CF-Village-CS 890330 GINN, INC. CONSULTING ENGINEERS
March 30, 1989
Cajun/Contractors, Inc.
Dallds, Texas 75354-0487
Re: Village Parkway Pump Station
City of Coppell, Texas
Flow Meter Vault
Dear Mr. Hirschey:
Structural review of the modified flow meter vault indicates that the vault
may be subjected to excessive uplift forces during periods of high soil
saturation. Two factors contributing to this possible condition are the
lengthening of the vault to accommodate your flow tube and your use of wall
sleeves, thus eliminating restraint on the vault from the piping. We
understand from our conversation with Mr. Durbin that wall rings will be used
in place of the wall sleeves; however, to provide an additional margin of
safety against uplift, we request that the following modifications be made to
the flow meter vault:
1) Increase the depth of the gravel underneath the flow meter vault to 6"
from 3".
2) Install two (2) pressure relief valves in the vault floor slab to relieve
hydrostatic pressure in the backfill. The valves should be 4" diameter
by 8' length, Clow F-1492 or equal. The valves should be placed along
the centerline of the pipe at 1/3 intervals (+5'-1" from each wall)
inside the flow meter vault.
Please prepare an itemized breakdown of any additional costs involved in the
installation of the relief valves. Additionally, please see that the above
modifications are incorporated into the preparation for placement of the flow
meter vault floor slab.
Please contact us if you have any questions or need additional information.
Sincerely,
Sanfortt W. Case, P.E.
Project Manager
attachment
cc: Russell Doyle, P.E Steve Goram
Start Reed, P.E., Reedcon, Inc. H. Wayne Ginn, P.E.
Gabe Favre J.R. Richardson
Smoky Ginn File 380
Ned Durbin, Cajun Contractors, Inc.
17103 Preston Road · Suite 100 · LB 118 · Dallas, Texas 75248 · Phone 214/248-4900
CAST IRON PRESSURE RELIEF VALVES
--~ F-1492 FLOOR TYPE
'~ 4' Diameter only
.' Must be installed in Vertical Position
.
"i! Body Lengths
· .; ~inimum is 6 inches
,;. ~axlmum is 2~ inches
~'~ S~ify I~glh when o~ering ~ ~ ~..~ v; ~.J V
; F-1492 line illustration J.J ~
Flor Type are "fixed" dimensions
· '. Pressure Relief Valve Seclional View
-: ~r~,,r, relief valves nrc tot pi~ci,~ i, Lh, Tim Oiow Pre~ure Relio[ VGlve~
bottom of concrete tanks to keel) empty tanks construc~d that neither the cover or strainer
--' from floating when there is an excess of ground- can becmne separa~d from the body
wa~r un4erneath and aroimd them. When valve, due to ground-water pressure around
with this condition exist, the outside wa~r pres- the tank. llowever, when necessary, both may
I'hey . sure will raise the cover of the valve ~nd allow be e~ily removed by turning t.lmm
fem. the wa~r ~ enler the tank I~ equalize prc~ left t.o free lhem from l.he locki,g lugs cast on
can .." aures inside ami Dutside of tank and, thus, inside of hodv. l~ad is punted, peened, and
ired. preveut, thc t,lulk from floating, machined int;~ grooves on undershle of cover
igth, and top of body, forming a non-corroding lead
{e ~ 'l'h. wdw~.q cai, be furnished in any I..ly Io h,:ul conlllct wh(.n
loor- h. nglh frnm (i ind.,a thru 24 in.he, in incre- The cover weighs tl,l~TOximnlelv
&oy iil¢,nl.a -f one inch. SLsndard body h~nglhs are st.arts Io open
listed ~d)ove. of watcr. '
~PI~L INSlAL~TION
HYDROSTATIC RELIEF VALVE
SAND TAMPED CRUSHED STONE
~4 ~ PLACE BELOW SCREEN
~ JmpoflanJ ~ote
1 ~ In order for the F-1492 floor-ty~ valve Lo o~raLe
I ~ correctly, it must be ins~lled in a vertical position.
12
10
161
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