Issue/Rev. 0.6 (12/18) ║ MN01005 • Page 5
2-Bladed Double Case PD Meters Service Manual
Introduction
1 – Overview
This manual provides detailed inspection and service information for the models of Smith Meter
®
Double Case, 2-bladed Rotary Meters listed. See the Related Publications section for Specifica
-
tion, Part Lists, and Installation/Operation information pertaining to your specific model of meter.
Double case meter construction features ease of main
-
tenance and service. For example, the measuring unit
can be removed vertically from the outer housing with
little spillage and without disturbing pipe connections.
Also, within a given size, complete metering units
and parts are interchangeable. As a result, the simple
removal and disassembly steps encourage periodic
preventive maintenance inspections.
It is suggested that a detailed record be maintained for
each meter in the installation. Nameplate data (Figure
1), clearances, progressive totalizer readings, meter
factor, parts used, and other similar information pro
-
vide background material for scheduling a preventive
maintenance program. An increase in meter factor
drift against throughput can be used as the basis for
making an inspection.
The time of the first inspection must be based on the
operating conditions imposed by the installation.
Flow rate, lubrication properties of the fluid, and the possibility of abrasive contaminants are points
to consider. Then, at the time of inspection, the condition of the meter should indicate whether
the inspection interval can be lengthened or shortened.
When ordering parts or inquiring about a unit, be sure to include complete model and serial
number information from the plate, Figure 1.
Note:
Meters constructed to special specifications (designated by 6-digit serial number) may have
clearances in variance to those shown in this manual. Consult your representative or the factory
for the correct information pertaining to your meter.
1.1. Description
Smith Meter
®
double case rotary meters
are of the positive displacement type, Fig
-
ure 2. The metering mechanism is an in
-
ner unit bolted into the outer housing. The
double case design eliminates distortion
of the measuring chamber due to pres
-
sure differential and piping strains. Pipe
connections are confined to the outer
housing, which means the meter can be
removed by taking off the cover assembly
and lifting it out. Inspection, maintenance,
and service are greatly simplified through
the double case design.
The measuring function is accomplished
in a chamber of precise volume created
by the moving blades, rotor, body, and
cover. There is a smooth flow of product
through the meter. The blades rotate
around a fixed cam, which causes them
to move out to, but not touch, the body of
the meter. Four chambers per revolution
are formed as the rotor and blades are
turned by product flow.
Figure 1
Figure 2 –
Horizontal Double Case Meter
Universal Nameplate for PD Meters
Artwork # 554608701 Rev 1
ECN 80009698
FMC Measurement Solutions Inc.
Erie, PA 16510
MODEL
SERIAL NO.
ASSEM. NO.
MAWP
W&M
FLOW
RANGE
METER CLEARANCES SIZED FOR:
TEMP.
MAX.
VISC.
MAX.
