Azbil KDP Series User manual

OM2-5220-1100
Dierential Pressure Detectors
(Meter Bodies)
Model KDP/KFDB
User's Manual

NOTICE
While the information in this manual is presented in good faith and
believed to be accurate, Azbil Corporation disclaims any implied
warranty of merchantability or fitness for a particular purpose and
makes no express warranty except as may be stated in its written
agreement with and for its customer.
In no event shall Azbil Corporation be liable to anyone for any
indirect, special or consequential damages. This information and
specications in this document are subject to change without notice.
© 2013 - 2020 Azbil Corporation. All Rights Reserved.

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Table of Contents
Chapter 1. DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
1-1. GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1-2. MODELS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1-3. INSTRUCTIONS FOR INSTRUMENTS (TRANSMITTERS AND CONTROLLERS) USED IN
CONJUNCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Chapter 2. STRUCTURES OF METER BODIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
2-1. EXTERNAL VIEWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2-2. STRUCTURES AND OPERATING PRINCIPLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Chapter 3. INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
3-1. GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3-2. BRACKET AND BOLTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3-3. PLACE OF INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3-4. INSTALLATION METHOD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3-5. PRESSURE PIPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
3-6. ELEVATION AND SUPPRESSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Chapter 4. OPERATION METHOD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4-1. DIFFERENTIAL PRESSURE (FLOW) TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
4-2. LIQUID LEVEL TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Chapter 5. INSPECTION AND MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5-1. CHECK FOR LEAK FROM PIPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
5-2. BLOW AND CLEANING OF METER BODY AND PIPING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

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Chapter 1. DESCRIPTION
1-1. GENERAL
The differential pressure detector (meter body) accepts a differential pressure through its high
and low pressure connection ports, converts the differential pressure into a torque force by its
center section to which the high and low pressures are applied through respective diaphragms,
and feeds a torque via its torque tube to a pneumatic transmitter (Model KDP) or a pneumatic
controller (Model KFDB).
Some models of detectors have a flange incorporated with diaphragm for connection of the
high pressure line.
1-2. MODELS
Measured Pressures or Type
of Instrument
Model Numbers of
Instruments Used in
Conjunction
Operator‘s Manual Used
in Conjunction
Standard Type, High/Medium
Differential Pressures
Models KDP11/22
Models KFDB11/22
OM2-5220-1101 (KDP)
OM2-6220-0000 (KFDB)
Standard Type, Low Differential
Pressures
Model KDP33
Model KFDB33
Standard Type, Very Low
Differential Pressures
Model KDP44
Model KFDB44
Flange Type Models KDP61/62
Models KFDB61/62
Remote-sealed diaphragm Type Models KDP71/72
Models KFDB71/72
High Working Pressure Type Models KDP81/82
Models KFDBSl/82
1-3. INSTRUCTIONS FOR INSTRUMENTS ( TRANSMITTERS AND CONTROLLERS )
USED IN CONJUNCTION
For the instructions for instruments used in conjunction, refer to respective Operator‘s
Manuals which cover the operating principles, service and unit replacement procedures, and
calibration and adjustment procedures of these instruments.

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Chapter 2. STRUCTURES OF METER BODIES
2-1. EXTERNAL VIEWS
Although external views of meter bodies differ by models as shown in Fig. 2-1, the bracket
mounting section and instrument connection section are identical for models 11/22, 71/72,
and for models 33/44, 81/82.
Fig. 2-1. External Views of Meter Bodies

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2-2. STRUCTURES AND OPERATING PRINCIPLES
The structures and operating principles of the meter bodies are covered in this section.
2-2-1. Models 11/12, 33, and 81/82
(a) The high and low process pressures (HP and LP) are fed via diaphragms (1) and (2) to
the center section (oil filled section) of the meter body. The HP acts on the differential
pressure detecting bellows from the right hand side (3) and the LP from the left hand side
(4). When in the equilibrium state (zero differential pressure state), identical forces are
exercised on both sides of the differential pressure detecting bellows (5).
(b) As the pressure of the HP side rises thereby increasing the differential pressure, the
differential pressure detecting bellows moves leftward. The movement of the bellows is fed
as a torque via the torque arm to the beam of the transmitter.
1 HP SEAL DIAPHRAGM
2 LP SEAL DIAPHRAGM
3 LIQUID FILL OF HP SIDE
4 LIQUID FILL OF LP SlUE
5 DIFFERENTIAL PRESSURE DETECTING BELLOWS
6 DAMPING CONTROL (OPTIONAL)
7 TORQUE ARM
8 TORQUE TUBE
Fig. 2-2. Operating Principle of Meter Body

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2-2-2. Model 44
(a) The high and low process pressures (HP and LP) are fed via the diaphragms and supports
(1) to the center section (silicone filled section) (2) of the meter body. The HP acts on
the pressure detecting diaphragm from the right hand side and the LP from the left hand
side. When in the equilibrium state (zero differential pressure state), identical forces are
exercised on both sides of the differential pressure detecting diaphragm.
(b) As the pressure of the HP side rises, the support moves leftward. The liquid fill flows
through the damping control (3). The movement of the diaphragm is fed as a torque via
the torque arm (4) to the beam of the transmitter.
1 DIAPHRAGM AND SUPPORT
2 LIQUID FILL
3 DAMPING CONTROL
4 TORQUE ARM
5 TORQUE TUBE
Fig. 2-3. Operating Principle of Meter Body

5
2-2-3. Models 61/62
(a) The high and low process pressures (HP and LP) are fed via diaphragms (2) and (11)
to the center section (silicone filled section) of the meter body. A pressure which is
proportional to the liquid head in the process vessel is fed via the seal diaphragm (2) and
liquid fill to the bellows (5) at the center section of the meter body.
(b) The bellows (5) moves in proportion to the liquid head pressure. The movement of
the bellows is fed as a torque via the plunger (6) and torque arm (7) to the beam of the
transmitter.
1 PROCESS CONNECTION FLANGE
2 SEAL DIAPHRAGM
3 DAMPING CONTROL (OPTIONAL)
4 HP LIQUID FILL (SILICONE)
5 BELLOWS
6 PLUNGER
7 TORQUE ARM
8 TORQUE TUBE
9 OVERLOAD SEAL
10 LP LIQUID FILL (SILICONE)
11 SEAL DIAPHRAGM
12 CENTER BODY
13 LP COVER
Fig. 2-4. Operating Principle of Meter Body

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2-2-4. Models 71/72
(a) The high and low process pressures (HP and LP) are fed via diaphragms (2) to the
center section (silicone filled section) (11) of the meter body. The HP is fed via the seal
diaphragm (2) and liquid fill (4) to the bellows (5) at the center section of the meter body.
The LP is fed bia the seal diaphragm (2) and liquid fill (10) to the bellows (5).
(b) The bellows (5) moves in proportion to the differential pressure between HP and LP.
The movement of the bellows is fed as a torque via the torque rod (8) to the beam of the
transmitter.
1 PROCESS CONNECTION FLANGE
2 SEAL DIAPHRAGM
3 DAMPING CONTROL
4 HP LIQUID FILL (SILICONE)
5 BELLOWS
6 PLUNGER
7 TORQUE ARM
8 TORQUE ROD
9 OVERLOAD SEAL
10 LP LIQUID FILL (SILICONE)
11 CENTER BODY
Fig. 2-5. Operating Principle of Meter Body