indicating, recording, and integrating type with electric chart drives.
Instrument cases shall be dust-tight metallic or plastic, finished in
manufacturer's standard black, and arranged for flush-panel mounting. Flow
records shall be in thousands of kg pounds per hour on an ink chart
recorder. Steam flow shall be totalized in kg pounds by an integrator
having not less than a six-digit counter. The installation of stainless
steel orifice plates shall include shutoff valves, equalizing valves, and
blowdown valves. Each meter shall have a guaranteed accuracy of plus or
minus 1/2 of 1 percent while operating at 20 to 100 percent of capacity.
Steam-flow orifices and associated steam piping shall be installed in
accordance with the manufacturer's recommendations and labeled with the
following tags:
Tag Number
Service
FR-[_____]
Unit Number 1, Steam Flow
FR-[_____]
Unit Number 2, Steam Flow
FR-[_____]
Unit Number 3, Steam Flow
[FR-[_____]
Export Steam, Steam Flow]
[FR-[_____]
Domestic Steam, Steam Flow]
2.9.12.1
Orifice Plate
The orifice plate shall be sized to produce a 25.42 kPa 100 inch W.G.
pressure differential at the rated flow of the meter as shown on the
drawings. Orifice plates shall be 3.2 mm 1/8 inch thick 316 or 304 SS,
chambered with the sharp edge orifice facing upstream, fitted with a tab
extending beyond flanges showing bore size, differential, and maximum flow.
Calculation of flow shall be made by the manufacturer under ASME MFC-3M,
or equivalent by Spink or American Gas Association. Plates for steam or
condensibles service shall have a weep hole drilled in them when installed
in horizontal meter runs.
2.9.12.2
Flow Transmitters
Pressure differential and transmitting components shall have an accuracy of
plus or minus 1 percent, 0.15 percent repeatability, 4-20 milliamp dc
signal into 0-500 ohms, (if electronic) internal square root extractor,
adjustable zero and span, and equalizing valves. Span range, and working
pressure shall be as shown on the drawings. Transmitters shall be
installed with condensate reservoirs where required to protect transmitter
from excessive temperature.
2.9.13
Boiler Feedwater Flow Meters
**************************************************************************
NOTE: For boilers having less than 4500 kg/hour
(10,000 lb/hour) steaming capacity, a mechanical
feedwater meter may be provided. Plants having
metered zeolite softeners used exclusively for
boiler makeup will not require an additional cold
water makeup water meter. Boilers over 4500 kg/hour
(10,000 lb/hour) capacity will have
indicating-recording meters and they will be
integrating type where indicated.
SECTION 15846A
Page 53
Previous Page
