Dresser Model 10C25 Series K Installation, Operation, and Maintenance Manual
© 2018 Natural Gas Solutions North America, LLC
Page 5 of 74
2.1
Operating Principle
The Dresser meter is designed to measure the volume of gases and gas mixtures with a high degree of
accuracy. The industry accepted rotary type positive displacement operating principle supports
permanent, non-adjustable accuracy by using precision machined two-lobe impellers encased within a
rigid measuring chamber. Measurement accuracy is not affected by changes in gas specific gravity,
pressure, or fluctuating flow.
Figure 1: Two (2) contra-rotating impellers of two-lobe or
‘
figure 8
’
contour
As shown in Figure 1, two (2) contra-rotating impellers of two-lobe or
‘
figure 8
’
design are encased within
a rigid measuring chamber that has inlet and outlet connections on opposite sides. Precision machined
timing gears keep the impellers in the correct relative position. Optimal operating clearances between the
impellers, cylinder, and headplates provide a continuous, non-contacting seal.
This design effectively isolates the gas at the meter inlet from the gas at the outlet. This enables a very
small pressure drop across the impellers to cause them to rotate.
2.2
Performance Characteristics
The 10C25 rotary meter has the following performance characteristics:
•
Manufactured in accordance with the American National Standard specification ANSI/ASC-B109.3 for
rotary type gas displacement meters
•
Not affected by low or varying line pressures
•
Suitable for use at pressures ranging from a few inches of w. c. (water column) to the MAOP of 25 psig
•
Mounts in the gas line like
the Dresser™ Series Z 5C15 and 8C15 meters
2.3
Features
The 10C25 has the following features:
•
Both horizontal (side) and vertical (top) mounting capability
•
Oil-less with permanently lubricated bearings
•
RPM (revolutions per minute) Flow Indicator to indicate flow
•
Differential testing capability
•
Fast prove feature available
•
Compatible with common AMR/AMI devices that require pulse input
•
Compensated and non-compensated versions available
•
IP66 to IP68 rating (depending on pulse output configuration)
•
Multiple connection types, including Sprague #3/#4, 30 LT, 45 LT, and 1-1/2 inch FNPT
For additional specifications, refer to Section 17.
