Meriam 70H, 72H User Manual

ACCUTUBE

File No. 957:440-11

INSTALLATION

INSTRUCTIONS

10920 Madison Avenue · Cleveland, Ohio 44102 · [phone] · FAX [phone]

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ACCUTUBE INSTALLATION INSTRUCTIONS

CONTENTS PAGE

ACCUTUBE MODEL NO. CONFIGURATOR................................................................3

ACCUTUBE MODELS .....................................................................................................4

1 SYSTEM CONSIDERATIONS.........................................................................................5

2 OPERATIONAL CONSIDERATIONS............................................................................. 9

3 READOUT INSTRUMENTATION .................................................................................. 9

4 INSTALLATION PROCEDURE ......................................................................................9

4.1 GENERAL REQUIREMENTS.................................................................................9

4.2 SERIES 10A, 11A, & 12A ......................................................................................10

4.3 SERIES 20T, 21T, 22L, 23L, 40H, 41H, 42H & 43H.............................................11

4.4 SERIES 24D & 25D ................................................................................................ 12

4.5 SERIES 33T INSTALLATION ..............................................................................13

4.6 PROBE REMOVAL................................................................................................15

4.7 SERIES 37L, 70H & 72H INSTALLATION..........................................................15

4.7.1 EQUIPMENT REQUIRED ..........................................................................15

4.7.2 INSTALLATION – ½” AND 1” DIA. PROBES W / SOCKET DRIVE.....15

4.7.3 INSTALLATION – ½” AND 1” DIA. PROBES W / GEAR DRIVE .........17

4.7.4 INSTALLATION – 2 3/8” DIA. PROBES W / SOCKET DRIVE.............. 18

4.7.5 INSTALLATION – 2 3/8” DIA. PROBES W / GEAR DRIVE...................20

4.7.6 SPECIAL DOUBLE-SUPPORT INSTRUCTIONS.....................................21

4.7.7 RECTRACTION PROCEDURE FOR SOCKET DRIVE UNITS...............22

4.7.8 RECTRACTION PROCEDURE FOR GEAR DRIVE UNITS ...................23

4.8 DIRECT TRANSMITTER MOUNT HEADS WITH EQUALIZING VALVES...24
AND INTEGRAL RTD OPTION, SERIES 40H – 43H, 70H & 72H

4.9 SPECIAL APPLICATIONS (DUCTS/SADDLE CLAMPS/ROTATED HEAD)..25

5 OPERATIONS .................................................................................................................26

6 INTERCHANGEABILITY..............................................................................................27

7 MAINTENANCE & REPLACEMENT PARTS .............................................................28

8 TROUBLESHOOTING ...................................................................................................28

9 CALCULATIONS & FLOW COEFFICIENTS......................................................... 29-31

ACCUTUBE MODEL NUMBER CONFIGURATOR

2

SERIES LINE SIZE PROBE PROBE INSTRU. INSERT. MOUNTING WET TAP
DIA. MATL. VALVES VALVE DRIVE
(1) THE FIRST THREE DIGITS

IDENTIFY THE STYLE OF PROBE

10A = SCH 40 INLINE
11A = SCH 80 INLINE
20T = LOW PRESSURE INSERTION, SINGLE MOUNT
21T = LOW PRESSURE INSERTION, DOUBLE MOUNT
22L = HIGH PRESSURE INSERTION, SINGLE MOUNT
23L = HIGH PRESSURE INSERTION, DOUBLE MOUNT
24D = HIGH PRESSURE FLANGE, SINGLE MOUNT
25D = HIGH PRESSURE FLANGE, DOUBLE MOUNT
33T = LOW PRESSURE WET TAP
37L = HIGH PRESSURE WET TAP
40H = DIRECT XMITER MOUNT W / 3-VALVE, SINGLE MT
41H = DIRECT XMITER MOUNT W / 3-VALVE, DOUBLE MT
42H = DIRECT XMITER MT W / 3-VALVE & RTD, SINGLE
43H = DIRECT XMITER MT W / 3-VALVE & RTD, DOUBLE
70H = DIRECT XMITER MT W / 3-VALVE, WET TAP
72H = DIRECT XMITER MT W / 3-VALVE & RTD, WET TAP

(2) NOMINAL LINE SIZE

0005 = 1/2” LINE 0100 = 10” LINE
0007 = 3/4” LINE 0300 = 30” LINE
0060 = 6” LINE 1020 = 102” LINE
0080 = 8” LINE 1440 = 144” LINE

(2A) PROBE DIAMETER

A = 1/2” D = 3/8”
B = 1” E = 3/4”
C = 2-3/8” F = ALL INLINE SERIES 10A & 11A

(3) SENSOR MATERIAL

00 = 316SS PROBE WITH BRASS CONNECTION HEAD (SERIES 20T, 21T & 33T ONLY)
02 = CARBON STEEL (SERIES 10A & 11A ONLY)
03 = ALL 316SS PROBE (AVAILABLE IN ALL SERIES)
10 = BRASS BODY AND PROBE (SERIES 10A & 11A ONLY)
30 = PVC WITH THREADED PROCESS CONNECTIONS (SERIES 11A ONLY)
31 = PVC WITH PLAIN END PROCESS CONNECTIONS (SERIES 11A ONLY)
SP = SPECIAL - CONSULT FACTORY

(4) INSTRUMENT SHUTOFF VALVES, TYPE & MATERIAL

XX = NONE
00 = BRASS (SERIES 10A, 20T, 21T & 33T); = BRONZE (SERIES 22L, 23L, 24D & 37L)
02 = CARBON STEEL
03 = 316 SS (ALL SERIES EXCEPT 40H-43H, 70H & 72H. CALLS OUT HEAD MAT’L FOR THESE)
04 = C.S. OS&Y TYPE (SERIES 22L, 23L, 24D, 25D & 37L ONLY)
05 = 316 SS OS&Y TYPE (SERIES 22L, 23L, 24D, 25D & 37L ONLY)
14 = PVC BALL VALVE (PVC 11A ONLY)
SP = SPECIAL - CONSULT FACTORY

(5) INSERTION VALVE, TYPE & MATERIAL

XX = NONE REQUIRED
00= BRONZE BALL VALVE (33T ONLY)
02 = CARBON STEEL BALL VALVE (37L, 70H & 72H ONLY)
03 = 316 SS BALL VALVE (33T, 37L, 70H & 72H ONLY)
04 = C.S. OS&Y VALVE (37L ONLY)
05 = 316 SS OS&Y VALVE (37L ONLY)
SP = SPECIAL - CONSULT FACTORY

(6) MOUNTING, TYPE & MATERIAL

XX = NONE REQUIRED
01 = STEEL SADDLE CLAMP (20T, 22L & 33T ONLY)
02 = 3000# C.S. THRED-O-LET WITH BRASS PACKING (20T, 21T & 33T ONLY)
03 = 3000# C.S. THRED-O-LET WITH 316 SS PACKING (20T, 21T, 22L, 23L, 33T, 37L, 40H, 41H, 42H, 43H, 70H & 72H)
04 = 316 SS THRED-O-LET WITH 316 SS PACKING (20T, 21T, 22L, 23L) NYLON PKG (33T) GRAFOIL PKG (37L, 70H & 72H)
06 = ROUND DUCT MOUNT HARDWARE, C.S. (20T, 21T, 22L, 23L ONLY)
07 = RECTANGULAR DUCT MOUNT HARDWARE, C.S. (20T, 21T, 22L, 23L ONLY)
08 = PVC THRED-O-LET (20T, 21T, 22L, 23L, 33T ONLY)
1C = 150# C.S. FLANGE (24D & 25D, SPECIAL 37L, 70H & 72H)
3C = 300# C.S. FLANGE (24D & 25D, SPECIAL 37L, 70H & 72H)
6C = 600# C.S. FLANGE (24D & 25D, SPECIAL 37L, 70H & 72H)
9C = 900# C.S. FLANGE (24D & 25D, SPECIAL 37L, 70H & 72H)
1S = 150# S.S. FLANGE (24D & 25D, SPECIAL 37L, 70H & 72H)
3S = 300# S.S. FLANGE (24D & 25D, SPECIAL 37L, 70H & 72H)
6S = 600# S.S. FLANGE (24D & 25D, SPECIAL 37L, 70H & 72H)
9S = 900# S.S. FLANGE (24D & 25D, SPECIAL 37L, 70H & 72H)
SP = SPECIAL - CONSULT FACTORY

(7) DRIVE MECHANISM FOR WET TAPS

SC = SOCKET DRIVE
GD = GEAR DRIVE

ACCUTUBE MODELS

3

10A and 11A 20T and 21T

22L and 23L

40H thru 43H

24D and 25D 33T 37L Socket Drive

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1 SYSTEM CONSIDERATIONS

1.1 Selection of the proper location and position of the Accutube flow sensor within the
piping system is important. The first consideration is to locate the Accutube with proper
upstream and downstream straight pipe runs. This is required to assure a fully developed
symmetrical flow profile at the Accutube. Accuracy can be affected if sufficient piping
is not provided. Table 1 shows recommended straight run requirements with various
types of upstream flow disturbances. For inline series sensors the straight pipe run must
be of the same schedule/I.D. as the Accutube.

RECOMMENDED STRAIGHT RUNS OF PIPE

(Upstream Length in Terms of Internal Diameter of Pipe - See Notes)

UPSTREAM
FLOW
DISTURBANCE
ONE ELBOW

WITH

STRAIGHTENING

VANES

6 - 8 8 - 10

OR TEE
TWO 90° BENDS IN

8 - 10 12 - 15
SAME PLANE
TWO 90° BENDS

10 - 12 24 - 28
DIFF. PLANE
REDUCERS OR

8 - 10 8 - 10 8 - 10
EXPANDERS
ALL VALVES

10 - 12 24 - 28 24 - 28

(SEE NOTE 3)

TABLE 1

WITHOUT

STRAIGHTENING

VANES-IN-PLANE

WITHOUT

STRAIGHTENING

VANES-OUT-PLANE

Note 1: Downstream straight run of pipe should be a minimum of 4 to 5 internal diameters.

Note 2: The values listed in Table 1 are acceptable for most applications. Additional lengths are

recommended where precise measurements are desired.

Note 3: Recommendations for valve disturbances are for non-throttling (fully open) position

only. The Accutube should not be located downstream of a throttling valve.

Note 4: Straightening vanes (where used) shall be installed 2 diameters downstream of the

upstream flow disturbance.

Note 5: Deviations from the above recommendations will normally not affect repeatability of the

flow signal.

Note 6: Combination of various types of fittings can cause severe flow distortion, the results of

which are unpredictable. Installations with fitting combinations other than those listed
above should be approached with caution. Flow straightening vanes are strongly
recommended to insure accurate flow measurement.

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1.2 Determine the position of the Accutube and indicating instrument with respect to the
pipe. Selection of the entry location (i.e. in from top or bottom, etc.) is determined by
considering the fluid in the pipe. Sections 1.2.1 through 1.2.4 give general requirements
for Accutube position and installation, and specific recommendations for each general
category of fluid (1.2.1-Liquid; 1.2.2-Gas; 1.2.3-Steam; 1.2.4-General Requirement).

1.2.1 LIQUID FLOW METERING

1.2.1.1 With liquid flow the readout instrument is normally located below the
Accutube. This prevents air entrapment in the instrument lines.
Figures 1.1 through 1.4 show recommended orientation for liquid flow.

1.2.1.2 See Section 1.2.4 General Interconnection Requirements.

1.2.1.3 Instrument lines should be properly sloped (1/2” per foot) without
high points that may cause air entrapment. If this is not possible, air
vent valves must be placed at any high points in piping. Trapped air is
a frequent cause for measurement error with liquids. Refer to Figs. 1.1
thru 1.4.

1.2.1.4 The air vent valves should be bled on a regular basis during normal
operation and upon restart after a system shutdown.

1.2.2 GAS FLOW METERING

1.2.2.1 Few restrictions apply to system arrangement in dry gas flow. Figures

1.1, 1.2 and 1.5 are recommended for simplicity in installation.

1.2.2.2 For installations where condensation or entrained liquids accumulate in
the instrument piping, it is recommended that the instrument be
mounted above the Accutube or install the Accutube in the top portion
of the line. If mounting the instrument below the Accutube is
necessary, then sediment traps and/or drain valves should be used as in
Figure 1.6.

1.2.2.3 See Section 1.2.4 for General Interconnection Requirements.

1.2.3 STEAM FLOW APPLICATIONS

1.2.3.1 As in liquid flow, the indicator should be located below the Accutube.
Figure 1.1 shows the recommended configuration. This configuration
allows condensate to collect in instrument lines and finds its natural
level within the Accutube. See Figure 1.4 for top entry (probe) in
horizontal lines.

1.2.3.2 An installation in a vertical pipe should only be performed when a
horizontal line location is not available. This installation should be as
in Figure 1.2. A special “rotated head” Accutube is normally used.
This permits side port connection, allowing installation similar to
Figure 1.2.

1.2.3.3 See Section 1.2.4 for General Interconnection Requirements.

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The indicator must be placed far enough away from the Accutube to prevent thermal damage from line
heat. Allow 1 ft. of uninsulated instrument piping for every 100° F of process temperature.

1.2.3.4 Slope the instrument lines to probe at an incline of approximately 1/2”
per foot to prevent air entrapment.

WARNING: DO NOT ATTEMPT TO FILL INSTRUMENT LINES
IF SYSTEM CONNECTING LINES ARE UNDER PRESSURE.

1.2.3.5 Fill the instrument lines with water before connecting the Accutube or
opening block valves.

1.2.3.6 Allow approximately 1/2 hour after system startup for condensate level
to stabilize. Stabilization time may be reduced by section 1.2.3.5
above.

1.2.3.7 Accutubes should not be used for steam applications when the
differential pressure is less than 10” water column.

1.2.4 GENERAL INTERCONNECTION REQUIREMENTS

1.2.4.1 Instrument lines to the Accutube shall be as large as possible in liquid
and steam applications. For Accutube with 1/2” NPT connections,
1/2” pipe or tubing is recommended. Accutubes with 1/8” NPT
connections should use 1/4” pipe or tubing.

1.2.4.2 Use of the optional instrument shutoff valves at the Accutube head are
recommended.

1.2.4.3 Use of a 3-valve manifold is recommended at the indicator to aid
system startup and to ease indicator maintenance and calibration.

1.2.4.4 Where instrument-piping slopes are required, use 1/2” per foot
minimum.

1.2.4.5 The length of the instrument lines does not affect accuracy. Long lines
can, however, dampen the indicator response time.

1.2.4.6 Test the system for leaks after connecting instrumentation to assure that
no leaks exist.

1.2.4.7 In situations where accumulation of sediment or condensation within
the piping is possible, a system drain or pressure blow down should be
performed on a regular basis. Valves are recommended for
indicators/transmitters without drain valves/plug.

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2 OPERATIONAL CONSIDERATIONS

2.1 The Accutube flow sensor is a bi-directional flow meter. It can measure flow in either
direction. The Accutube head is labeled High and Low pressure as observed for normal
flow directions. With reverse flow, the High-pressure signal will occur at the Low­pressure port and vice versa. Reverse flow measurement is as precise as forward flow.
This unique feature allows measurement of flow that changes direction. Special
consideration should be given to the indicating instrument. Instruments which allow
positive and negative (zero center) differential pressure readings are best applied here.

2.2 Accutube probes have limits as to the maximum flow rate that can be tolerated without
risking damage to the sensor. The limits are defined as the maximum allowable
differential pressure. See the Accutube general catalog which lists the maximum
allowable differential pressures for your Accutube model.

2.3 Installation of the Accutube in locations where significant pipe vibrations exist should be
avoided. Double mount style Accutubes are recommended where vibration is a concern.

3 READOUT INSTRUMENTATION

3.1 Many types of readout instrumentation can be used to measure the Accutube differential
pressure. The most common types are manometers, dial gauge indicators, electronic
transmitters/transducers or electronic gauges. Each type has its own installation and
operational characteristics. Refer to manufacturer’s manuals for installation instructions.

3.2 Mounting position can affect zero indication on certain types of instruments. In such
cases, the zero setting should be adjusted after installation of the instrument.

3.3 When a mercury manometer is used with a steam or liquid flow a correction factor must
be applied to the flow calculations. Refer to Handbook, File No. 957:081, for
determining the correction factor.

4 INSTALLATION PROCEDURE

4.1 GENERAL REQUIREMENTS

4.1.1 Prepare the surface of the pipe or duct where the Accutube is to be mounted.

Proper preparation involves removal of scale, rust, paint and grease for proper
welding of the threaded coupling.

4.1.2 Drill or burn a hole through the pipe at the mounting location. The hole should

be 1/16" to 1/8" larger than the probe diameter as identified in Table 4.

TABLE 4

PROBE

DIAMETER

RECOMMENDED

DRILL SIZE
3/8 7/16
1/2 9/16
3/4 13/16

11-1/16

2-3/8 2-1/2

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4.1.3 Double support type sensors require a second hole on the opposite side of the
pipe. Location of this hole is important as it establishes proper alignment of the
probe with respect to the flow. A common method of locating the opposite
support hole is by wrapping a piece of string totally around the pipe, with the
string crossing square to the pipe. The position can be marked at 1/2 the total
length of the string.

4.1.4 Center the threaded weld coupling over the hole and tack weld in place.

4.1.5 Thread the packing gland fitting in place (compression type), and insert the
probe into the pipe. Observe the position of the probe assuring that it is
perpendicular within the tolerance shown in Figure 4.1. If adjustments are
required, remove the probe and packing, and thread a pipe into the threaded
fitting a few feet long. With the leverage of the pipe force the threaded fitting
into the proper position.

DO NOT TRY TO USE THE ACCUTUBE AS A LEVER. DAMAGE TO THE
PROBE AND/OR PACKING CAN RESULT!

4.1.6 Once alignment is verified, perform a final weld of the threaded fitting.

4.1.7 Re-assemble the packing and insert the Accutube as described in Section 4.3.

FIGURE 4.1 ACCUTUBE PROBE POSITIONING

(Maximum Allowable Misalignment)

4.2 INLINE FLOW SENSORS: SERIES 10A, 11A & 12A

4.2.1 The inline series flow sensors are flow-through devices in which the line must
be interrupted for the device to be installed.

4.2.2 Positioning of the sensor is the same as recommended for the other types of
sensors as listed in Section 1.0.

4.2.3 Connections to the main line are made through either threaded pipe fittings,
solvent cement for PVC plain end type, hose connections for plain end types, or
soldered joint for copper tube units.

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