ML20206A322
| ML20206A322 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Sequoyah |
| Issue date: | 07/31/1986 |
| From: | Brackett C, Missimer J TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML082410757 | List: |
| References | |
| WR28-1-85-122, WR28-1-85-128-DRFT, NUDOCS 8704070487 | |
| Download: ML20206A322 (20) | |
Text
.. -_. _ -..
n,
,n w.,_
1 * '.'
943
'87 0126 004
~
p.,..
?
QAtb:wd Tennessee valley Authority f-Office of Natural Researces and Econente Development Divisten of Air and Water Researces l
Engineering Laboratory N
(.
87020750280 BUSSLE MIGRATION IN SDISING LINES SLOPED AT SMALL ANSLES
}'W i
l
)
J Ltc aNc.i r..:ren
.+.1 ')7 '8 7 i
y...
l Report No. WR28-1-05-122
- i.,5, m, 't 1
,.u
.. s e s..
iun i
i j
',,,u.,-
,o u i
ev A y,. 3
,..,g y,.". ' d > :.. ywI
..,,,c,-.,,,,-
. m..,
i we -
- o. a n,
i',.
i j
-) - - l - '
- Q Prepared by Jack R. Missiner. Ph.D., P.E.
en.
C. Ann Brackett l
Research and Test Section i
Norris. Tennessee 407pj[$$00 7
July 1986 P
1078P 1/.!(,/u7 - Wsnittsc
}
cer nt'ts. st 26 c-r
.,ew-
.,mww - r w w rw w e.-w w e
-r-m o m,wwm m-
- '='~n**"'W'""*
- ;3..;;
.,... w l
a.
$.s. *
- 2 l
Ts IMIKEIR I
t.agg, l
Introducties" I
Descriptise of Tests g
S-Test Results Discussion of Results-Conclusions,
i References I
i LIST OF FIGURES i
1.
Test Setup 2.
Sent Pipe Cohfiguration
~
i 3.
Subble Migration in 1/2-Inch Schedule 160 55 Pipe Withest Coupling 4.
Subble Migration in 1/2-Inch Schedule 80 55 Pipe
}
Withest Comp 11ng 5.
Subble Migration in 1/2-Inch Schedule 160 $$ Pipe With Coupling 6.
Subble Migration in 1/2-Inch Schedule 80 55 Pipe l
With Compling i
l l
- LIST OF TABLES I
1.
Setpoints for Tests 2.
Summary of Sata for 3/8-Inch $$ Tubing 3.
Subble Migration in Schedule 1601/2-Inch Pressurized Lines 4
Sebble Migration in Schedule 801/2-Inch Pressurized Lines 5.
Subble Migration in tent Pipes t
)
l i
1018P I.
1
..s.
l'l,
_4..
OW f\\l0 g(
?.
b y
I
,,, C'..'
.g
\\
I
..l*
J
/
t -,;.s
/
,".Q<
,./
l l
'} i,h r
.. ;c l
f*.'
l 1
Vs J..
a.
-z..
_s j
f d
W c_-
j - ' ',',
u O.
_ g L- '.., -
_ ' '.. Q w'.
-t p,
.s \\
r
.8...
..g
., s wpr- &.a ' *.nW, O,,% a. *,,; % -
- n..,
a-n
.s.
- de
'z
,f gg 'X, l '. *,' ','.' '
i
, ' M+,1,
()
w or z h y g. cyy,rq' p.g,.y,g.
e.;f,.
..a :s y
,p h
,p, i O.,t. '
,)[:k' f
"' ]
,/ :-
E 1-
~..
&&W &=k./\\qN.
. 4$). -u v Asl.,
.[
.....e;-
u c
'~
h
'. mesi.
'.r.?,I!.1.Qdid,
/ L Q l
l
,. l,,?
s Ih.s t $[iW,ji l
)
INTRODUCTION The TVA Engineering Laboratory has conducted several studies (1, 4,
- 5) documenting the potential for air entrapment in liquid-filled sensing lines.
The sizes and configurations of the sensing lines investigated wre chosen to simulate actual installations at Watts Bar Nuclear Plant used for both flowrate and liquid level measurement.
The present industry standards (2, 3) recommend that sensin,g lines be installed with a minimum slope of one-inch per foot.
The recommended absolute minimum slope is 1/8-inch per foot..As part of the Engineering Laboratory's investigation, it was requested to examine the characteristics of air bubble migration in pipes sloped at less than 1/8-inch per foot. Three pipe sizes'were tested at five different slopes for four differgnt bubble sizes.,
DESCRIPTION OF TESTS The test setup is shown in Figure 1.
Two steel beams are clamped together to make a sturdy, level support, one end of which can be raised
- up and down by means of a tripod.
Pipes were clamped to the beam and the hydrophones mounted as shown in Figure 1.
The hydrophones were used to document bubble migration. Water was supplied to the system from a water hose attached to the lower end of the pipe.
Bubbles were inserted by means of a syringe through a valve as shown in Figure 1.
Equipment to be tested included 1/2-inch schedule 80 stainless steel pipe, 1/2-inch schedule 160 stainless steel pipe, and 3/8-inch stainless steel tubing.
Tests were to be run on each type pipe as a st-aight section, as a straight section with a coupling inserted in the
. e, and as a section bent to the configuration shown in Figure 2.
Each of these setups was to be tested at atmospheric pressure and also at 100 psig. Table 1 presents a summary of the setpoints for the tests.
1078P
J.
e e-
\\
%*/
%og 0" ?A. Cot 'stv0.
w.
' N.
'OT as n.
is rT.
io rr.
Figure 5: B' nt Pipe Configumtion e
\\
l 1
~
w.
t I
i t
s t
j j
[
3 o
l l
-l
.t l
I u
4 u
- r..
l l
q i
v l
l w
I fJ Gi' g,
l I
e y/
JD l
Da si q y I
Slopoa
/ I a
1/4 Inch / foot l
4 el l
6 1/9 Inch / foot 1 -d b
c I/IS inch / foot -
d 1/32 Inch / foot.-
o 1/64 Inch / foot A
A A
a a
A a
a a
A a
A I
I a
a a
a a
a a
a e
a a
4' s
Rverage Velocity (In/sec)
Figure 3.
Bubble Higration i n 1/2-Inch Schedule 160 SS Pipe Hithout Coup 1tng
e 4
TEST RESULTS Test results confirm that for pipe slopes of less than one inch per feet bubble migration velocities decrease as pipe slope decreases or as bubble size decreases.
This is in agreement with findings from previous studies (4, 5).
Graphs of the average bubble velocity for the schedule 80 and schedule 160 pipes without the coupling can be seen in f
Figures 3 and 4.
For the schedule 80 pipe the ses11er bubbles; were determined to be moving at less than 0.1 inch per second-and were not plotted.
Figures 5 and 6 are graphs of bubble velocity for schedule 80 and 160 pipes with a coupling.
All bubble site and slope continations were tested, but those that caused.the bubble to hang in the coupling were not plotted.
Hydrophones were placed on either side of the coupling to determine if the bubble became* trapped in the coupling.
Tests were attempted on the 3/8-inch tubing, but no meaningful bubble velocities were obtained.
At the largest slope (1/4 inch per foot) several bubble stres were put into the pipe and forced past the first hydrophone, but none of them reached the secondr hydrophone in the alloted time.
This meant that the bubble was moving slower than 0.1 inch per second, if it was moving at all.
At times there was evidenes that i
the bubble completely stopped.
This was seen by the constant wavering of the hydrophone signal when the bubble became hung in the vicinity of the hydrophone.
Since bubbles were not migrating at the largest slope, no further tests were conducted on the 3/8-inch stainless steel tubing.
A summary of the data obtained is shown in Table 2.
For the pressurized tests a nitrogen bottle was connected to the high end of the pipe.
After the bubble was introduced into the line, the line was pressurized to 100 psig.
For these tests the size of the actual air bubble introduced into the line was such that, after being pressurized, the bubble would be the required volume.
Results show that pressurization of the line has no ef feet on the migration velocity of the air bubbles.
Testing of the pressurized lines was discontinued after enough data was gained to justif y the previous statement.
Tables 3 and 4
)
are a sunraary of the acquired data.
' 107ep
.~
v l
~
I i
i 8
j s
i i
a o
a 9
5 s
y.
s l
I I
U 4
O l
l v
l t
l l
u W
/
J 3
j m
j e
/
l
.o d
l D t
~
m
/
Slopos 3
4 a
1/4 inch / foot l
l
.......6 1/9 inch / foot l
l
/
h-
e 1/16 Inch / foot -
d 1/32 inch / foot 4
~
e I/64 Inch / foot ;
1 i
i I
a a
a a
eI 9
a a
a a
R a
a a
a a
a a
a n
a a
a g
e i
a 3
4 s
i Rverage. Velocity (in/sec) i
).--
Figure 4.
Bubble HIgratIon in 1/2-Inch Schedule 80 1
i
3--
.c,.gf.
n 1
I
~
8 8-,-
t l
[
s
-l t e V..
, Ne
~
0
.h 4
u v
t
?. i-e n
3 in k.:
=*
i D
)
~
I hy
\\
.O
.D a lE 3
L to Slopes i
a 1/4 Inch / foot l
.........b 1/8 inch / foot 3
- ---- e I/IS Inch / foot -
-d 1/32 inch / foot
.- e 1/64 inch / foot e
g n
e n,
e a
a 4
s i
Rverage Velocity (In/sec)
Figure 5.
Bubble Migration in 1/2-Inch Schedule 160 SS Pipe Hith Coupilng
b
-['-
' ' V.y 76(A g 1i L
.i I
e l
a e
4Y s
1 (u.
,1 n
- .s g
0 4
g,,.
.l u
e j
j N
e I
- 3 b,
4
~
i e
i m
j ja m
gg,,,
a a
1/4 inch / foot b
t/8 Inch / foot i
i
--a 1/16 Inch / foot -
8 t
i
[
-d 1/32 Inch / foot
-o 1/84 Inoh/ foot l
t l
g i
2 3
it 5
l Rverage Velocity (In/sec) i l
Figure 6.
Bubble Nigration in 1/2-Inch Schedule 89' je SS Pipe Hith Coupilng l
I
5 Tests on the schedule 160 bent pipe show no significant change in bubble velocity from velocities in the straight pipe.
Results can be seen in Table 5.
Also shown in Table 5 are results.of the tests on the schedule 50 bent pipe.
Bubbles in this pipe tend to become trapped in the bond.
i OfSCUS$10W OF RESULTS According to physical model tests bubbles as small as one cubic centimeter.will migrate at slopes as low as 1/64 inch per foot in the schedule 160 straight pipe without the coupling.
In the schedule 80 i :-
pipe, however, the smaller bubbles tested, at slopes less than 1/16 inch iL per foot, become trapped, or at leas't move at speeds less than 0.1 inches i
per second.
In pipes with the soupling, only the larger bubbles tested at the larger slopes tested will pass through.
For those bubbles that do go through the coupling, there is a small decrease in velocity.
As stated previously pressurization of the lines to 100 psig f
apparently has no noticeable effect upon the velocity of the bubbles.
There is one discrepancy in the schedule 80 pipe with the 1-and 2-cubic i!
centimeter bubbles at a slope of 1/4-inch per foot.
This can be
[
attributed to the large variance obtained in the unpressurized data (see
{
Figure 4).
If lines were under greater pressure, bubbles would be I
expected to move slower since their density would be greater.
i l
The bubbles slowed down slightly, but did pass through the bent portion of the schedule 160 pipe.
In. the schedule 80 pipe the 5 cubic centimeter bubble was th'e only one that would pass through the bent portion, and it migrated' considerably slower than the s'ame size bubble in a straight section of schedule 80 pipe.
Y CONCLUSIONS Results from this set of tests indicate that none of the pipes tested are satisfactory for use as sensing lines at slopes of less than j
1/4-inch per foot.
This is consistent with previous results (4. 5).
i j
1078P i
h:
y-
_N j.
6
-g.
?l str m acts I
1.
Missiner, J.
R.,
' Air Velds la Liquid-Filled Seastag Lines.* TVA p
Report No. WR28-1-85-110. May 1984.
2.
International Standard Organization.
- Fluid Flow in Closed Conduits -
Connections for Pressere Signal Transatssions Between Primary and te-Secondary Elements " ISO Standard 2186, 1973.
3.
ASME, Fluid Meters Their Theory and Ano11 cation. Sixth Edition,1971.
4.
Wojnovich, Mark 5.,
Missiner, Jack R.,
and C. Ann Brackett, "Subble Migration in inclined Sonstag Lines," TVA Report No. WR28-2-88-107, 3
August 1985.
5.
Missiner, Jack R.
and C.
Ann Brackett,
- 5 easing Line Air Bobble Migration Tests for Watts Bar Nuclear Plant," TVA Report No.
W28-1-85-121. June 1986.
e 4018P s
f,*
7 setpoints for Tests Pipe Pipe Settle Diameter Pipe Slope Sise Wat&7 Pressure Coupling Transition Level 1
U 5ht11 M, U B410.
feet M M g ytg g glg 1/2 80 1/4 5
x x
x x
3 x
x x
x 2
x x
x x
1 x
x
-x x
1/8 5
x x
x x
3 x
x x
x 2
x x
x x
1 x
x x
x 1/16 5
x x
x x
3 x
x x
x 2
x x
x x
7 x
x x
x 1/32 5
'x x
x x
3 x
x x
x 2
x x
x 1
x x
x x
x 1/64 5
x x
x 3
x x
x x
2 x
x x
x 1
x x
x x
x 1/2 160 1/4*.
5 x
x x
3 x
x x
x 2
x x
x x
1 x
x x
x x
1/8 5
x x
x 3
x x
.x x
2 x
x x
x 1
x x
x x
x 1/16 5
x x
x i
3 x
x x
x 2
x x
x x
1 x
x x
x x
i l
1078P h'
.7,-wwmC-"'FP*N'*
gi.
%..=..
y3v..
,g.s -
y M
- w i
['
(contiased)
Setpoints for Tests
[
Pipe Pipe Sabble Level P'
Biameter Pipe Slope Size Meter Pressere Compling Transition
.j.
M B]! tith M
icen m M g gig g glg, 1/32 5
x x
x x
3 x
x J
x 2
x x
x x
1 x
x x
x
{
1/64 5
x x
x x
3 x
x x
x 2
x x
x x
1 x
x x
x 3/8 Tubipg 1/4 5
x x
x 3
x x
x 2
x x
x 1
x x
x 1/2 80 1/4 5
x x
x 3
x x
x 2
x x
x 1.
x x
x 1/8 5
x x
x 3
x x'
x 2
x x
x 1
x x
x 1/16 5
x x
x 3
x x
x 2
x x
x 1
x x
x 1/2 160 1/4 5
x x
x 3
x x
x 2
x x
x 1
x e
x x
1/8 5
x x
x 3
x x
x 2
x x
x 1
x x
x 10787 1
- i. :
i
,o g
]
3 I
(coattamed)
I
}
Setestats for Tests b
Pipe Pipe Bubble Level l
i Diameter Pipe
- Slope Size Mater Pressure Coupling Transition
+4 (inches) M
- UBlfil, fec) g,ggig 100. nsie ML, y/,,a wL. M/.g 1/2 80
'O 5
x x
x 3
x x-x 2
x x
x 1
x x
x 1/2 160 0
5 x
x x
3 x
x x
2 x
x x
1 x
x x
1
- 9 j
i l
I i
/
s 1078P 1
I
t 4:
- 1g
=
f-IAEL.1
+. -
Summary of Data for 3/8-Inch $$ Tubing Subble Stre Pipe Slope Average Velocity fin /ft) fin /see) fee) j 2
1/4 less than 0,1
~
3 1/4 less than 0.1 1
1/4 less than 0.1 r
5 1/4 less than 0.1 1/2 1/4 less than 0.1 1/4 1/4' less than 0.1 O
n 9
e e
e m
i 1078P 1
i
i 11 DELL.1 Subble N1gratten in Schedule 160 1/2-Inch Pressurized Lines Slope Sabble Size fin /ft) fee)
Average Velocity fin /seel 1/4 5
1.86 3
1.53 2
1.41 1
1.23 1/8 5
1 14 3
0.97 2
0.95 1
0.73 L'16
~
i 0.60 3
0.58 2'
O.52 S
9 4
4
. r-l 1078P,.
~
I
,_,y-,
- -. - - - - - - - - - - - - - - - ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
fyp -
.p......
m.
1g
=
y..
TM gir f
Sabble Migratten la Schedste 801/2-Inch 10 Pressortaed Lines Slope Suthis Stre Average Velocity pa;&-
Lin/_fli iett iin/seel 1.
r#'
1/4 5
2.98 3
2.45 2
2.40 '
1 2.20 r
1/8 5
2.02 3
1.69 2
1.27 1
1.06 O
9 4
l e
O 9
1 4
O 1078P
p '..
p: '......
s....
13 e-Subtle Migration is Best Pipes Aversee Velaetty I'.:-
Subble Size Sefore tone After Send 2
S.
M iec) fin /see) fin /see) 1 1
Schedule 160.1/2* + -
5 2.53 2.30 3
1.79 1.72 2
1.65 1.58 1
1.35 1.29 Schedule 80,1/2* +
5 4.00 2.74 3
2.55 stuck in bend 2
2.23 stuck in bend 1
1.45 stuck in bend l
1 1
- '1078P i
1 i
ENCLOSURE 2 SEQUOYAH NUOLEAR PLANT INSTRUMENT SENSING LINE SLOPE QUESTIONS INSTRUMENT MAINTENANCE INSTRUCTION IMI-118 e
4 J
r 4
i
)
i i
1 J
1
-i t
i e
-_v.-
m_,,-.