Meriam 951 Orifice Plate User Manual
Model 951, Orifice plates concentric-segmental-eccentric, Orifice plates design criteria & tolerances
Meriam Process Technologies
www.meriam.com ph: 800.817.7849 fax: 216.281.0228
Model 951
Orifice Plates
Concentric-Segmental-Eccentric
The most common primary flow element is the concentric orifice plate,
often called the “sharp-edged” orifice plate. Its main advantages are: low
cost, accuracy, ease of installation, variety of construction material and
quick delivery. Much test data has been compiled about orifice plates
and, with the necessary information, an exacting design can be made
providing for excellent metering accuracy.
Engineered for each application, Meriam orifice plates are precision bored
to exact dimensions with a sharp upstream edge to ensure accuracy.
Orifice information is stamped on the unique handle. This handle is
designed to facilitate storage of the plate without damage to the orifice
bore.
Standard Meriam orifice plates are 304 Stainless Steel. Monel, brass, P.V.C.,
316 Stainless Steel and other materials are available. Meriam orifice plate
dimensions meet ISA specifications. Meriam can provide blank orifice
plates for your own boring, too.
Orifice Plates Design Criteria & Tolerances
84
Standards and specifications for orifice plates are listed by the ISA, AGA and
ASME.
All of these do not agree in all ways. Please indicate which specifications you
require so we will provide your orifice plates the way you want them.
Edges – Square and sharp, will not reflect a beam of light when viewed with-
out magnification.
Finish – 15-32 micro-inch roughness
Flatness – Flatness within 0.010 inches, per inch of dam height.
Bore – Orifice bore tolerance in strict accordance with AGA. Gas Measure-
ment Committee Report No. 3, ASME Fluid Meters Committee Report, and
with other societies’ recommendations.
Meriam has furnished many orifice plates for nuclear and fossil fired power
plants, chemical plants, refineries, steel mills and to original equipment
manufacturers for incorporation in their equipment and systems.
Meriam can also provide readout instruments and accessories for complete
flow metering installation.
Line Pipe Size
½”-1½”
2” - 3”
3½”-6”
8”-12” 14”-36”
Orifice Edge
Thickness “e”
1
/
64
”
1
/
32
”
1
/
16
”
1
/
8
”
¼”
Orifice Edge Thickness