs for ultra-high vacuum (UHV) components shall follow additional
guidelines provided in this section.
8.2 DEFINITIONS
8.2.1
Welding
- Welding is a process in which metals are joined by inducing
melting at the abutting surfaces. Welding may be performed with our
without the use of a filler metal.
8.2.2
Welding Processes
- Welding processes may be classified into the following
main categories:
Induction Welding (IW): | |
Arc Welding (AW): | Submerged arc, inert gas metal arc,
atomic hydrogen, shielded metal arc, carbon arc, twin carbon arc. |
Gas Welding (GW): | Air acetylene, oxy-acetylene, oxy-hydrogen, gas pressure, (not
recommended for vacuum applications). |
Thermit Welding (TW): | Pressure and non-pressure, (not
recommended for vacuum applications). |
Resistance Welding (RW): | Spot, seam, projection, flash, upset,
percussion. |
Electron Beam Welding (EBW): | |
Laser Welding (LW): | |
Pulse-arc Welding (PAW): | |
Diffusion Welding (DFW): | |
8.2.3
Weld Symbols
- Weld symbols are ideographs used to represent the type
of weld specified. Figure 8.1 shows the most commonly used weld symbols
and examples of their use. Refer to ANSI/ASW A2.4 for a complete list of
weld symbols.
8.2.4
Supplementary Weld Symbols
- Supplementary weld symbols, shown in
Figure 8.2, are used to provide additional information about the extent of
the weld, where and how welding is performed, and the contour of the weld
bead.
8.2.5
Welding Symbols
- Welding symbols are graphical symbols made up of up
to eight elements that convey explicit welding instructions. The eight
elements, shown in Figure 8.3 are: reference line, arrow, basic weld
symbols, dimensions and other data, supplementary weld symbols, finish
symbols, tail and specification, and process or other reference.
8.3 WELD DESIGN FOR UHV COMPONENTS
8.3.1 Water-to-vacuum welds (as well as brazed joints) are not allowed.
8.3.2 Vacuum welds between dissimilar metals must be avoided (electron beam
welds between copper and stainless steel may be allowed in special cases).
Brazing between copper and stainless steel, and explosion bonding
between aluminum and stainless steel are acceptable.
8.3.3 Preferred UHV weld designs are depicted in Figure 8.3. Unacceptable weld
designs are shown in Figure 8.4.
8.3.4 Fabrication drawings shall provide proper allowances for weld shrinkage
when an accurate positioning of the UHV components is required.
8.3.5 Weld bead protrusions into the UHV chambers shall comply with the
accelerator physics requirements (aperture, x-ray heating, etc.).
8.3.6 Changes in material properties (yield strength, ductility, permeability, etc.)
in the heat affected zone must be taken into account in designing weld
joints.
8.3.7 A note shall be added to the drawing prohibiting use of filler metals (and
brazing alloys) containing low vapor pressure materials (for example, lead,
zinc, cadmium phosphorous).
SECTION 9 -- SCREWS, NUTS AND WASHERS
9.1 SCOPE
This section specifies a preferred list of screw type fasteners and washers to be
used on APS components. It covers only a limited set of screws, nuts, plain and
lock washers that meet most of our general requirements. It in no way shall
restrict the use of other materials or types where design problems deem them
necessary.
9.2 DIMENSIONS
The dimensions of the various fastener elements are given in the respective
American national Standards Institute standards cited in Table 9.1. Plain washer
dimensions are tabulated in Table 9.2. The "TAD DATA" Screw Data Slide
Calculator shall serve as the dimensional reference for the standard screws and
lock washers. This slide gives data on screw sizes #0 - 1 in. diameter which
probably represents 95% of our requirements. For other sizes, refer to the
respective standards.
9.3 MATERIALS
The materials covered by this standard are limited to steel, stainless steel and
brass. These are identified by the respective ASTM standards or as noted in
Table 9.1. Material call out shall follow examples shown in Table 9.1.
9.4 SCREW SIZES
Although this standard does not restrict choice of sizes, Tables 9.3 and 9.4 list the
sizes that are commercially available. However, preference should be given to
sizes listed in the Argonne Stores Catalog. It is recommended that the UNC series
be specified for machine screws because coarse threads make up the bulk of
production. The notable exception is size #10-32 where a full selection of lengths
is available. Recommended tap drill sizes are given in Table 9.5.
9.5 THREADS
Threads are to be manufactured in accordance with the coarse, fine or 8-thread
series, class 2A or class 3A, of ANS B1.1, "Unified Screw Threads". Socket
screws shall, however, be manufactured to the UNR Thread Series (ANS B1.7)
with controlled root radius.
9.6 DRAWING REPRESENTATIONS
Screws, bolts, nuts and threads shall be represented in drawings as shown in
Tables 9.1, 9.2, 9.3, 9.4, and 9.5.
9.7 SUSPECT/COUNTERFEIT PARTS
The U.S. Department of Energy and the Argonne National Laboratory are
concerned that Suspect/Counterfeit parts and materials are not incorporated into
APS systems and components. A list of Suspect/Counterfeit parts will be provided
to the successful bidder of goods and services. The awarded seller of items and
services to the APS will assure that none of the indicated Suspect/Counterfeit parts
and materials are incorporated or installed on or within components or equipment.
These special requirements will be noted within drawings, specifications,
statements of work, and general instructions.
Typical Notification Statement on APS Drawings
NOTE:
This drawing/application requires the use of high-strength fasteners such as grade
5 or grade 8 bolts. In an effort to prevent the introduction of Suspect/Counterfeit
parts into APS components, a list denoting unfavorable fastener manufactures will
be provided by ANL/APS Procurement. The Suspect/Counterfeit fasteners, (as
noted by their headmarkings), are not to be used in the construction or installation
of items identified within this drawing.
SECTION 10 -- FACILITIES DESIGN STANDARD
10.1 SCOPE
The following standards defines in general the measures to be taken by A/E-Firms and Design Build Firms doing work for APS Project. This will assure
compatibility between the above mentioned firms and the APS Engineers,
Designers and Drafters, and will provide drawings and designs of professional
quality at minimum cost to the Project.
Consistent with the objective of this standard is the need to discuss with and
achieve with the above mentioned firms agreement as to the particular drafting
methods employed.
Because of the broad scope of APS design and drafting activities and the need
for universally uniform interpretation of such work, avoid local and special drafting
practices. ANL standards and practices are intended to be compatible with those
of industry and governmental agencies, therefore the following general drafting
standards are presented.
Special deviations proposed by the A/E-Firms or Design Build Firm shall be
discussed with the Project of CADD manager prior to implementation. If it is
concluded that such deviations will benefit the work and will not jeopardize the
compatibility of electronic files or the reliability of the resulting construction, the
specific deviations will be permitted. No such deviations will serve as a blanket
revision of these standards.
10.2 FLOOR PLAN ORIENTATION
Floor plans are to be oriented with north arrow pointing either up or to the right -
never down or to the left.
10.3 DRAWING SCALES
10.3.1 Plans
All floor plans for construction drawings will be drawn at a scale of
1/4" per ft. If this is not feasible, downsizing is permitted to 1/8" of
1/16" upon approval of the Project Manager.
Increasing size of the floor plans is permissible by a factor of 1/8" per
ft. (Example, 3/8", 1/2").
Group details and sections as much as possible to maintain uniform
scale on individual sheets. Do no combine details of one scale with
a floor plann of a different scale on the same sheet.
10.3.2 Elevations
Building elevations, interior elevations and building cross sections
shall be drawn at a minimum of 1/4" per ft. (Preferred).
Increasing or decreasing size of building elevations, interior
elevations, and building cross sections is acceptable at a rate scale
of 1/8" per ft. (Example, 3/8", 1/2", 1/4", 1/8").
10.3.3 Details and Sections
Details and sections shall be drawn in scale utilizing either 1/2" = 1'-0", 1" = 1'-0", 1 1/2" = 1'-0", 3" =1'-0". If details or sections are not
drawn in scale, deviation will be noted., i.e., scale: N.T.S.
10.4 DRAWING SCALE PROVISIONS/NOMENCLATURE
All electronic drawing files will be drawn to limits, i.e., scale; no electronic files will
be accepted when drawings are plotted at a different scale than what is shown
on the drawing. All drawings will have conventional architectural and engineering
scales: Example:
Architectural | All Engineering Disciplines |
1/16" = 1'-0" | 1" = 10' |
3/16" = 1'-0" | 1" = 20' |
3/8" = 1'-0" | 1" = 30' |
1/8" = 1'-0" | 1" = 40' |
1/4" = 1'-0" | 1" = 50' |
3/8" = 1'-0" | 1" = 60' |
1/2" = 1'-0" | 1" = 100' |
3/4" = 1'-0" | 1" = 200' |
1" = 1'-0" | 1" = 300' |
1-1/2" = 1'-0" | 1" = 400' |
3" = 1'-0" | 1" = 500' |
6" = 1'-0" | 1" = 600' |
All deviations must be approved prior to usage by APS Project Manager or APS
CADD Manager.
10.5 DRAWING REDUCTION
If drawings are reduced from their original size for publication, etc., the following
note must appear on the drawing: "
Warning - This Drawing Has Been Reduced."
10.6 DIMENSIONING
All dimensions shown on drawings will be true dimensions to the graphic
representation shown, if not, dimensions will be accompanied by the following:
Example:
4'-0" |
______________________ |
N.T.S. |
|
or |
4'-0" |
______________________ |
10.7
PLOTTING
A plotting schedule will be provided on each drawing defining screen colors and
pen weights used to create the drawing. See Figure 10.1 for further information.
10.8 MANUAL DRAWN DETAILS, SECTIONS, ELEVATIONS, FLOOR PLANS, ETC.
Manual drawn details, sections, elevations, etc. shall be avoided. If this system
is utilized for whatever reason, the A/E and D/B firms, at there own expense, will
provide an electronic scan file of these drawings, suitable for use in AutoCad.
Mixtures of CADD files with manual methods of drafting, i.e., line work plus cut
and paste will not be acceptable unless they are scanned at the A/E and D/B
expense and provided in an electronic file suitable for use in an AutoCad format.
All drawings shall include both a standard scale and a graphic scale.
10.9 DRAWING SHEETS
10.9.1 Material
Final original drawings shall be presented on Vellum or Polyester
Film - 3 MIL Matte Polyester Film (Mylar) finish on both sides if hand
generated. Vellum if drawings are electronically generated and a
copy is plotted on a plotter.
10.9.2 Size
Standard sheet sizes shall be as shown below. Select size to
maximize drawing efficiency. All drawing sets/packages shall be of
one size only.
Standard Sheet Sizes (Inches)
Letter | | |
Designation | Width | Length |
A | 8-1/2 | 11 |
B | 11 | 17 |
C | 17 | 22 |
D | 22 | 34 (Preferred) |
E | 34 | 44 |
F | 28 | 40 |
10.10 TEXT
Standard text fonts will be used. These are as provided in AutoCad and ASG.
Deviations in font styles will be submitted for approval prior to usage. See Figure 10.2 for further information.
All notes, headings, legend, etc., will be placed on default layers as prescribed
in AutoCad/ASG. Deviations will be accepted if placed on a layer called "text"
any further deviations will be submitted for approval prior to usage.
Insofar as all drawings are drawn to scale, i.e., limits, text must also be drawn to
the appropriate scale. See Example #5 for further information.
10.11 CADD COMPATIBILITY
All A/E's shall provide ANL with electronic drawing data compatible with
APS/CFG in-house CAD System. The following is a list of CADD computer
programs being used by the APS Project at this time:
AutoCad - Version 11.0 or 12.0
ASG - CORE - Version 6.0A
ASG - Architectural - Version 6.0
ASG - Structural
ASG - Electrical
ASG - Mechanical
1. H.V.A.C.
2. Piping
3. Plumbing
ASG - Data Link
ASG - Model Vision
ASG - Topo/Cogo (Civil)
10.12 SYMBOLS
Symbols shall be as per the standard systems in the latest versions of AutoCad,
ASG. Should non-standard symbols be required, prior written approval shall be
obtained from the APS CADD System Manager.
See Section 10.11 CADD COMPATIBILITY for a specific program.
10.13 LAYERING
Layering shall be as per the standard layering system in the latest versions of
AutoCad, ASG. Should non-standard layers be required, prior written approval
shall be obtained by the APS Project Manager or CADD System Manager. (See
Figure 10.3). See
Section 10.11 CADD COMPATIBILITY for specific program.
10.14 ABBREVIATIONS
Abbreviations shall be used only when their meanings are unquestionably clear
and shall be per ANSY Y1.1, "Abbreviations for Use on Drawings and in Text,"
of the American Society of Mechanical Engineers.
When abbreviations are used, the words and/or terms and their abbreviations
shall be defined in a legend.
10.15 REVISIONS AND MODIFICATIONS
Revisions and modifications to CADD files must be done electronically, no hand
changes will be accepted, this includes reversional changes in the title block.
10.16 FACILITY DOCUMENT NUMBER
10.16.1 General description of identification system.
A technical document shall be identified by the assignment of an
alphanumeric designation consisting of a Project Identifier, Document
Status Identifier, and Document Identifier (sheet number) as follows:
XXXXX-XXX | X | XXXX |
Project Identifier | Status Identifier | Document Identifier |
The project identifier is assigned by the Document Control Center
upon request of the ANL Project Manager.
The document status identifier shall denote the project phase in
which the document was originated and shall have one of the
following alpha codes:
-
"P" - Pre-Conceptual or Feasibility
-
"S" - Conceptual Design
-
"D" - Preliminary Design - Title I
-
"W" - Final Design - Title II
-
"T" - Tenant Layout
-
"G" - General
The document identifier shall identify the type of document and the
corresponding assigned number. This shall be an alpha code to
denote the document type, i.e., drawing or non-drawing.
A drawing-type document shall be denoted by the particular
discipline associated with the drawing as follows:
-
"A" - Architectural
-
"C" - Civil
-
"E" - Electrical
-
"F" - Fire Protection
-
"G" - General
-
"I" - Interiors
-
"L" - Landscaping
-
"M" - Mechanical
-
"S" - Structural
-
"T" - Non-Drawing Document
Each drawing document shall be numbered sequentially within its
associated discipline.
For the purpose of clarity, wherever practical the same numerical
number(s) should be assigned to the floor plans in all disciplines.
For example, if 2 is assigned to a floor plan in architectural discipline,
then 2 should be assigned to the same floor plan in mechanical and
electrical disciplines.
10.16.2 Example:
- Drawing Documents
J0046-101-D-A001
J0046-101-D-E001
- Non-Drawing Documents
J0046-101-D-T001
J0046-101-W-T001
(See Figure 10.4)
10.17 CADD FILE NAME
A CADD file shall be identified by a 12-character name. It shall consist of an 8-character file name, a period, and a 3-character file extension.
10.17.1 Elements of a Cadd File Name
a. Characters 1 thru 3 shall reflect the building number or utility.
Example:
XXX XXXXX . XXX
Building No. | Sequential No. | Dwg. (Default) |
Facility No. | 00001 |
| 00002 |
400 - Experiment Hall
410 - Control Center
500 - Site Utilities
(See Figure 10.4)
10.17.2 Additional Information
a. The following information shall also be provided along with the
electronic files.*
- Listing of all WBLOCKS and BLOCKS incorporated.
- Customized LISP routines.
- Drawings List.
- Linetypes, symbols, etc.
- Listing of all text fonts and styles used other than the
stock font files offered in AutoCad or ASG.
b. The 5-digit code shall be a unique number sequentially
assigned throughout the project and each sheet will be
uniquely numbered.
c. File Extension.
The 3-character file extension shall always be DWG for
AutoCAD files.
d.
Examples:
40000001.DWG
40000002.DWG
40000010.DWG
40100001.DWG
40100102.DWG
10.18 SECTION AND DETAILING NOMENCLATURE
The letters for sections will be in sequential order beginning with the letter A
through Z. If more letters are required, a double-lettering system will be
employed, such as AA, BB, etc.
The numbers for details will be in sequential order beginning with the number one
and so on. (See Figure 10.5).
10.19 TITLE BLOCK
A title block for each project shall be provided to the A/E and D/B firms for their
use in either an AutoCad DWG or DXF format. A sample is enclosed. (See
Figure 10.1).
10.20 ELECTRONIC DRAWING REVIEW
Electronic drawing files will be submitted for review at various stages of the
project; typically interim files shall be submitted at approximately 2 week periods
for review by the CADD Manager to insure adherence to the general drafting
standards as specified.
The electronic files will be reviewed for the standards listed and the following
generally accepted CADD practices.
- Unnecessary fragmented lines.
- Improper layering as described.
- Improper text size and fonts.
- Scale.
- Dimensioning Scale.
- Unnecessary electronic files.
a. Pieces or blocks outside the electronic border.
- Multiple blocks, lines, text inserted on top of each other, etc.
10.21 FINAL SUBMITTAL OF DRAWINGS
Drawings shall be presented on Vellum or Polyester Mylar film as stated in
Section 10.9.1, and on 5-1/4" or 3 1/2" high density, 1.2 megabyte diskettes or
5 1/4" 90/120 megabyte bernoulli cartridges for larger projects. As technology
progresses, other electronic media may be used contingent on approval of the
Project Manager or CADD Manager.
SECTION 11 -- DETAILED CHECKING PROCEDURE
11.1 SCOPE
This section defines general rules and practices to be followed by all APS
checkers to check drawings for consistency and professional quality.
11.2. Checking practice will be as follows:
a. Acceptable data will be acknowledged by the use of the color
YELLOW.
b. Corrected or revised data will be denoted by the use of the color
RED.
c. Back-checking will be acknowledged by the application of the color
YELLOW (or other contrasting color) over the previously noted RED.
Legibility of notations must be preserved.
d. Final checked drawings must be signed by all persons designated in the
title block.
e. Detailing Checklist:
- Inspect the drawing to see that the projections and sections are
made in such a way as to show most clearly the form of the piece
and the work to be done on it. Make sure that any workman looking
at the drawing will understand what the shape of the piece is and
how it is to be molded or machined. Make sure that the delineation
is correct in every particular, and that the information conveyed by
the drawing as to the form of the piece is complete.
- Check all dimensions to see that they are correct.
- Scale all dimensions and see that the drawing is to scale and that
dimensions are associated dimensions.
- See that the dimensions on the drawing agree with the dimensions
on the layout.
- Wherever any dimensions is out of scale, see that the dimension is
so marked. ( XX ). X.XXX this practice is not recommended.
- Investigate any case where the dimension, the scale of the drawing,
and the scale of the layout do not agree.
- See that all figures are correctly formed and that they will print
clearly, so that the Shop can easily read them correctly.
- See that the overall dimensions are given.
- See that all dimension extension lines go to the correct part of the
drawing.
- See that all arrow points go to the correct dimension extension lines.
- See that proper allowance is made for all fits.
- See that the tolerances are correctly given where necessary. Ask if
you don't know the tolerances to be applied.
- See that all dimensions given agree with the corresponding
dimensions of adjacent parts.
- Be sure that the dimensions given on a drawing are those that the
machinist will use and that the worker will not be obliged to calculate
in order to obtain the necessary measurements for machining or
checking his work.
- Avoid strings of dimensions where errors and tolerance can
accumulate. It is generally better to give a number of dimensions
from the same reference surface or center line.
- When holes are to be located by boring on a horizontal spindle
boring machine or other similar machines give dimensions to the
centers of bored holes in rectangular coordinates and from the center
lines of the first hole to be bored, so that the operator will not be
obliged to add measurements or transfer gages.
- Give all weld sizes, show proper weld symbols, and insure
accessibility for all welds.
- Show weldment cuttings only when necessary.
- Provide "breather" holes on closed weldments.
- Study the sequences of operations in machining, and see that all
finish marks are indicated. Try to make the part in your mind with
the information shown on the drawing.
- See that the finish marks are placed on the lines to which
dimensions are given.
- See that methods of machining are indicated where necessary.
- Insure adequate stock for machining.
- Give all drill, ream, and tap sizes.
- Insure proper use of geometric tolerancing symbols.
- Avoid special taps, drills, reamers, etc. unless such tools are
specially authorized.
- Where parts are right- and left-handed, be sure that the hand is
correctly designated. No drawing should contain both parts.
- When possible, make parts symmetrical, as to avoid making them
right- and left-handed, but do not sacrifice correct design or
satisfactory operation to accomplish this.
- When heat treatment is required, the heat treatment should be
specified. Ask, if uncertain, of the proper heat treat process.
- Verify the title, the scale, the drawing number, and series on both the
drawing and the drawing record sheet.
- Note required finishing operations, i.e., amoloy, electroless nickel,
black oxide, etc.
- Utilize 1/16, 1/8, 1/4, 1/2, and full-scale only, for details. Consult with
the standard design supervisor for exceptions.
- Consider the kind of material required for the part and the various
possibilities of casting, forging, welding, or otherwise forming the part
from this material. Then consider the machining operations to see
whether changes in form or design will reduce the number of
operations or the cost of machining.
- See that parts are detailed with reference to the economical use of
material, and whenever possible, utilize standard sizes of stock and
material readily obtainable. In the case of alloy steel, special bronze,
and similar materials, be sure that the material can be obtained in
the size required.
- Insure that the Bill of Material on assembly drawings properly calls
out the type of material, stock size, quantity required, vendor part
number, and source.
- When preparing assembly drawings, see that the part can readily be
assembled with the adjacent parts.
- Make sure that in being assembled, the piece will not interfere with
other pieces already in place and that the assembly can be taken
apart without difficulty.
- When specifying purchased components, insure complete information
for ordering, including correct catalog numbers.
- When using purchased components, insure proper interfacing with
fabricated parts, i.e., tapped holes, bearing fits, shaft diameters,
mounting feet, etc.
- Utilize standard APS hardware whenever possible.
- When detailing a new casting, assign a new pattern number.
- Insure proper application of standard APS drawing note stamps.
- Obtain from the design engineer, and note on the assembly drawing,
any applicable information regarding motor speeds, traverse rates,
pulley ratios, specification number, technical information, etc.
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