CF-Pump Station-CS 870227GINN, INC. CONSUI.TING ENGINEERS
February 27, 1987
Hydro~orage, Inc.
P.O.B.~ 1685
Des Moils, IA 50306
Attn: Mr. Craig Pippett
Re: 1.5 MG Elevated Tank
Inlet/Outlet Pipe
Coppell, Texas
Dear Mr. Pippett:
Reference Mr. Abram DeVaul's letter of February 19, 1987.
Not to belabor this point any further, but to clarify our
previous statements regarding the inlet/outlet pipe and an
accurate depiction of what was proposed, what was constructed
and what information you provided, we offer these comments.
In our opinion, it was not accurate due to the following:
1. No dimensions of lengths of pipe to be restrained were
given.
2. The thrust blocking on the 90 degree bend indicated a
7.5 s.f. bearing area. No "height" (or "thickness") was
shown. According to the Ductile Iron Pipe Association,
the block height should be equal to or less than one-half
of total depth to bottom of block, but not less than the
pipe diameter. This places the "height" between 2 feet
minimum, to 4.5 ft. The block that was poured was
approximately 8' x 8' x 1' in "height." Additionally,
the block height should be such that the block width
varies between one and two times the height. This is not
the case as it now exists.
3. Besides the original four all-thread rods that were
installed between the 45 degree bend and the gate valve,
four additional rods were added between the 45 degree
bend and the exterior concrete ring wall of the tank.
Were you aware of this?
We reviewed the joint restraint calculations that were
provided. Based on the sketchy information provided by
MEGALUG brochure, we are not totally convinced that their
product has been demonstrated to be adequate for the applica-
tion intended.
Mr. Craig Pippett
February 27, 1987
Page 2
Since Mr. DeVaul indicates the combination of the concrete
thrust block and MEGALUG retainer glands provides an adequate
restraint system, then we have no objection to allowing further
construction review on this portion of the project. This letter
shall not be construed as unconditional approval of the
installation.
Sincerely,
Gabe Favre
/ss
cc: Frank Trando'j Randy Fleming
Shohre Daneshmand Butch Ellison
Steve Goram Rueben Martinez
Wayne Ginn