1.14T

Power Plant
Piping
Symbols &
Conventions

DRAFTING SYMBOLS AND NOTATIONS (Continued)

T. Piping symbols, conventions, and fabrication details for use in the
preparation of piping drawings are illustrated as listed below:

SCOPE .15 It is necessary that certain drawings be prepared in accordance with special standards and instructions. The following paragraphs contain specific instructions for the preparation of basic structural design drawings; heavily reinforcedconcrete structure design drawings; basic structural-steel design drawings; lighting installation plans; wiring diagrams for switchboards; preliminary estimate drawings; specifications and construction drawings; and illustrative drawings, maps, and charts. Conventional notations for various classes of drawings are described in Paragraph 1.14.

BASIC .16 STRUCTURAL

DESIGN DRAWINGS

HEAVILY REINFORCEDCONCRETE .17

STRUCTURE

DRAWINGS

Stability
Analysis

Loading Diagram

The first step in the design of every major structure should be the preparation of such basic structural design drawings as are necessary to record and summarize the general design data and assumptions and to indicate the principal features of the proposed design. No work on the preparation of detailed designs and drawings should be undertaken until the basic structural designs have been approved. The basic structural design drawings should be prepared and arranged in such complete form as to answer all questions regarding the basic structural design and the adequacy of the construction proposed; they should serve as master drawings for use, after approval, as the basis of the detailed outline and reinforcement drawings. For less complicated reinforcedconcrete structures, a somewhat different arrangement of basic data may be used, but in all cases the main loadings and other basic data and assumptions should be recorded on one or more basic design drawings as required.

For heavily reinforced concrete structures, including power plant and pumpplant buildings, the basic design and the controlling data and assumptions will generally be summarized on three drawings, as described below:

A. The stability analysis drawing should demonstrate the ability of the structure
as a whole to withstand any principal overturning or other destructive
forces. It should clearly show the individual exterior loadings for the
various cases, the assumed areas of the base and structural sections, the
distribution of normal and shearing forces at critical sections, the location
of the principal contraction joints, the uplift assumptions, and any other
principal features entering into the calculation of the stability analysis as
a whole.

B. The loading diagram, so far as practicable, should show the location and
distribution of all forces, both exterior and interior, that enter into the
calculation of the principal structural sections and reinforcement. In
addition to the uplift and foundation pressures, the loading diagram should
show the principal live loading, including floor loadings, generator and
other equipment loads, scrollcase pressures, assumed uplift for draft-
tube mat design, distribution of vacuum loading over the draft tube, and
other internal and external forces affecting the calculation of stresses. All
estimated dead and equipment loads indicated on such drawings should be
rechecked as soon as final detailed construction drawings and manufacturer's
equipment loadings are available. All originally estimated loadings should
be marked with the suffix E (estimated); the actual loadings as revised on

1.17C

SPECIAL STANDARDS AND INSTRUCTIONS (Continued)

the basis of actual weights should be marked with the suffix F (final),
including appropriate explanatory notes.

C. The reinforcement design diagram, so far as practicable, should show or indicate the location of the principal contraction and construction joints and the size, location, arrangement, and distribution of the principal reinforcement, including temperature and shrinkage steel.

Basic designs for structural-steel work, including substations, should in all
cases show or indicate the design loadings, including the wind loads. For
small structures the loadings may be indicated on the first sheet of the regu-
lar steel drawings. For major structures, a basic structural design data draw-
ing or diagram, combining so far as practicable all loading data and shear and
moment diagrams, will ordinarily be required, particularly for rigid frames
such as may be used in powerhouse structural-steel designs, gantry crane
runways, and other similar features.

.19 Drawings for lighting installations should cover the complete installation. The corresponding bills of materials should be divided into two parts, one for material required prior to the erection of the unit and the other for the material required to complete the installation.

A. In plan views, lighting conduits are shown superimposed upon the plan of the area to be illuminated. Conduits embedded in the floor are shown on the plan of the next lower elevation. The divisions between plan drawings are the finished floor levels, which are indicated by the elevations in the title.

B. The mounting dimension indicated near the lighting fixture on plan drawings
is the over-all distance from the face of the outlet box to the lowest point
of the fixture for pendant units. For bracket-type units, this dimension
indicates the vertical distance from the center line of the outlet box to the
lowest point of the fixture. No dimensions are required for ceiling-type
or flush-type units.

C. All lighting units should be connected to branch circuits with extra-flexible asbestos-covered fixture wire, using No. 12 for all units 750 watts or more and No. 14 for units less than 750 watts.

.20 Back-of-board wiring diagrams of bench-type boards should be made with the
bench section swung into a vertical plane with the top and bottom sections.
Each section should be outlined by a dash and dot line and drawn one directly
above the other. Outlines of instruments and switchboard equipment should
be shown in lighter lines than wiring. (See also Subparagraph 1.14Q.) Panel
wiring diagrams of switchboards should be drawn with all devices and their
terminals in approximate relative location and with internal connections shown
if space permits. If the internal connections cannot be drawn complete on the
panel wiring diagram, an internal wiring diagram of the device should be shown
elsewhere and, if on another drawing, reference should be made to the drawing.
For control and instrument switches, tables should be drawn indicating contacts
closed in each position of the switch. A table for a typical control switch is
shown in Figure 58, Sheet 2. Each device should be labeled with the standard
device designation shown in Figure 53, if applicable. The device designations
should be made heavier than other lettering on the diagram.

.21 Preliminary estimate drawings of dams should include, on a detailed
topographic map of the site and the area immediately adjacent thereto: a
large-scale general plan of all proposed permanent construction; a profile on
the axis of the dam; a developed upstream elevation, and for earth dams a
developed downstream elevation; a maximum cross section of the dam; a
center-line profile section through the spillway; a center-line profile section
through the outlet works; a block above the title block showing the reservoir
area and capacity curves, and discharge curves of the spillway and outlet works;

Reinforcement
Design
Diagram

BASIC STRUCTURALSTEEL

DESIGN DRAWINGS

LIGHTING INSTALLATION PLANS

Plan Views

Mounting Dimensions

Fixture Wire

WIRING DIAGRAMS FOR SWITCHBOARDS

PRELIMINARY
ESTIMATE
DRAWINGS

1.21A

General Plan
& Sections--
Location on
Drawing

Area & Capacity

Location Map

Exploratory
Borings

Vicinity Map

TION

DRAWINGS

SPECIAL STANDARDS AND INSTRUCTIONS (Continued)

a small general location map; and logs of all investigational borings available, with locations of borings shown on the general plan. A cross section showing the top of the dam in greater detail may be added if space is available.

A. The general plan should be located on the left side or upper left-hand
corner of the drawing and the direction of streamflow should preferably be
toward the top of the drawing or otherwise to the right or between the top
and right sides. All sections should be such that the direction of streamflow
is from left to right.

B. The block including the area and capacity curves should be rectangular in outside dimensions with the height about two-thirds of the width.

C. The general location map should preferably be located in the upper right-hand corner of the drawing, always with the north direction at the top of the map.

D. Exploratory borings should be shown by profile sections showing relative elevations of the borings.

E. A vicinity map should be included if necessary to show the location of earth embankment materials or concrete aggregate materials proposed to be used in construction.

SPECIFI- .22 Specification and construction drawings should include the general plan or CATION & layout drawing; this should show all features and details required in the preCONSTRUC- liminary estimate drawings, but in greater detail and with greater accuracy depending upon the data available. Plans and horizontal sections of all drawings of dams and other hydraulic structures should be prepared so that the direction of streamflow is toward the top of the drawing. Profiles and profile sections parallel to streamflow should be located so that direction of flow is from left to right. Developed elevations and cross sections parallel to the axis of the dam should be prepared as looking downstream, unless an exception is definitely warranted.

ILLUS-
TRATIVE

DRAWINGS, .23
MAPS, &
CHARTS

Drawings for
Reproduction

as

Illustrations

Architectural
Drawings

Perspective
Maps

In addition to the types of drawings and maps discussed in the foregoing
paragraphs, there is a requirement for a variety of illustrative and pictorial
drawings, charts, and maps.

A. Drawings for reproduction as illustrations for publications should be
specially prepared so they will be uniform, legible, and neat appearing
when printed. All unessential details should be omitted to prevent a
"cluttered up" appearance when the drawings are reduced considerably
yet portray the main idea to the reader without requiring lengthy study of
the drawings. Letters should be large enough to allow reduction, and they
should not be crowded. The weights of lines and lettering should be deter-
mined, considering reduction and dimensions of the drawings after printing,
so as to be legible, but not disproportionate with the drawing's appearance.
Care should be taken in placing lettering at the sides of drawings to ascer-
tain that it will not appear upside-down when the illustrations are finally
printed. Borders should be used only if they improve the appearance of
the drawing. Borders should not be used with graphs, as they appear
superfluous and tend to be confused with the lines of the graph.

B. Architectural drawings and pictorial representations of proposed structures
are desirable in selecting the style of structure, its arrangement, and
setting. Such drawings are also useful in describing projects at Congres-
sional hearings and to various citizens' and water users" organizations.

C. Perspective maps have proved useful in illustrating transmountain
diversions and the layout and operation of projects, as well as for their
general public relations value.

1.23D

SPECIAL STANDARDS AND INSTRUCTIONS (Continued)

D. Pictorial graphs and charts, making liberal use of color, are often useful in presentation of reports, and in public relations work.

The value of the above types of drawings depends on their effective use in connection with the subject under consideration. However, the principles of accuracy and simplicity should not be sacrificed in an attempt to obtain spectacular effects. Standard references are available in most technical libraries treating in detail the subjects of perspective maps, charts, and graphs.

REVISIONS

.24 Responsibilities and administrative procedures for revising Bureau drawings
are given in Chapter 2.5, Drawings, of Volume X. The following technical
procedures apply:
and

ked

Pictorial

Graphs &
Charts

PROCEDURE

اے اور الله

A. When a drawing is revised, the tracing should be marked "Revised,"
including the date of revision, the initials of the person making the revision,
and the station number of the office (if other than the Branch of Design and
Construction) at which the revision is made. (Station numbers are listed in
Appendix I to Chapter 13.2, Volume I). This revision notation should be
placed in a vertical position at the left-hand side of the title block as indi-
cated on Figures 2 and 3. Revision blocks should not show on drawings
before they have been approved. All changes should be encircled in freehand
with a soft (preferably 2B or 3B) black pencil on the back of the revised
tracing, as shown on Figure 21. These marks should be removed promptly
from the tracing after the first printing of the revision.

B. A new drawing that is prepared to supersede or replace a previous drawing
should be marked "This drawing supersedes Drawing No.
inserting the proper number in ink. The person making the drawing should
place this notation in a conspicuous position near the title of the drawing.
On tracings the notation should be placed just above the title block as shown
on Figure 4. The new tracing should be assigned a new drawing number.
The old tracing should be marked "This drawing superseded by Drawing
No.

Marking

Revised

Drawings

Marking Replacement Drawings

TRACINGS

.25 Every drawing other than an illustration for publication or report should bear the initials of the designers, draftsmen, tracers, and checkers directly concerned in its preparation. If the use of initials causes confusion as to the identity of the individual concerned, names should be substituted.

On tracings to be made from temporary or other drawings that have been previously and properly autographed, the tracer may substitute the lettered names of the signers in lieu of obtaining duplicate autographs.

.26 In checking and making corrections on drawings and tracings, the following
procedure shall be strictly observed:

A. As soon as a drawing is traced, the chief draftsman shall obtain a white
(blackline) checking print of the drawing and return the print together with
the original drawing to the section from which it originated. The chief
draftsman will normally retain the tracing.

B. The drawing should then be checked and all required corrections and additions should be made on the checking print. Corrections should normally be made or noted in red pencil; however, where this does not provide a satisfactory means of showing corrected or new details, these details should be neatly shown in black pencil, preferably on the original drawing, with reference on the checking print to the changes, and a red circle drawn around them. Check marks on the checking prints should be in blue pencil provided that where two distinctive colors are desired to be used as when Rel.35 1/29/51

INITIALS

CHECKING DRAWINGS & TRACINGS

The Checking
Print

Marking Corrections

1.26C

Blueprints for Checking

Drawings & Tracings after Checking

TRACINGS (Continued)

checked by the designer and the checker, the designer should use blue
pencil and the checker should use yellow pencil for marking through data
checked as "correct," and green pencil for incorrect data which is to be
deleted. All check marks should be neat and small. Summarizing, use red
for corrections and additions; blue for checking; yellow for double checking;
and green for deletion.

C. The use of blueprints for checking prints ordinarily should be avoided, but
when used for this purpose corrections should be made in yellow pencil and
check marks in white pencil. Red, blue, or green pencils should not be used
on blueprints.

D. After checking, the checking print and the original drawing, if required, should be returned to the chief draftsman. When the tracing is corrected, completed, and back-checked against the checking print, all the drawings and the tracing shall be returned to the section from which they originated.

METHODS AVAILABLE FOR REPRODUCING DRAWINGS

GENERAL .27 The following information is presented in order that engineers and draftsmen may know the methods which are available for reproducing drawings, and for their guidance in requesting reproduction work. Reproductions of drawings, including graphs and tabulations, at the same scale as the original drawings may be made by means of linen or paper tracings of the originals, from which contact prints are made on blue, black, or brown processed paper; or reproductions may be made at the same or different scales by one or another of the more elaborate photographic processes in which the camera is employed.

Blueprints

Black & White (BW)

or Blackline

Prints

Ozalid Prints

Vandyke
Prints

A. Blueprints (white lines on a blue background) are prepared directly from
linen or paper tracings or from other positive transparencies. The blue-
print is inexpensive, not easily soiled, deteriorates slowly, and may be
quickly produced. Its only objectionable features are that it fades with
considerable exposure to sunlight, and the wetting and drying involved in
the reproduction process results in a print that is not very accurate for
scale work. The blueprint was long popular for construction drawings and
prints, but the blackline print is now extensively used for this purpose.

B. Black and white (BW) or blackline prints are made directly from linen or
paper tracings or from other transparent originals. The prints have black
lines on a white background; and the distortion is very slight due to the
fact that the prints are not immersed in a water or chemical bath, as is
the case in many other printing processes. The black and white print is
popular as a check print since the white background facilitates pencil
notations, computations, and corrections. These prints are also frequently
used for copies of drawings in preliminary reports. Good black and white
prinis can also be used for photographing. The BW print is not a permanent
print, as the background turns to a dark tan with age. It is stained by
photographic chemicals, and because of this it should not be bound or filed
in direct contact with photographs.

C. The ozalid print (colored lines on a white background) is usually used when
a print to accurate scale is required, as the prints are as near exact scale
as the cloth or vellum original or tracing. The white background permits
the making of notations or the inclusion of coloring. The usual ozalid has
purple lines and does not photograph well; the blackline ozalid prints are
most satisfactory for photographing or photostating. A translucent original
is required.

D. The negative vandyke print (white translucent lines on a brown background, with reversed lettering) is used as a means of obtaining blueline prints, thick and thin brownline prints, and reproduced tracings on cloth. From a