chlorinator].
2.12.2.1
In-Stream Float
The in-stream float shall have a range of from 5 to 150 percent of the
average flow through the plant. The measuring system shall include a
float, float rod or stainless steel bead cable, transfer assembly, and cam
mechanism designed to transmit the measurement through mechanical linkage
or through signal transmission of the impulse duration type of the
null-balance inductance-bridge type so as to result in uniformly graduated
units of flow. The float shall be of plastic or stainless steel and the
float arm shall be of stainless steel. The float shall be provided with
stops to prevent overranging and damping, and shall be equipped with a zero
adjustment. All materials of construction shall be of standard
corrosion-resisting materials. Accuracy shall be plus or minus 2 percent
of actual rate over a 5 to one range.
2.12.2.2
Float and Cable
The float and cable shall have a range of from 5 percent to 150 percent of
the average flow through the plant. The crest level shall be measured in a
stilling well. The measuring system shall include a float, cable, drum,
transfer gear assembly and cam mechanism designed to transmit the
measurement through mechanical linkage or through signal transmission of
the impulse duration type of the null-balance inductance-bridge type so as
to result in uniformly graduated units of flow. The float shall be of
polyester, polystyrene, stainless steel or copper, and be of suitable
weight and shape for the intended purpose. The cable shall be
plastic-coated multi-strand stainless steel, stainless steel beads or
multi-strand monel. The drum shall be grooved to prevent overlapping of
the cable. The float and cable shall be provided with stops to prevent
overranging and a zero adjustment. All materials of construction shall be
corrosion-resisting materials. Protection tubes for the cables shall be
provided. Accuracy shall be plus or minus 2 percent of actual rate over a
5 to one range.
2.12.2.3
[Transmitting] Recorder
**************************************************************************
NOTE: On the project drawings, show:
1. Type of plant: (Extended aeration, Step
Aeration, or Complete Mixing).
2.
Design flow.
3.
5-day BOD loading.
4.
Suspended solids loading.
5. Whether a comminutor is needed for plants 1.09
L/s 25,000 GPD or less in size.
6.
Whether mechanical aerator should be allowed.
7. Whether plant should be concrete only, steel
only, or either concrete or steel at Contractor's
option.
SECTION 11375N
Page 64
Previous Page
