ML20115D965
| ML20115D965 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 04/13/1985 |
| From: | Ellis J Citizens Association for Sound Energy |
| To: | Bloch P, Jordan W, Mccollom K Atomic Safety and Licensing Board Panel |
| References | |
| CON-#285-592 OL-2, NUDOCS 8504190157 | |
| Download: ML20115D965 (16) | |
Text
5. %,
C A S E
=2 (CITIZENS ASSN. FOR SOUND ENERGY)
._ gp no April 13,1985 (Mailed April 14, 1985)
U
'M b
Administrative Judge Peter B. Bloch U. S. Nuclear Regulatory Commission Washington, D. C.
20555 gc i.mt w 00;E. s SEFVICi.
MU Dr. Kenneth A. McCollom, Dean Division of Eng(neering, Architecture & Technology Oklahoma State University Stillwater, Oklahoma 74074 Dr. Walter H. Jordan 881 W. Outer Drive Oak Ridge, Tennessee 37830
Subject:
In the Matter of Texas Utilities Electric Company, et al.
(Comanche Peak Steam Electric Station, Units 1 and 2)
Docket Nos. 50-445.-1 and 50-446-1 CASE's 8/6/84 Answer to Applicants' Motion for Summary Disposition Regarding Consideration of Friction Forces in the Design of Pipe Supports with Small Thermal Movements Gentlemen:
During the meeting on 3/23/85 between the NRC Walsh/Doyle Allegation Team, CASE, and Applicants, it was brought to CASE's attention that there was some question on our position regarding certain code requirements discussed in subject Answer.
In response to questions by NRC's John Fair, Mark Walsh has supplied Mr. Fair with the attached letter which further clarifies our position.
We are attaching it for the Board's information also.
Respectfully submitted, Ma rs.) Juanita Ellis, President ec: Service List 8504190157 850413 PDR ADOCK 05000445 G
PDR S
C A S E==
(CITIZENS ASSN. FOR SOUND ENERGY)
April 12,1985 (Mailed April 14, 1985)
Mr. John Fair c/o Mr. Vincent Noonan Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Subject:
In the matter of Texas Utilities Electric Company, et al.
(Comanche Peak Steam Electric Station, Units 1 and 2)
Docket Nos. 50-445-1 and 50-446-1
Dear Mr. Fair:
During the meeting of 3/23/85 in Arlington, Texas, between CASE, the NRC Walsh/Doyle Allegation Team, and Applicants, you asked me what my concerns were between the AISC Code and the ASME Code with Regulatory Guide 1.124 (see 3/23/85 transcript, about 1/3 or so into the meeting).
In my opinion, there is virtually no difference between the AISC Code and the ASME Code with the Reg Guide when they are discussing friction. The Applicants' position (and, it appeared to me, your position?) was that there was an allowable increase in stress by three times the normal allowable due to restraint of free-end displacement; the basis given was because of NF 3231.1.
(See Affidavit of John C. Finneran, Jr., attached to Applicants' 5/16/84 Motion for Summary Disposition Regarding Consideration of Friction Forces in the Design of Pipe Supports With Small Thermal Movements, beginning bottom of page 4.)
In particular, the. Applicants state that they are allowed to increase the allowables due to "the thermal growth of the pipe, i.e., effects which result from the restraint of free-end displacements... combined with 1
-those mechanical' loads ~... " (emphasis added). As Jack Doyle and I stated in our Affidavit, "This defies all logic." (See page 7, first paragraph, Affidavit-of. CASE Witnesses Jack Doyle and Mark Walsh, attached to CASE's 8/6/84 Answer to Applicants' Motion for Summary Disposition Regarding Consideration of Friction Forces'in the Design of Pipe Supports with Small Thermal Movements.)
The Applicants' position (to the best'of my recollection), prior to
'this Motion for Summary Disposition, did not include their present j
interpretation of NF 3231.1.
(The Staff also did not include.this interpretation in its Proposed Findings.) 'Since the 3/23/85 meeting, I have reviewed the current ASME Code. Of particular interest was this area of i
friction.
-Prior to Applicants' Motion for Summary Disposition, I believed that the Applicants treated the stresses due to constraint of free-end displacement from the pipe as a mechanical load.
In your off-the-record discussion with me at the March 23 meeting, you indicated that portion of the code on which the Applicants relied for the three-times-allowable
. increase and, as I pointed out, one could also interpret that paragraph on constraint of free-end displacement to also include the intended direction i
of restraint.
If my memory serves me correctly, you stated that you would j
not allow Applicants to use that paragraph in that way.
During my review of the latest ASME Code, I was interested in what ASME's present position is regarding' constraint of free-end displacement.
The'following summarizes what I found, all of which is from the ASME Code,
-Division 1, Subsection NF, 1983 Edition, July 1, 1983, as currently revised
-(I'm attaching copies of applicable pages):
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2
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"NF-3121.2 Primary Stress. Primary stress is any normal stress or shear stress developed by an imposed loading which is necessary to satisfy the laws of equilibrium of external and internal forces and moments. The basic characteristic of a primary stress is that it is 4
not self-limiting. ' Primary stresses which considerably exceed the yield strength Sy will esult in failure or, at least, in gross distortion. A thermal stress is not classified as a primary stress. A
-genera 1' primary: membrane stress is one which is so distributed in the support that no redistribution of load occurs in the support as a
-result of yielding. Examples of primary stress are general membrane stress in aJcircular cylindrical shell due to a uniformly distributed axial load, and bending stress in a cantilver beam due to a normal end load. In addition to the above, for piping and component supports, stresses induced in the support by restraint of free end displacement
-[NF-3111(e) and (f)] and anchor motion of piping are considered primary stresses." -(Emphasis added.)
l Table NF-3131(a)-1 REFERENCE PARAGRAPHS FOR PROCEDURES FOR DESIGN OF COMPONENT SUPPORTS AND PIPING SUPPORTS indicates that for Linear type supports, designed by analysis, for Classes 1, 2, and 3, the following paragraphs apply: NF-3320 and NF-3623, NF-3350 and NF-3653, and NF-3360 and NF-3653, respectively.
NF-3350 requires that supports be in accordance with NF-3320 (which is the same as for Class 1 supports).
1 l
"NF-3321.1 Design and Service conditions i.
.(a) Except as otherwise provided in this Subarticle, all items of the structure shall be so proportioned that the stress, ksi, for Design and Level A Service Limits, shall not exceed the values of NF-3322. For Level B, C, and D Service Limits, allowable stresses may be increased by the factors shown in Table NF-3523(b)-1 and NF-3623(b)-1. Bearing type stress limits are excluded-from rules for Level D Service Limits."
Table NF-3523(b)-1 lists the stress limits for all classes of linear type supports designed by analysis. Under the stress category of Primary Stresses, it refers to Note 5, which states:
3
w
"(5) For Service Levels A, B, C, and D, stresses induced on the supports by restraint of free end displacement and anchor motions of piping shall be considered as primary stresses." (Emphases added.)
In summary,' Applicants' position as indicated in their Affidavit that they are allowed to increase the allowables by three times due to the restraint of free-end displacement is not in accordance with the'present ASME position. I do not believe that this is a change of position by ASME, but is a clarification of what ASME intended all along. Applicants have misinterpretted the ASME Code requirements, which are just as restrictive as (and virtually identical to) the AISC Code requirements.
Sincerely, Mark A. Walsh Attachments cc: Service List 1
4
=
N ASME BOILER AND PRESSURE VESSEL CODE
(
AN AMERICAN NATIONAL STANDARD O
/
SECTION III C
Rules for Construction of Nuclear Power Plant Components DIVISION 1 SUBSECTION NF Component Supports 1983 EDITION 1
JULY 1,1983 j
C ASME BOILER AND PRESSURE VESSEL COMMITTEE SUBCOMMITTEE ON NUCLEAR POWER THE AMERICAN SOCIETY OF MECHANICAL. ENGINEERS United Engineering Center 345 East 47th Street New York, N.Y.10017
N ARTICLE NF-3000 DESIGN NF-3100 GENERAL DESIGN maximum temperature limitations specified elsewhere
{
REQUIRE 31ENTS in this Subsection.
NF-3110 LOADING CRITERIA NF-3112.2 Design Mechanical Loads. The specified NF-3111 Loading Conditions Design Mechanical Loads shall be established in accordance with NCA 2142.l(c), and shall include all The loadings that shall be taken into account in loads from the component or piping acting on the designing a piping or component support include, but support.
are not limited to, those in (a) through (g) below:
-(a) weight of the piping or component and normal NF-3113 Service Conditions contents under operating or test conditions, meluding loads due to static and dynamic head and fluid flow Each service condition to which the piping or effects; component may be subjected shall be categorized in (b) weight of the piping or component support; accordance with NCA 2142, and Service Limits
(.)
(c) superimposed loads and reactions induced by
[NCA-2142,2(b)] shall be designated in the Design the supported system components:
Specification in such detail as will provide a complete (d) dynamic loads, including loads caused by earth-basis for design in accordance with this Article.
quake and vibration; (c) effects from component or piping thermal ex-NF M
'I'd Mim pansion:
(f) anchor and sepport movement effects; (In course of preparation.)
(g) environmental loads such as wind and snow loads.
NF-3120 DESIGN CONSIDERATIONS NF-3112 Design Loadings NF 3121 Terms Relating to Design by Analysis The Design Loadings shall be established in accor-NF-3'121.1 General Considerations
(-
dance with NCA-2142.1 and the following subpara-(a) Terms that are common to the design by stress graphs.
analysis of Plate and Shell Type, Linear Type, and NF-3112.1 Design Temperature. The specified De-Standard Supports are defined in NF-3121.2 through NF 3121.16 below.
sign Temperature sha;l be established in accordance with NCA.2142.l(b). The metal temperature shall be (b) Terms unique to the design by stress analysis of determmed by computation using accepted heat trans-Plate and Shell Type Suppor's are defined in NF 3212.
fer procedures or by measurement from equipment in (c) Terms unique to the design by stress analysis of service under equivalent operating conditions. In heu Linear Type Supports are defined in NF-3313.
of heat transfer analysis or measurements, the compo.
NF-3121.2 Primary Stress. Primary stress is any nent or piping Design Temperature may be used. In normal stress or shear stress developed by an imposed no case shall the temperature at the surface of the loading which is necessary to satisfy the laws of metal exceed the maximum temperature listed in equilibrium of external and internal forces and mo-Tables I l!.0, I 12.0, and I.13.0, or exceed the ments. The basic characteristic of a primary stress is 39
N NF-3121.2-NF-3121.15 SECTION III, DIVISION I - SUBSECTION NF 1983 Edition that it is not self-limiting. Primary stresses which distributed w! equal to the average of stress across considerably exceed the yield strength S,will result in the thickness of the sectiva under consideration.
.(
i
. failure or, at least, in gross distortion. A thermal stress is not classified as a primary stress. A general primary NF-3121.8 Bending Stress. Bending strea is the membrane stress is one which is so distributed in the variable component of normal stress. The variation support that no redistribution of load occurs in the may or may not be linear across the thickness.
support as a result of yielding. Examples of primary NF-3121.9 Total Stress. Total stress is the sum of stress are general membrane stress in a circular the primary and secoadary stress contributions. Rec-cylindrical shell due to a umformly distributed axial ognition of each of the individual contributions is load, and bending stress m a cantilever beam due to a essential to establishment of appropriate stress limita -
normal end load. In addition to the above, for pipmg tions.
and component supports, stresses mduced in the support by restraint of free end displacement [NF-NF 3121.10 Critical Buckling. Critical buckling 3111(e)and(f)] and anchor motion of piping are occurs when a support is loaded to a state at which an 7
considered primary stresses.
infmitesimal additional load or disturbance causes the
(
NF 3121.3 Secondary Stress. Secondary stress is a support to change from an equilibrium condition.lo normal stress or a shear stress developed by the one ofinstability.
constraint of adjacent material or by self-constraint of NF-3121.11 Thermal Stress. Thermal stress is a the structure. The basic charactenstic of a secondary self-equilibrating stress produced by a nonuniform stress is that it is selflimiting. Local yieldmg and distribution of temperature or by differing thermal minor distortions can satisfy the conditions which coefficients of expansion. Thermal stress is developed cause the stress to occur, and failure from one in a solid body whenever a volume of material is application of the stress is not to be expected. An prevented from assuming the size and shape that it example of secondary stress is bending stress at a gross normally would under a change in temperature.
structural discontm.nty.
Evaluation of thermal stresses in the support is not NF-3121.4 Peak Stress. Peak stress is that incre-required by this Subsecuon.
NF-3121.12 Free End Displacement. Free [nd
(-,
ment of stress which is additive to the primary plus secondary stresses by reason oflocal discontinuities or disp acement consists of the relative motions that l
local thermal stress, including the effects, if any, of stress concentrations. The basic characteristic of a w uld occur between an attachment and connected peak stress is that it does not cause any noticeable structure or equipment if the two members were distortion and is objectionable only as a possible separated and permitted to move.
source of a fat! ue crack or brittle fracture. A stress NF-3121.13 inchor Point Motion Stress. Anchor 7
which is not highly I.alized falls into this category if point motion r tr:sses are those stresses resulting from it is of a type which cannot cause noticeable distortion.
the differential motion of piping or component support Evaluation of peak stresses is not required by this points. An example is differential building settlement.
Subsection.
NF-3121.14 Gross Structural Discontinuity. Gross NF 3121.5 Normal Stress. Normal stress is the structural discontinuity is a geometric or material component of stress normal to the plane of reference.
discontinuity which affects the stress or strain distri-('
This is also referred to as direct stress. Usually the bution threugh the entire th'ickness of the member.
distribution of normal stress is not umform through Gross discontinuity type stresses are those portions of the thickness of a part, so this stress is considered t the actual stress distributions that produce net bend-be made up in turn of two components, one uniformly ing and membrane force resultants when integrated distributed and equal to the average value of stress through the thickness. Examples of gross structural across the thickness under consideration, and the discontinuities arejunctions between parts of different other varying from this average value with the diameters or thicknesses and flange-to-shell junctions.
location across the thickness.
NF-3121.15 Limit Analysis - Collapse Load. The NF-3121.6 Shear Stress. Shear stress is the compo-methods of limit analysis are used to compute the nent of stress tangent to the plane of reference.
maximum load or combination of loads a structure j
NF-3121.7 Membrane Stress. Membrane stress is made ofideally plastic (nonstrain. hardening) material i
the component of normal stress which is uniformly can carry. The deformations of an ideally plastic 40
m _-
_w..____
\\
1983 Edition NF-3000 - DESIGN NF-3144-NF-3212.1 TABLE NF-3131(a)-1 R2FERENCE PARAGRAPHS FOR PROCEDURES FOR DESIGN OF
(-
COMPONENT SUPPORTS AND PIPING SUPPORTS Type and Plate and Shell Linear Class of Design by Weld Experimental Load Design by Weld Experirnental Load Support Analysis Bolting Joint Analysis Rating Analysis Bolting Joints Analysis Rating Co,qnnent Class 1 NF-322: NF-3225 N F-3226 N F-3270 N F-3280 N F-3320 NF-3324 NF-3324 NF-3370 NF-3380 N F-3522 N F-332: N S-3526 N F-3523 NF-3525 N F-3526 Class 2 N F-3250 N F-3255 N F-3256 N h3270 N F-3280 N F-3350 N F-3324 N F-3324 N F-3370 NF-3380 and MC N F-3552 N F-3555 NF-3556 N F-3553 N F-3555 N F-3556
[ Note (1)!
(
Class 3 N F-3260 N F-3265 N F-3266 N F-3270 N F-3280 NF-3360 NF-3324 Nf' 3374 NF-3370 NF 3380 N F-3552 N F-3555 N F-3556 N F-3553 NF-3555 N F-3556 Piping CI' ass 1 N F-3220 NF-3225 N F-3226 N F-3270 N F-3280 N F-3320 NF-3324 N F-3324 N F-3370 N F-3380 N F-3622 N F-3625 NF-3626 N F-3623 N F-3625 N F-3626 Class 2 N F-3250 NF-3255 N F-3256 NF 3270 N F-3280 N F-3350 NF 3324 N F-3324 NF-3370 N F-3380 N F-3652 N F-3655 NF-3656 NF 3653 N F-3655 N F-3656 Class 3 N F-3260 NF 3265 N F-3266 N F-3270 N F-3280 N F-3360 NF-3324 N F-3324 N F-3370 N F-3380 N F-3652 N F-3655 N F-3656 N F-3653 N F-3655 N F-3656 Standard j
Class 1 N F-3220 N F-3225 N F-3226 N F-3270 N F-3280 N F-3320 NF-3324 N F-3324 NF-3370 - NF 3380
[ Note (1ll N F-3422 N F-3425 N F-3426 N F-3423 N F-3425 NF-3426 Class 2 NF-3253 N F-3255 N F-3256 N F-3270 N F-3280 NF 3350 NF-3324 NF-3324 N F-3370 N F-3380 and MC N F-3452 f4 F-3455 N F-3456 N F-3453 N F-3455 N F-3456
[ Note (1)]
Class 3 NF 3260 NF 3265 NF-3266 N F-3270 NF-3280 N F-3360 N F-3324 N F-3324 N F-3370 N F-3380 N F-3452 N F-3455 N F-3456 N F-3453 N F-3455 N F-3456 NOTE:
(1) Supports for Class 2 vessels designed to NC-3200 shall be designed in accordance with Class 1 requirements.
' (-
NF-3143, according to whether they are Plate and shear s' tress theory; for Class 2,3, and MC Plate and Shell Type or Linear Type Standard Supports.
Shell Type Supports, it is the maximum stress theory.
NF 3212 DeAnttions NF.3200 DESIGN RULES FOR PLATE AND SiiELL 'lTPE SUPPORTS Terms used in the design of Plate and Shell Type UPPortdy stress analysis ardennWn W 3121 and NF-3210 GENERAL REQUIREMENTS in NF-3212.1 below.
NF-3211 Basis for Determining Stresses in NF 3212.1 Stress Intensity.8 Stress Intensity is an by Analysis dermal as twice the maximum shear stress. The stress The theory of failure used in the rules of this Subsection for combining stresses for the design of 8This dennition of stress latensity is not related to the deAnition of Class 1 Plate and Shell Type Supports is the maximum stress intecity applied in the neld or tracture mechanics.
43
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j.r.m* W[,M'f'NF.300(I '- DESIGN
%e ~.,". t%n, - 3 y
Kp.9.'
p J O.? -.. M NF-3313.1-NF.3321.1 NM.1 5M.
i. 4 W :. ^...R.w Q, W. ' 1983 Edition q,
9[F -
1@f0
.,1 *,Q(
WN u, T,= initial clamping force per... bolt, Ib (not to,'~ ' '
. braced against twist or lateral displacement of 59 i
M....- v.
y M
..Oc.. exceed.115,000 A,, where A, is the tensile." T.
the compression Range,in.
P'
.A*i d....x..M[
stress area of the bolt, sq in.') >
' Jc.] '
$w,l 4M@'; V.= shear produced by required
. =for columns, actual unbraced lensth of mem-
- j,]1
'.. ber, in., unsupported length of lacing bar, in.
]'
ding @,W?
I,= actual unbraced length in plane of. bending, p
Q.I dll.
(
X'M.&
ultimateload, kips gi in.-
t "%P >
-- W Q p. ; Y= ratio of yield stress of web steel to yield stress-. "
~ ~
MU'.75I.'..$. (ofstisenersteel "M,.
^;&,W 1,,= critical unbraced length adjacent to plastic s '.. 7,,h4 hQ hinge,in..
M y Z= plastic section modulus for'ixis of bending,' S i.i, s
7.W".
Qp*
m = number of shear planes per bolt M.y -.
gi
'.1,7.Q in.
,;y-7,'.;qWg.f;. - a= clear distance between transverse stiffenerr;. D n= number of bolts in thejoint
- 12;_
.,rg
.?
dimension parallel to the direction of stress, r r= governing radius ofgyration,in. im. -
- de Wf' r = radius of gyration about axis of concurrent s.Ti.
Table NF-3332.3 1, in.
. g.
&. l h
a'= distance required at ends of welded partialj bending,in..
j
,.i.j@
]
t W'
?7 length cover plate to develop stress, in.
40 r,= radius of gyration of a section comprising the j
b= actual width of'stisened and unstisenedy -
.. compression. Sange plus one. third of the Qt Y
'W<.
- ' ~
>f.N...
compression elements yrte.
w @u.... -
compression web area, taken about an axis in
. !.V.
4.
.. w w..
= dimensions normal to the direction of stress,;,,
the plane of the web,in.
@n
.m
.y
-?pc.a e+
Table NF-3332.31,in. ' %
@fg.
r,= radius of gyration of a member about its. weak ig
.m.
'hI DdN,W*.+S " b,=esective width of stiffened _, compression. ele" ?! -
", axis,in. t7..J2 ;.1
. 3@M'.A S$t[,h
- IJg.g.;
ment, in.. '
. 3@ >.
1sy'
s=longitudmal center.to-center spacing (pitch)
- y 4a M""
P:c i ~ hji'M of= nange width of rolled beam or plate girder,in.
of any two consecutive holes,in.
M;. [ EN,.d=d*Pth of beam or girder M
M; t= girder, beam, or column web thickness, in.;
thickness of a connected part,in.
2#
M. J '" w.P.'". =diasueter of roller or rocker bearing ' 1 m
f I..
'U.1 1, = nominal diameter of fastener, in.
=walliWirnean of a tubular member,in.
t = thickness of beam Range or moment connec-
'... d<= column web depth clear of Allets,in..
! ~.,..a.. i._'t... e= horizontal displacement, in the diraction of tion plate at rigid beam to column connec-6
%JD;
.:/
- i +. -
the span, between top and bottom of simply tion,in.
+
I W(P t = Range thickness,in.
h supported beam at its ends,in.
f f= axial compression stress on member based on t,=thkkeess of thinner part joined by partial 4 -3, -
,. g.c;,
efective area, ksi
.Q penetration groove weld,in. ~
[$. " m ;c~.
7m x= subscript relating syml,ol to strong axis bend-f,= computed axial stress, ksi ^
ing n*
o
~,..
g.;
f,= computed bending stress, kal
;].j,"f,=speci6ed compression strength of concrete, y= subscript relating symbol to weak axis bent!-
' ~ (
3.s.
N-
~
~ a N";
M +.. ?.: -
ksi w C,.:...
. ing
-.--~
dh",' M ff= computed bearing stress, ksi a= ratio of hybrid girder web yield stress to
^
W.1.... [- ;;J ";
f,= computed tensile stress,ksi Sange yield stress 7.UT
~ girf" F:
y.
.~._. f;= computed shear stress, ksi
' A= displacement of the neutral axis of a loaded
$gr'r * ' " ^;&fy if,,= shear between girder web and transverse
. member from its position when the member is 7
e m
'not loaded,in.
. Mb 9 g:
di, N'.'Jyf;'
stiseners, kips /hnear in. of single stisener or en,,1 NF 3313.2 Numbering of Equatio%4 -ns. A separate
- -- ~
N.
-e
.s.
. w.J. e..
Pair or,g; gen,,,
cm"
^ ~ ~ '
av A
.a
" Wim; g= transverse spacing (gage) between successive series of e.quation numbers is used for each paragraph
.a
'O.
4 g-
. m.m holes in line ofstress,in. +. s.,
. m"t.;.U. " h= clear distance between San,g"es of a beam ~or and each series, beginmns with Eq. (1.) w n
m
.. - w was
.Mh:/"'!...
- 3 rm
~#
.M?
e
,J '.'~ - M..-
[.#f 9/f,~.,' '
girder at the section.under investigation, in.
.+
v.e w.
' M..;*J, W
E.J ' k=coeGicient relating linear buckling strength of
'SI-
.D..,
s,
~
Y Je a plate to its dimensions and condition of edge support 4:.
NF 3320 y DESIGN BY LINEAR ELASTIC
=also distance between outer face of column '
ANALYSIS FOR CLASS 1 fg
.Sange and web toe of its Atlet if column is a NF 3321 General Design Requirem ats e.%
4 rolled shape, or equivalent distance if column NF 3321.1 Design and Service Conditions
".: ? '
's a welded shape,in.
i p
b
- k. =stip.caedicient for the particular surface (a) Except as otherwise provided in this Subarticle, 883. '
condition taken ikom Table NF-all items of the structure shall be so proportioned that
. 'l
~-
.I 3324.6(aX4FI O.
the stress, kal, for Design and Level A Service Limits,
~ y
~
l=for beams, distance between cross section shall not exceed the values of NF.3322. For Level B,
- i. '.>. '
j
~;m
.r ms. m' c '[ ' 34,1
-..,.y.
4
,4
.N i *d 4
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. W;;
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NF-3000 - DESIGN NF 3321.1-NF 3322.1 1983 Edition
/
.C, and D Service Limits, allowable stresses may be fasteners, or by a combination of shear alongIplane
~
j increased by the factors shown in Tables NF-3523(b)-
through the fasteners plus tension along a perpendicu-1 and NF-3623(b)-1. Bearing type stress limits are lar plane, on the efective area in resisting tearing excluded from rules for Level D Service Limits.
failure shallbe:
- (b) To avoid column buckling' in compression members, local instability associated with compression F, = 0.30s, (3b) flange buckling in Sexural members, and web buckling in plate girders, the allowable stress shall be limited to The efective area is the minimum net failure surface, two-thirds of the critical buckling stress.
bounded by the bolt holes.
. NF 3321.2 Design for High Cycle Fatigue Condi-(c) Stress in Compression. The allowable stress.in-tion. Design for high cycle fatigue conditions shall be compression shall be as required by (c)(1) through (5) below.
in accordance with the requirements of NF-3330,
. e using the allowable stresses of NF-3322 as modi 6ed by (1) Gross Sections Where K//r Is Les 11an C,.
Sea
- NF 3332.4.
On the gross section of axially loaded compression members whose cross sections meet the provisions of NF-3322.2(d), when Kl/r (the largest efective slen-r e
7 derness ratio of any unbraced segment as denned in NF-3322.4) is less than C,, the allowable stress in NF 3322 Design Requirements for Structural compression shallbe:
1
. Steel Members j
7 NF 3322.1 Allowable Stresses - Design and Imel
{gg _(ggf,) /2C,8))S.
F. =,j 3 + (3(KI/r),,C,),((KI/r),/ sC,,]
A Sonice CondMons f
(a) Stress in Tension. The allowable stress in tension shall be as given in (sXI), (2), and (3) below:
where ses (1) Except for pin-connected and threaded mem-bers,F,shall be:
C, = V2w E/S,
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'8 ~ 0.60S, (l}
(2) Grost Sections Where Kl/r Is Greater Than C,. On the gross section of axially loaded compression
. but not more than 0.5 times S on the efective net members when Kl/r exceed. C,, the allowable stress in compression shallbe:
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(2) For pin-connected membert, using the net 12w'E F. = 23(Kl/r)8 (5)
, F, = 0.455, (2)
V 883 (3) For threaded parts in tension, see NF-(3) Gross Sections Where the Slenderness Ratio 5
Faceeds 12d On the gross section of axially loaded
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. 3324.6(a)(1).
I (6) StressIn SAcar bracing 'and secondary members, when 1/r exceeds 120
- (1) Except as provided in (b)(2) below and NF.
the allowable stress in compression shall be:
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3324.6(a)(3), on the cross-sectional arcs efective in resisting shear:
F., = F,[Eq. (4) or (5)]
(6) 2 1.6-(300'
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F. = 0.40S, (3a)
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'the efective area in resistin's shear of rolled and fabricated shapes may be taken as the overall depth (4) Plate Girder St/feners. On the gross area of U
times the web thickness.
plate girder stireners, the allowable stress in compres-(2) At the beam end connections where the top sion shallbe:
Sange is coped, and in similar situations where failure might occur by shear along a plane through the F. = 0.6&f, (7)
- For decenninesion of eGuetive not area, we NF.3322.8.
eFor this case, K is taken as unity.
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NF-3000 - DESIGN,(
NF-3342.2-NF-3381 "4
1983 Edition dia-n..<
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_ hinge locations to similarly braced adjacent points on (4) Stress in Bolts and Weldt High strength
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- the member or frame shall not exceed the value bolts, SA 307 bolts, and welds shall be proportioned to resist the forces produced at factored load, using
- [ ' ". determined from Eq. (9) or (10), as applicable
stresses equal to 1.7 times those given in NF-3324.6(a)(1) for bolts and Table NF-3324.5(a)-1 for
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m -1,/r, = 1375/S, + 25
.(9) welds. In general, groove welds are preferable to fillet welds, but their use is n6t mandatory.
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when 51.0 > bi'thi, > -0.5 (5) Joints With Painted Contact Surfacez High strength bolts may be used in joints having painted j.2.
contact surfaces when these joints are of such size that i
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1~ I,/r, = 1375/S, (10) the slip required to produce bearing would, pot
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interfere with the formation, at factored loading, of 1^
when - 0.5 a Af'/Af, > -1.0 the plastic hinges assumed in the design.,,
a 1.
2.,
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-lwhere M..,..
N NF-3350 - DESIGN BY ANALYSIS FOR H
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.N'/M,=the end moment ratio, positive when the SJ
,T, segment is bent m reverse curvature and
- CLASS 2 AND MC
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negative when bent in single curvature The design by analysis of Class 2 and' MC supports C*
(2) The provisions of(d)(1) above need not apply shall be in accordance with NF-3320, NF.3330, and J..
, in the region of the last hinge to form, in the failure NF 3340.
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I mechanism assumed as the basis for proportioning a
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f O'._. * ; given member, nor in members oriented wit's their
. DESIGN BY, ANALYSIS FOR 4
. j weak axis normal to the plane of bending. However, in NF-3360 the region of the last hinge to form and in regions not CLASS 3 s
' adjacent to a plastic hinge, the maximum distance
.g The design by analysis of Class 3 supports shall be q
between pomts oflateral support shall be such as t in accordance with NF-3320, NF 3330, and NF.3340.
. satisfy the requirements of Eq. (17), (18), or (19) of NF 3322.l(d)(5), or Eq. (20) or (21) of NF-N,
. - 3322.l(e)(1). For this case, the value off,andf,shall NF-3370 EXPERIMENTAL STRESS
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be computed from the moment and axial force at 7'
- j., factored loading, divided by the applicable load factor.
ANALYSIS (3) Members built into a masonry wall and Component supports of all types may be designed 7-
. having their web perpendicular to this wall can be by experimental stress analysis in accordance with
[j.,.
.,. ' assumed to be laterally supported with respect to their Appendix IL weak axis of bending.
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, ' (e) Connections aw!
(1) General Requirements All connections, the NF-3380 DESIGN BY LOAD RATING
".. { rigidity of which is essential to the continuity assumed NF 3381 Frocedure for Load Rating W83 as the basis for. the analysis, shall be capable of N(v.d.'.Mresisting the moments, shears, and axial loads to The procedure for load rating shall consist of n
9.
imposing a tou11 load on one or more duplicate full Q..*f
- 'y which they would be subjected by the full factored 3, loading, or any probable partial distribution thereof.
size samples for a compdnent support equal to or less Ni.J. ' 2*L.. (2) Corner Connections Corner connections than the load under which the component support t-r p l(haunches) that are tapered or curved for architectural fails to perform its required function. Full size samples
, reasons shall be :,o proportioned that the full plastic. composed of various parts may have each part or a
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- g. bending strength of the section adjacent to the number of parts load rated provided that all parts in
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the load path are either load rated or otherwise 9,
(J) Stigeners Stiffeners shall be used, as required, qualified per NF 3300 or by experimental stress
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' M f to preserve the flange continuity ofinterrupted mem-analysis. When parts are connected by bolting or fj,2 ers at their junction with other members in a welding the connection shall be either load rated or M*
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. i ' continuous frame. Such stiffeners shall be placed in qualific v:1 NF-3225 or NF 3226. Should more than
. pairs on opposite sides of the web of the member one part be load rated in a single load test, then the which extends continuously through thejoint.
load rating equations of NF-3380 shall be evaluated
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1983 Edition NF 3000 - DESIGN NF-M12.1-NF-3423 throughout the travel range. Deviation is the sum of to which they are attached during nondynamic appli-(
kinematic friction and manufacturing tolerance fac.
cation ofload such as that imposed by expansion and tors. Determination of deviation is by load test contraction.
machine and is calculated as follows:
(b) Snubbers shall be carefully applied to ensure that they will perform their intended function without deviation = (maximum reading moving down placing unacceptable loads on the piping system or
- minimum reading moving up) other components.
-t- (maximum reading moving down (c) The Design Specification shall'contain,-M a
+ minimum reading moving up) minimum, the following:
(1) the Design Loadings for loading conditions NF-3412.2 Variable Support Spring Hangers. Vari-and transients, and combinations of loadings for able support spring hang'ers may be used to support which the snubber is designed to accommodate; piping or components at those locations subject to (2) required force, time, and displacement rela-vertical movement due to temperature differences, tionship; where a variability of the supporting force up to a (3) the environmental conditions that the snub-factor of 0.25, a calculated by the following equation, ber willbe exposed to,such as:
can be tolerated:
(a) temperature
(',
(b) Irradiation
- variability factor = (travel X spring rate)/ load (c) corrosive atmosphere l
(d) moisture
-.(a) The variability of the supporting force resulting (c) airborne particles from movement of the piping or component shall be (4) consideration of material characteristics, such considered in the loadings used in the stress analysis of
,3, the piping or component.
(a) compatibility I
(b) Variable support spring hangers shall be pro-(b) stability vided with means to limit misalignment, buckling, and (c) fire resistance eccentric loading and to prevent overstressing of the (d) wear
(,
spring.
(e) aging (c) It is recommended that all hangers employing (J) tests which are required prior to installation.
springs be provided with means to indicate at all times (d) Design of functional members such as intercon-the compression of the spring with respect to the nections, tubing and fittings reservoirs, and now appropriate hot and cold positions of the piping or distributors shall consider the effect of internal pres.
component.
sure, thermal expansion, and vibration loading.
NF 3412.3 Hanger Rods. Design loads for threaded hanger rods shall be based on the root area of the threads. In no case shall hanger rods less than % in.
NF 3420 DESIGN BY ANALYSIS FOR diameter be used for supporting pipe 2 in. and smaller, CLASS 1 or less than % in. diameter rod for supporting pipe 2%
NF 3421 General Design Requirements in. and larger. Pipe, structural shapes, or bars may be
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shapes, etc., shall be designed to perndt the free accordance with the requirements of NF 3420 using used instead of hanger rods. Hanger rods, structural The design of Class 1 Standard Supports'shall be in movement of piping as indicated in the thermal stress one of the design procedures indicated in Table NF.
analysis. The possibility of moment loading of hanger 3131(a) 1 for Class I construction.
rods or shapes as a result of pipe motion shall be considered and avoided unless the support is spec.
NF.3422 Design of Plate and Shell Type ifically designed for such loading.
Standard Supports NF 3412.4 Snubbers (a) Snubbers may be incorporated in.the system The requirements of NF 3200 shall be met.
design to accommodate Design Mechanical Loads or conditions of a vibratory or dynamic nature. Snubbers NF 3423 Design of Linear Type Standard may be attached to a piping or component to protect it Supports against dynamic type loading. Snubbers shall allow (j
essentially free movement of the piping or component The requirements of NF.3300 shall be met.
83
NF 3425-NF 340 SECTION lit, DIVISION 1 - SUBSECTION NF 1983 Edition NF 3425 Design of Bolting NF-3426)2 Design Stress Intensity and Allowable Stress Limits for Welded Joints. The limit of design The requirements of NF 3225 and NF-3324.6 shall stress intensity or of allowable stress for welded joints net.
for Standard Supports shall not exceed the applicable design stress intensity value or allowable stress value NF-3426 Design of Welded Joints for the base metal being joined. In accordance with NF-3222 or NF-33tl, temperature differences be-NF 3426.1 Permissible Types. The permissible tween the pipmg or component and its support and, types ' f welded joints for Standard Supports shall be where applicable, expansion. or contraction of a o
as stipulated in NF 3226.1 and NF 3324.5(a). Figure C mPonent or pipmg produced by internal or external NF 3426.1 1 illustrates additional werd joints allowed Pressure shall be considered-for Standard Supports as described in (a) through (d) below:
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Ss4 (a) fdlet welded joints', Fig. NF 3426.11 sketches (a 1)and(a 2);
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(b) fillet welded joint between the edge of a plate NF 3450 DESIGN BY ANALYSIS FOR and the end surface of a closed tubular section, closed CLASS 2 AND MC formed section, partially closed tubular section or partially closed formed section, sketches (b) and (d).
NF 3451 General Design Requirements 12 addition, weld joints (b) and (d) may be used only if The design of Class 2 and MC Standard Supports-the lengths of the respective legs of the fillet weld are shall be in accordance with the requirements of NF-equal to the exposed thickness of the plate and she!!
3450 using one of the design procedures indicated in elements. Partially closed tubular sections or partially Table NF 3131(a) l.
elosed formed sections and the total length of thcar respective welds shall encompass a minimum of 270 1
deg. of the circumference and provide symmetrical NF 3452 Design of Plate and Shell Type loadings on closure plates; Standard Supports (c) Allet welded joint between the edge of a plate The requirements of NF 3200 shall be met.
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and the end surface of a closed tubular section, closed formed section, partially closed tubular section or partially closed formed section, sketches (c) and (f).
NF 3453 Design of Linear Type Standard a
Partially closed tubular sections or partia!!y closed Supports formed sections and the total length of their respective The requirements of NF 3300 shall be met.
welds shall encompass a minimum of 270 deg. of the circumference and provide symmetrical loadings on closure plates; NF 3455 Design of Bolting Ws3 (d) partial or full penetration groove welded joints The requirements of NF.3225 and NF 3324.6 shall between the edge of a plate and the end surface of a closed tubular section, closed formed section, partially closed tubular section or partially closed formed y
section, sketches (e 1) and (e 2). Partially closed NF 3456 Design of Welded Joints
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tubular sections or partially closed formed sections The requirements of NF 3426 siiall be met, except and the total length of their respective welds shall that for groove-welded and fillet welded Tjoints, the encompass a minimum of 270 deg. of the circumfer-welds may be intermittent instead of continuous.
ence and provide symmetrical loadings on closure plates. The use of the welded joints shown in sketches (b), (c), (d), (e 1), (e-2), (f), (g), and (h), is limited to housings for spring encapsulation of Standard Sup-e 460 N W AWSN M Ws3 (e) full penetration groove welded joint, sketch (g).
3 between a plate and the end surface of a closed tubular section or closed formed section; The design of Class 3 Standard Supports shall be in Ws3
(/) partial penetration groove welded joint, sketch accordance with the requirements of NF 3450, using f
(h), between a plate and the end surface of a closed one of the design procedures indicated in Table NF.
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tubular section or closed formed section.
3131(a) l.
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t NF 3580-NI' 3612 SECTION HI, DIVISION 1 - SUBSECTION NF 1983 Edition
'i-S33 TABLE NF-3523(b)-1
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ELASTIC ANALYSIS STRESS CATEGORIES AND STRESS LIMIT FACTORS
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'I' FOR CLASS 1,2,3, AND MC LINEAR. TYPE SUPPORTS DESIGNED BY ANALYSIS-COMPONENT SUPPORTS Stress Limit Factors for Loading Categories [ Note (1)J i.
Service Level Service Level 8 Service Level C Service Level D Test Stress Category Design A
[ Note (2)]
[ Note (3))
INote (3))
Loadings Primary Stresses 4 = 1.p-K.
= 1.0 Ks, = 1.33 K.
= 1.5 Ke = 2.0 K. = = 1.3 3 (Note (5)]
.' 4
=1.0 4 = 1.0 -
p 4 = 1.33 4 = 1.5 K,
= 2.0 4 = 1.33 (Note (4)1 (Note (4)]
[No'e (4))
(Note (4)]
K e = 1.0 Ken = 1.0 Kee = 1.33 4e = 1.5 Ken = 2.0 Kee = 1.33 e
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but stress s but strus s but strns s but strus s
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% of critical
% of critical
% of critical
% of critical '
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buckling stress buckling stress buckling stress buckling stress l
Primary Plus Secon-Evaluation is required for c'ritical buckling for all loading categories. The requirements of this Subarticle shaft be met dary Stresses
. for this evaluation.
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Peak Stresses Evaluation not required.
NOMENCLATUR E:
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K. = stress limit factor applicable tr the Design allowable tensile and bending stresses K, = stress limit factor applicable to the Design allowable shear stresses Ken = stress limit factor applicable to the Design allowabee ccrrpressive axial and bending stresses to determine buckling limit NOTES:
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(1) Control of deformation is not insured by these stress I.mit factors. When required by Design Specification, deformation control must be-considered separately.
(2) K., K,, and K e = 1.0 for design of snubbers.
e (3) Stress shall not exceed 0.75.
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(4) 4 shall not exceed 0.42S..
(5) For Service Levels A, D, C, and D, stresses induced on the supports by restraint of free end displacement and anchor motions of piping shall be considered as primary stresses.
- 16) Thermal stresses within the support as defined by f.F.3121.11 need not te evaluated. For Service Levels A and B, primary plus secondar stresses shall be limited to a range of 25, or S, at temperature, whichever is less.
1 NF 3580 DESIGN DY LOAD RATING
. NF 3611 Spacing of Piping Supports Component supports of all types may' be designed Supports for piping with a longitudinal axis in by load rating in accordance with the reouirements of approximately a horizontal position shall be spaced to
(,
NF 3280 for plate and shell type, NF.3380 for linear prevent excessive shear stresses resulting from sag and type, and the applicable Subsubarticle for Standard' bending in the piping, with special consideration given Component Supports.
when components such as pumps and valves impose
.D.
concentrated loads. The suggested rnaximum spans for spacing of weight supports for standard weight and heavier piping are given in Table NF 3611 1.
NF3600 DESIGN RULES FOR PIPING SUPPORTS W83 NF 3610 GENERAL REQUIREMENTS NF 3612 Vibration The design of piping supports shall be in accordance with this Subarticle and the applicable general require-Piping shall be arranged and supported so that
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ments of NF 31to, NF 3210, NF 3310, and NF 3410.
vibration shall be minimized.
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o 1983 Edition NF.3000 - DESIGN Table NF-3623(b).1 sas TABLE NF-3623(b)1
. ELASTIC ANALYSIS STRESS CATEGORIES AND STRESS LIMIT FACTORS 3
FOR CLASS 1,2,3, AND MC LINEAR TYPE SUPPORTS DESIGNED BY ANALYSIS-PIPING SUPPORTS Stress Limit Factors for Leading Categories [ Note (1))
Senice Level Service Level B Senice Level C Senice Level D Test Stress Category Design A
[ Note (2))
[ Note (3))
[ Note (3)]
Loadings Primary Stresses K.
= 1.0
. K,
= 1.0 K.
= 1.33 K.
= 1.5 K.
= 2.0 K.
= 1.33
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(Note (4)]
4 = 1.0
% = 1.0 K.
= 1.33 K,
= 1.5 4
=2.0 K,
= 1.33 (Note ($1)
(Note (S)).
(Note ($))
[ Note (S)]
Kee = 1.3 Ken = 1.0 Ken = 1.33 Ken = 1.5 Ken = 2.0 K.
= 1J3 but stress s but stress es but Stress s but stress s
% of critical
% of critical
% of critical
% of critical buckling stress buckling stress buckling stress buc.kling stress Primary Plus Secon-Evaluation is required for critical buckling for all loading categories. The requirements of this $ubarticle shall be met dary Stresses for this evaluation.
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[ Note (6))
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Peak Stresses Evaluation not required.
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NOMENCLATURE:
K = stress limit factor opphcable to the Design al'owable tensile and bending stresses K, = stress limit factor apphcable to the Design allowable shear stresses Kee = stress I tr t factor apphcable to the Design allowable compressive aulal and bending stresses to determine buckling limit NOTES:
(1) Control of deformation is not insured by these stress limit factors. When required by Design Specification, deformation control rnust be considered separately.
(2) K., K,, and Kee = 1.0 for design of snubbers.
(3) Stress shall not exceed 0.75,.
(4) For Service Levels A,8, C, and D, stresses induced on the supports by restraint of free end displacement and anchor motions of piping shall be considered as primary stresses.
(S) & Shall not exceed 0.423..
(6) Thermal Stresses within the support as defined by NF.3121.11 need not be evaluated. For Service Levels A and B, primary plus secondary stresses shall be limited.ts a range of 23, or 5, at temperature, whichever is less.
a.
r S
4 91
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