WA0101-CS050513TO: Showers, Doug L
Date: 5/13/2005 9:33:16 AM
Subject: Re: Directional bore information ~/~'
Doug,
I had an opportunity to speak with Ken about the proposal to directional drill Denton Creek in lieu of the
conventional bore with steel casing. We are of the opinion that the plans and specifications call for a
pressure rating of 200psi for the pipe, and therefore we will require the DR 9 rather than the proposed DR
11. We will also require that they use the 14" pipe in order to maintain an equivalent ID to that of the PVC.
In addition, the MJ adaptor kit indicates that retainer glands are "available" but sold separately. For
clarification purposes, we should indicate that those will be required as part of the installation.
Feel free to call with any questions or comments.
Keith R. Marvin, P.E.
City of Coppell
(972) 304-7044
kmarvin@ci.coppell.tx.us
>>> "Doug Showers" <DShowers@BHCLLP.COM> 05/12/05 3:00 PM >>>
Good afternoon Keith,
I have attached the information received from Fox regarding replacement
of the cased bore under Denton Creek with a directional bore. I spoke
with Joe at FOx and confirmed that this would be a no cost change.
My concerns are as follows:
1. They have proposed DR-11 HDPE with a max working pressure of 160
psi. Our project requires PVC DR-14 with a working pressure of 200 psi,
I have alerted Joe that the City will likely require DR-9 HDPE (200
psi).
2. The nominal ID of the PVC DR-14 pipe is 11.20 inches. The proposed
12 inch HDPE DR-11 has an ID of 10.3 inches (IPS) or 10.7 inches (DIPS).
The 12 inch DR-9 has an ID of 9.7 (IPS) or 10.1 (DIPS). I am concerned
about the ID and the flow/volume/pressure/head loss associated with the
HDPE vs PVC pipe. Is the City willing to accept a smaller ID pipe in
this area of the project? Our evaluation would be that the head loss
associated with the decreased diameter would be for the most part offset
by the elimination of joints in this 280 foot run of pipe. To be
conservative we could ask the contractor to substitute 14 inch HDPE DR-9
which has an inside diameter of 10.7 inches. This brings us even closer
in size and likely head loss.
Please let me know the City's position on this issue as we prepare a
response to the contractor.
Thank you, Doug
I Keit!~ Marvin 7 Directional bOre information F'~ge !t
From:
To:
Date:
Subject:
"Doug Showers" <DShowers@BHCLLP.COM>
<kmarvin@ci.coppell.tx.us>
5/12/2005 2:57:59 PM
Directional bore information
Good afternoon Keith,
I have attached the information received from Fox regarding replacement
of the cased bore under Denton Creek with a directional bore. I spoke
with Joe at FQx and confirmed that this would be a no cost change.
My concerns are as follows:
1. They have proposed DR-11 HDPE with a max working pressure of 160
psi. Our project requires PVC DR-14 with a working pressure of 200 psi.
I have alerted Joe that the City will likely require DR-9 HDPE (200
psi).
2. The nominal ID of the PVC DR-14 pipe is 11.20 inches. The proposed
12 inch HDPE DR-11 has an ID of 10.3 inches (IPS) or 10.7 inches (DIPS).
The 12 inch DR-9 has an ID of 9.7 (IPS) or 10.1 (DIPS). I am concerned
about the ID and the flow/volume/pressure/head loss associated with the
HDPE vs PVC pipe. Is the City willing to accept a smaller ID pipe in
this area of the project? Our evaluation would be that the head loss
associated with the decreased diameter would be for the most part offset
by the elimination of joints in this 280 foot run of pipe. To be
conservative we could ask the contractor to substitute 14 inch HDPE DR-9
which has an inside diameter of 10.7 inches. This brings us even closer
in size and likely head loss.
Please let me know the City's position on this issue as we prepare a
response to the contractor.
Thank you, Doug
FOX CONTRACTORS, INC.
M~y 13, 200~
FROM:
TO:
SUBJECT:
FOX Contmclor~ Inc.
B1RKHOFF, HENDRICKS & CONWAY, L.L.P.
Attention: DOUGLAS K. SHOWEI~, P.E.
STATE HIGHWAY 12l WATER LINE CITY OF COFIn~L
Proposal to install 280' L.F. of dimctdonal bore in lieu dry, bo~ front aaa. 11+00 to ~aa. 13+80 on
sheet # 5 of plans,
WORK PROPOSAL
280'L.F. diregtiomal bom no stol cal;illg for 12' SDR, 11 water pipe
2g0'L.F. 12" IPS SDR-11 AWWA Performance Pip~ 4100 series (40).
2 - 12" IPS XIP$ SDR-II redu~r.
2 - 12" DIPS SDR-I1 B~ll MJ Ada~ex Kita.
Cotme~ HDPE. TO PVC.
If you have qu~lions, pl~aso e. all meat 972-670-3082, ~.
Thank you,
EO. Box 951 · MIDLOTHIAN, TEXA8 76065 · (g72) 723-6870
EgLO I BE:'b' I ~ zenbse I e~, s.~nI