PROGNOST®-NT
Safety Protection and Online Condition Monitoring
for Rotating Equipment
Automated Diagnoses
and Messaging
Scalability
Performance
Optimization
Operating Condition Recognition
and Threshold Adjustment
Contents
Introduction ..................................................................................................................................................................................... 4
Proven by experience ..................................................................................................................................................................... 5
PROGNOST®-NT system overview and capabilities ....................................................................................... 6
Asset Performance Management ................................................................................................................................................. 6
PROGNOST®-NT ............................................................................................................................................................................... 6
PROGNOST®-NT modules profiles ................................................................................................................................................. 7
System scalability ............................................................................................................................................................................ 8
Diagnostic capabilities ................................................................................................................................................................... 9
PROGNOST®-SILver ....................................................................................................................................................................... 10
Machine Condition Visualization (VISU) .................................................................................................................................... 11
Safety Analyses .............................................................................................................................................................................. 12
Early Failure Detection ................................................................................................................................................................. 13
Wear Monitoring ............................................................................................................................................................................ 14
Performance Optimization .......................................................................................................................................................... 14
Lubrication Monitoring ................................................................................................................................................................ 14
Process Data Analyses .................................................................................................................................................................. 15
Component Tracking .................................................................................................................................................................... 15
Tech Corner – Advanced technologies .................................................................................................................. 16
Why vibration monitoring? ......................................................................................................................................................... 16
Automated p-V diagnoses ........................................................................................................................................................... 17
Monitoring of compressor components .............................................................................................................. 18
Piston rod and Plunger ................................................................................................................................................................. 19
Crosshead ........................................................................................................................................................................................ 20
Cylinder and Packing lubrication ............................................................................................................................................... 20
Crankshaft bearings ...................................................................................................................................................................... 20
Crankshaft ....................................................................................................................................................................................... 20
Process problems ........................................................................................................................................................................... 21
Discharge and Suction valves ...................................................................................................................................................... 21
Rider rings and Piston sealing rings ........................................................................................................................................... 21
Packing ............................................................................................................................................................................................ 22
Cylinder liner and Compression chamber ................................................................................................................................ 22
Monitoring of centrifugal equipment ...................................................................................................................
System scalability ..........................................................................................................................................................................
Data acquisition and SIL 2-certified safety protection ...........................................................................................................
Signal Plausibility Check ..............................................................................................................................................................
Ringbuffer .......................................................................................................................................................................................
23
24
24
24
24
Sensor positions ................................................................................................................................................................... 25
Sensor types and uses .................................................................................................................................................................. 25
Sensor signals and positions ....................................................................................................................................................... 25
Signal analyses and display .......................................................................................................................................... 26
Conclusion ...................................................................................................................................................................................... 26
3
Introduction
PROGNOST Systems started monitoring reciprocating
compressors more than 25 years ago. The first commercial
installation was realized in 1990. Today, PROGNOST®-NT is
monitoring all kinds of rotating machines all over the world.
Over the years, PROGNOST Systems has developed an excessive customer orientation that is reflected in our continuous
dialog with our customers and their influence in our R&D
process. Our Customer Support repeatedly gets very good
4
marks for compentence, responsiveness and supportiveness
within our annually conducted Customer Satisfaction Survey
according to our ISO 9001 certification.
We will continue to strengthen our market position and
maintain our brand to be the No. 1 supplier for Asset Performance Management systems for all rotating equipment.
Proven by experience
A reliable, full-featured monitoring system requires a solid
number of installations and many years of field experience.
No amount of “laboratory” testing can reflect the conditions of the actual operating environment – much less the
characteristics of many different operating environments
over extended periods of time. What assurance do you have
that your monitoring system will perform as promised? How
much confidence do you have in the accuracy of the diagnoses your system generates?
mine the amount of time in which the vendor has resolved
problems and implemented user suggestions from the field
in order to refine the performance of their monitoring system. Ask for references. Contact as many of them as possible.
Better still, visit user sites whose environments most closely
match your own. Input from vendor representatives is useful.
However, uncensored comments from genuine users are
invaluable in deciding whether a prospective system will
meet your expectations.
Insist that your vendor documents the amount of time their
system has been in actual use in operating locations. Deter-
Just ask us: We look forward to bring you in contact with the
PROGNOST User community.
5
PROGNOST®- NT
System overview and capabilities
Asset Performance Management
PROGNOST®-NT
A full Asset Performance Management system owns a total
approach in terms of machine condition monitoring with
emphasis on safety protection and early failure detection.
Precise detection of irregularity is accomplished by capturing a complex combination of signals and analyzing them in
a way that allows even minor changes to be recognized. By
detecting slight changes and understanding their consequences, early failures are detected – and false alarms
are avoided. This type of in-depth intelligence demands a
monitoring system that has been perfected through 25 years
of field experience.
PROGNOST®-NT is an automated machinery diagnostic
system incorporating safety protection and online condition monitoring. It is developed specifically for reciprocating
machinery but is also used for different kinds of rotating
equipment. It detects impending failures at an early stage
and assigns the affected components. Operation-critical
damages are avoided and maintenance measures can be
performed efficiently.
Additional features like permanent monitoring of wear
parts, such as piston rider rings or the integration of DCS
values, e.g. temperatures, help to maximize machinery uptime and minimize maintenance efforts.
6
PROGNOST®-NT modules profiles
Data Acquisition & Safety Protection
PROGNOST®-SILver – SIL 2-certified protection hardware
Safety Analyses
Lubrication Monitoring
Process Data Analyses
Component Tracking
Transient data recording for alarms or user events and visualization
of online signals and trends
Monitoring of critical components, automatic pattern recognition
Trend based monitoring of wear parts
Automated p-V diagram analyses for optimizing compressor efficiency
and detection of leakages
Continuous monitoring of cylinder and packing lubrication
DCS data analyses and trending, visualization with P&I diagram
Maintenance planning tool, component lifetime registry
Visualization
Signal visualization, machine status, online and trend data, logbook
Early Failure Detection
Wear Monitoring
Performance Optimization
7
System scalability
As your needs change and your experience with this system
grows, it is likely that you wish to extend coverage to other
machines.
Think Big – Start Small
PROGNOST®-NT is scalable in two ways: First, it is functionally scalable, allowing new or additional capabilities such
as measuring loops or diagnostic modules to be added
to an installed system without inordinate cost or difficulty.
Second, PROGNOST®-NT is scalable in magnitude. In other
words, this system offers the expansion of monitoring to
additional machines. This allows a simple, cost-sensitive
pathway for growth.
Turn key PROGNOST®-NT system – completely assembled,
configured, tested and ready for shipping
8
Diagnostic capabilities
PROGNOST®-NT does not solely indicate problems but also
provides an accurate diagnosis with specific component
identification, location and indication of the extent of damage. Equipped with this information, you can make wellfounded decisions about the maintenance procedures you
need to take and the time you need to take them.
PROGNOST®-NT Swift for temporary and periodical monitoring
applications, e.g. initial machine start-up or after compressor
overhauls or regular short-term measurements, e.g. every 3 month.
9
PROGNOST®-SILver, 19” hardware for various installation options,
e.g. cabinet frame mounting, wall mounting, housings
PROGNOST®-SILver
Data acquisition and SIL 2-certified safety protection
The vital role of a protection system to reduce the risk of
serious damages is covered by PROGNOST®-SILver. This
hardware has proven its effectiveness and reliability on a
daily basis, worldwide and in different process environments. PROGNOST®-SILver is the only machinery protection
system for reciprocating machinery with a SIL 2 certificate
(IEC 61508:2010) for all shutdown loops connected (max. 68
loops). The intelligent combination of vibration, dynamic rod
position, dynamic cylinder pressure and temperatures analyses provides the most reliable shutdown parameters in the
industry. The PROGNOST Systems invention of “Segmented
Vibration Analysis” and a unique algorithm ensure fast, reliable machine shutdown and no false alarms.
Signal Plausibility Check –
Avoiding alarms caused by instrumental
PROGNOST® uses specialized signal processing to avoid false
alarms caused by electrical or hardware failures such as broken or loose wires, short circuits or broken terminals. Even
out-of-range signals are identified and indicated as “UNSAFE“.
Users are informed about any “UNSAFE” loop immediately.
PROGNOST®-SILver gives you a stand-alone safety protection system but also convenient wiring options for the data
acquisition of PROGNOST®-NT.
PROGNOST®-SILver in Ex-housing for field installation (Ex-zone)
optional without cooling
10
Vibration signal segmentation
Machine Condition Visualization (VISU)
Signal visualization: machine status, online and trend
data, logbook
PROGNOST®-NT Visualization is much more than a “data
display” software. It allows active access to all kinds of signals,
analyses and logbook entries. User-friendly design of functions, views and data access enables even untrained users
to receive status information of the machine with just a few
clicks. All of our customers enjoy the logical and easy way
to investigate waterfall diagrams, alarm logbooks and trend
views. Supported with audio replay functions for vibration
measurement and easy data export to standard Office software, you find the most comprehensive tool set for diagnosis.
Machine status view in the “OneClick Cockpit”
Logbook with all alarms, machine starts and stops
3D trend p-V diagram with automated efficiency analysis
11
60
m il
TDC
BDC
TDC
45
30
15
0
0
15
30
45
60
75
90
10 5
12 0
13 5
15 0
16 5
18 0
19 5
21 0
22 5
24 0
25 5
27 0
28 5
30 0
31 5
33 0
34 5
36 0
degree crank angle
R D S tage 1, P eak-P eak over 8 S eg. .. 45 d egrees
m il
40
30
20
10
0
1
0
15
2
30
45
60
3
75
90
10 5
4
12 0
13 5
15 0
5
16 5
18 0
19 5
6
21 0
22 5
24 0
7
25 5
27 0
28 5
8
30 0
31 5
33 0
34 5
36 0
degree crank angle
Peak-to-Peak analysis of the piston rod position (operational run out)
Safety Analyses
Visualizes the Safety Protection analyses performed
by PROGNOST®-SILver, e.g. online signals, trends and
safety limit violations.
Reliable safety protection hardware is only one side of the
story. Answers as to “why” a safety incident occured is the
next step further. PROGNOST®-NT Safety Analyses is a module to visualize and save online and trend data to provide all
information required for precise root cause analysis.
Ringbuffer
Transient data recording allows to replay all monitored
signals as time waveform during a safety shutdown, alert, or
machine start-up by examining a gapless recording in an
uncompressed format – revolution by revolution. The ringbuffer offers this possibility of subsequent analyses; the time
frame of seven minutes before and three minutes after the
ALERT, SHUTDOWN or UNSAFE alarm can be closely evaluated using all recorded time signals from all dynamic sensors
and process values in the PROGNOST®-NT system.
12
Monitoring the following components
(Legend: see page 19 and following)
4,0
g
TDC
BDC
TDC
3,0
2,0
1,0
0
-1,0
-2,0
-3,0
-4,0
0
15
30
45
60
75
90
105
120
135
150
165
180
° CA
195
210
225
240
255
270
285
300
315
330
345
360
CHS 1, RMS values via 36 Seg. .. 10 degrees
5,5
g
5,0
4,5
4,0
3,5
3,0
2,5
2,0
1,5
1,0
0,5
0
1
0
2
15
3
4
30
5
45
6
7
60
8
75
9
10
90
11
105
12
13
120
14
135
15
16
150
17
165
18
19
180
° CA
20
195
21
22
210
23
225
24
25
240
26
255
27
28
270
29
285
30
31
300
32
315
33
34
330
35
345
36
360
Online vibration signal and segmented analysis for one crank revolution
Early Failure Detection
• Avoidance of costly damages through identification of
mechanical defects at an early stage
• Information instead of data: clear text messages with
local and functional clarity
With its dedicated analyses PROGNOST®-NT detects developing damages at an early stage, providing users with
valuable lead time for proactive machine operation management and efficient maintenance planning.
Automatic detection of operating conditions
PROGNOST®-NT recognizes changing machine operating
conditions and automatically switches to corresponding,
pre-defined threshold sets to avoid false warnings caused by
changing load conditions.
Pattern recognition with fully integrated
diagnostic database
All PROGNOST®-NT users benefit from experiences of more
than 4.25 million recip operating hours annually and more
than 25 years of diagnostic experience. All major failure
modes are integrated within a failure pattern database
and can be diagnosed automatically providing clear text
messages including failure type and location of the failing
component. The diagnostic capabilities are a blend of the
most reliable and useful soft computing disciplines – from
Fuzzy Logic to Rule Based.
Monitoring the following components
Automated threshold setting
Using the automated threshold setting, the system can easily
be configured for new operating conditions to guarantee
high quality of warnings.
13
Wear Monitoring
• Quantified and exact display of wear development
• Accurate planning of maintenance activities is
supported and eased
PROGNOST®-NT Wear Monitoring provides wear trend plots
of critical components. Thus development from normal wear
to threatening damage becomes recognizable. The operator
is advised by threshold violations and therefore wear-based
damages become predictable and avoidable. As a result, the
number of machine stops decreases as well as the number
of replaced components because components can be operated over their full wear potential.
• Analyses of the compression cycle
• Piston rod load
• Piston rod load reversal
These data analyses provides operators and maintenance
personnel with all information that is required for an optimized operation of reciprocating machinery.
See also page 17.
Monitoring the following components
Machine outages to perform periodic manual inspections
can be avoided when an accurate means to quantify remaining rider band potential is continuously available.
Reliable and meaningful piston rod position
PROGNOST®-NT uses the full revolution of the piston rod
position signal to provide a precise piston rider ring wear
calculation. The dynamic rod position signal is also used to
monitor the mechanical condition of the piston rod and its
connections. Used as a protection parameter for automatic
shutdown, it is the only method to detect cracked piston
rods before they fail.
Monitoring the following components
Lubrication Monitoring
• Continuous measurement of lubricant volume,
based on flow rate
• Long-term and short-term trend analysis of individual
measuring points
• Passive measuring sensors, usable in hazardous areas
With this application, any number of lubrication lines can
be equipped with PROGNOST®-NT Lubrication Monitoring
sensors to monitor the flow rate. These sensors are ideally located near the injector to get information about lubrication
quantities. The flow rate of the individual lubrication points
is monitored by trend analysis and changes become visible
at an early stage. Blockages or leakages are identified before
they cause component failures.
Performance Optimization
• Improving operative efficiency and reducing
energy consumption
• p-V diagram analysis for performance and
condition monitoring
Measuring dynamic cylinder pressures, PROGNOST®-NT
evaluates the efficiency and condition of a compressor and
its sealing elements. The continuous and automated p-V diagram analyses detects impending valve failures most reliably.
Apart from p-V diagram analyses, the following additional key
values are calculated, monitored and recorded in the logbook:
14
Monitoring the following components
Component history: installation date and operating hours
Process Data Analyses
Component Tracking
• Communication through use of standard interfaces
for data exchange
• Display and threshold monitoring of defined
DCS values as trends
• Definition of operating conditions with
DCS parameters avoiding false warnings
• Demand-based planning and tracking
of all maintenance activities
• Logging of component real-time running hours
for a comparison of spare part lifetimes
This module establishes a direct communication between
DCS and PROGNOST®-NT. When operating conditions of
the compressor are changing, e.g. speed or pressure, these
changes are reflected within the PROGNOST®-NT analyses to
avoid false warnings. Conversely, status messages from Safety
Protection or Early Failure Detection modules are forwarded
to the control room personnel for further actions. Information
exchange is realized with standard interfaces Modbus RTU,
OPC or Profibus. The module also offers the possibility of displaying DCS data as graphic trends and continuously comparing these trends with warning threshold values.
This module supports predictive maintenance strategies
with an efficient tool for planning and tracking maintenance activities along with real-time component lifetime
information. Users receive all information required: running
time of individual components (based on actual machine
run-time, not on installation date) and a timeline, displaying
all planned and realized maintenance activities. Furthermore, expected dates for replacement of wear parts can be
configured.
Monitoring the following components
15
Tech Corner
Advanced technologies
20
g
TDC
BDC
TDC
10
0
-10
-20
0
15
30
45
60
75
90
10 5
12 0
13 5
15 0
16 5
18 0
19 5
21 0
22 5
24 0
25 5
27 0
28 5
30 0
31 5
33 0
34 5
36 0
degree crank angle
15
g
crosshead guide Cyl.1 , R M S valu es via 36 S eg. .. 10 d egrees
10
5
0
1
0
2
15
3
4
30
5
45
6
7
60
8
75
9
10
90
11
10 5
12
13
12 0
14
13 5
15
16
15 0
17
18
16 5
19
18 0
20
19 5
21
22
21 0
23
22 5
24
25
24 0
26
25 5
27
28
27 0
29
28 5
30
31
30 0
32
31 5
33
34
33 0
35
34 5
36
36 0
degree crank angle
Crosshead vibration signal and segmented analysis
Why vibration monitoring?
The most important and well established technique for
machine monitoring is vibration analyses. However, not all
vibration analyses are the same. Seemingly minor differences in data acquisition and evaluation strategies have
dramatic impact on the quality of signal diagnoses. Choosing the proper mathematical evaluation method is the key
to reliable Early Failure Detection and Safety Protection. Reciprocating machinery has specific vibration characteristics,
e.g. vibration peaks during valve opening and closing, which
must be taken into consideration to avoid false alarms.
Segmentation
Monitoring systems should continuously acquire and
diagnose machine vibrations for each revolution and then
segment signals into crank angle-related portions. This allows harmless but sometimes erratic machine behavior to
be rightly identified as a “good condition” – thereby avoiding
false alarms.
16
PROGNOST Systems invented the “Segmented Vibration
Analysis“ and thus determined that it is the best approach
to subdivide the 360° of one revolution into 36 segments of
10° crank angle each. This is the most accurate proportion of
an average impact width related to one revolution. Vibration
signals must be evaluated using the most accurate mathematical analysis. For reciprocating machinery, only RMS (Root
Mean Square) analysis has proven reliable. RMS analysis is
superior because it considers not only amplitude but also
the energy content of an impact.
Pressure curve with piston rod load
Automated p-V diagnoses
The benefits of optimal equipment performance are clear:
reduced energy consumption and increased productivity.
Tracking performance can also provide other benefits, such
as early warning of impending gas leakages. Unfortunately,
losses in efficiency often go undetected by many monitoring systems that focus on vibration, piston position and temperature only. Machine efficiency – like other key parameters
– should be monitored continuously.
PROGNOST®-NT checks machine efficiency and provides
comprehensive analyses that identify how to restore optimum operation. Analyses begin by detecting any changes
in dynamic pressure during operation and performing
automated, specialized p-V analyses to identify components
causing efficiency reductions. They also incorporate influences resulting from today’s compressor regulations. Finally,
they analyze other key values such as compression cycle,
piston rod load and piston rod reversal. Monitoring systems
should compile all this information to give a comprehensive
view of machine efficiency.
17
Monitoring of compressor components
Valve Failures
29%
Piston Rod
7%
Misc
7%
Sensor Failure
6%
Crosshead
5%
Flow control caused problems
4%
Piston Rings
3%
Plunger
3%
Rider Rings
3%
Piston
2%
Bearing
2%
Leackage
2%
Liquid slug
2%
Process
2%
Pulsations
2%
Packing
1%
Cylinder
1%
5%
18
10%
15%
20%
Piston rod and Plunger
As for double-acting compressors, alternating tensile and
compressive forces on the piston rod are the result of gas
compression on the crank end side (CE) or head end side
(HE) of the compression chamber. These forces from two opposing directions act alternately upon the piston rod.
Loosened connections
The integrity of motion works is ensured via vibration analyses and rod position monitoring. Accelerations on the crosshead slide gaplessly record vibration arising as the result of
increasing clearances. Subsequent diagnosis identifies actual
deviations in the vibration pattern.
Piston rod position analyses reveal connections that are in
the process of detaching at an early stage, e.g. cracks. By
permanent rod position measurement even weakened connections (e.g. low contact pressure between piston nut and
piston) are detectable.
Overload/excessive piston rod load
(compressive and tensile forces)
The compressive and tensile forces affecting the piston
rod can be calculated continuously.
Plunger monitoring (Hyper compressor)
For Hyper compressors, orbit monitoring (horizontal/vertical
displacement of the plunger, “plunger run-out”) is recommended to detect excessive wear of the packing. Increased
vibration is detected at an early stage to prevent damaging
of the brittle hard metal plunger. An automatic shutdown is
crucial to avoid costly consequential damages. Additionally,
gap protection can also be used for safety shutdown.
PROGNOST®-NT monitoring modules recommended
• Safety Protection
• Safety Analyses
• Early Failure Detection
• Wear Monitoring
• Performance Optimization
19
Crosshead
Segmented vibration analysis (see page 16) allows the early
detection of mechanical damages within motion works,
from the connecting rod to the piston. Loosened connections, e.g. between connecting rod and crosshead, are
detectable at an early stage as they create characteristic
vibration peaks at rod load reversal points.
Wrist pin
Wrist pin failures are usually consequential damages caused
by loss of lubrication. Using p-V monitoring, dynamic rod
load changes periods can be calculated. If these periods are
too short, a loss of lubrication of the wrist pin is creating a
critical situation.
PROGNOST®-NT monitoring modules recommended
• Safety Protection
• Safety Analyses
• Early Failure Detection
• Wear Monitoring
Cylinder and Packing lubrication
20
Crankshaft bearings
Vibration analysis assists in the early detection of mechanical damages within motion works, e.g. the connecting rod.
Due to the low operating speed of most piston compressors,
temperature monitoring of bearings is not always distinct.
The friction heat, generated by a damaged bearing, often
is insufficient to produce a significant rise in temperature.
In contrast, vibration allows sleeve bearing damages to be
recognized immediately. Unlike temperature instrumentation, vibration measurement can be installed even if no
borehole at the bearing cap is designed for the sensor by
the manufacturer.
PROGNOST®-NT monitoring modules recommended
• Safety Protection
• Safety Analyses
• Early Failure Detection
Crankshaft
Measurement of lubrication flow quantities takes place
through special flow transmitters. Clogged lines and leakages often are not recognized by the customary method of
line pressure monitoring because backflow is distributed
evenly in the remaining oil channels. Flow quantity sensors,
installed at each lube oil line, precisely record lubrication
quantity and trigger an alarm in case of excessive or insufficient lubrication. As a result, lubrication undergoes complete
measurements, making the reading of sight glasses obsolete
and thus reducing the time spent by maintenance personnel in hazardous areas at the machine.
During compressor operation, the crankshaft is exposed
to continuous torsional vibration. When the machine was
designed, a definite vibration behaviour was calculated and
the shaft was sized correspondingly. However, the use of
load controls such as stepless valve unloaders generates
operating conditions which may not have been taken into
consideration during the design phase. As a consequence,
resonances can be excited which result in unplanned
loads for the crankshaft and its drive connection. To enable
damage-free operation despite changing flowrates, continuous monitoring of torsional vibration is recommended.
PROGNOST®-NT monitoring modules recommended
• Lubrication Monitoring
PROGNOST®-NT monitoring modules recommended
• Early Failure Detection
Process problems
Rider rings and Piston
sealing rings
Liquids in the compression chamber cause a short term rise
of the piston. It can be detected with a peak-to-peak analysis
of piston rod position using a displacement sensor. Another
way to detect liquid carryover is provided by a crosshead
slide acceleration sensor when incompressible liquid is
pressed through discharge valves. This often results in high
vibration around TDC and BDC.
Automated p-V diagram analysis is one of the most important methods for evaluating the condition of piston sealing
rings. For the detection of leaking piston sealing rings on
a double acting cylinder, the two opposite compression
chambers are analyzed in parallel. If changes appear in both
compression chambers, it can be considered as an indication of leaking piston sealing rings.
Both analyses are highly recommended as shutdown signals
to prevent severe consequential damages such as piston rod
failures or broken cylinder head.
The vertical position of a piston is an important indicator for
wear of piston rider rings. The measured vertical position of
a piston rod can be converted into a lowering in the piston
centre, which corresponds to the wear of the rider rings. To
receive accurate rider ring wear values, only the segmented
monitoring of each complete revolution gives reliable
results.
PROGNOST®-NT monitoring modules recommended
• Safety Protection
• Safety Analyses
PROGNOST®-NT monitoring modules recommended
• Performance Optimization
• Wear Monitoring
Discharge and Suction valves
Automated p-V diagram analysis (pressure/volume diagram)
is one of the most important methods to determine the
condition of valves. Valve leakages cause characteristic
changes in the measured pressure curve which can be
recognized with p-V analyses. The dynamic pressure curve
measured is converted to a p-V diagram for which particular characteristic values are calculated. These values, e.g.
discharge losses, polytropic exponents or the crank angle of
the suction valve opening, are assigned warning thresholds
which result in warning messages when exceeded.
Acquisition and analysis of the vibration on cylinders assists
the early detection of mechanical damages, e.g. cracks in the
valve body or valve plates. Flow noise of damaged valves as
well as shifted valve opening or closing events are detectable through high resolution measurement with acceleration sensors.
Measurement of valve temperature is the traditional method
here. Using a temperature sensor, gas temperature in the
valve chamber is measured. If the temperature at a valve
is clearly increased, a damage, e.g. leak, can be assumed.
However, if there are several valves on the cylinder, costs
have to be taken into consideration as a temperature sensor
is required for each valve.
PROGNOST®-NT monitoring modules recommended
• Early Failure Detection
• Performance Optimization
• Process Data Analyses
21
Packing
22
Cylinder liner and
Compression chamber
Automated p-V diagram analysis: Increased leakages cause
characteristic changes in the indicated pressure curve. Appropriate analyses are capable to differentiate between valve,
piston ring and packing leakage. The results are compared
with the pattern recognition database and displayed as clear
text.
The cylinder liner can be damaged by worn-out rider rings
and solid residue in the compression chamber, e.g. caused
by gas impurities. These types of damages are detected
with a peak-to-peak evaluation of piston rod position using
a displacement sensor as well as crosshead vibration. Both
analyses are recommended as shutdown signals.
PROGNOST®-NT monitoring modules recommended
• Performance Optimization
• Process Data Analyses
PROGNOST®-NT monitoring modules recommended
• Safety Protection
• Safety Analyses
• Wear Monitoring
• Performance Optimization
Monitoring of centrifugal equipment
System scalability
Signal Plausibility Check
PROGNOST®-NT is scalable in two ways: Functional scalability, allowing new or additional capabilities such as diagnostic modules to be added to an installed system without
inordinate cost or difficulty. Scope scalability, in other
words, this system offers the expansion of monitoring to
additional machines.
PROGNOST® uses specialized signal processing to avoid false
alarms caused by electrical or hardware failures. Even out-ofrange signals are identified and indicated as “UNSAFE”. Users
are informed about any “UNSAFE” loop immediately.
Data acquisition and
SIL 2-certified safety protection
Transient data recording allows users to replay a safety
shutdown, alert, or machine start-up by examining a gapless
recording of all signals in an uncompressed format – even
revolution by revolution. The ringbuffer offers the possibility
of subsequent root cause analyses; the time frame of seven
minutes before and three minutes after the ALERT, SHUTDOWN or UNSAFE alarm can be closely evaluated using all
recorded time signals from all dynamic sensors and process
values in the PROGNOST®-NT system.
The vital role of a protection system to mitigate the risk of
serious damages is covered by PROGNOST®-SILver. This hardware has proven its effectiveness and reliability on a daily basis, worldwide and in many different process environments.
PROGNOST®-SILver holds a SIL 2 certificate (IEC61506:2010)
for all shutdown loops connected (max. 68 loops) by design.
24
Ringbuffer
Sensor positions
Bearing vibration
Axial shaft position
Speed Bearing temperature
Radial shaft position
Radial shaft position
Sensor types and uses
Sensor signals and positions
Accelerometer
This commonly used sensor, has a high frequency range and
can be easily integrated into Velocity values. The sensor can
be mounted for x, y and z-axis measurements and should be
mounted as close to energy source as possible (i.e. bearing
cap, gear etc.). The accelerometer probe is used to detect
bearing defects (sleeve and rolling element), gear defects,
electrical anomalies, belt defects etc..
Signal
Position
Displacement
Radial shaft position
Axial shaft position
Shaft
Bearing
Shaft end
Shaft collar
Acceleration
Shaft vibration
Roller bearing housing
Casing
Velocity
Shaft vibration
Sleeve bearing housing
Casing
Proximity/Eddy Current Probe
The first choice to detect impending failures on sleeve
bearings. They must be drilled or tapped into the bearing
cap with proper gap voltage set. To allow Orbit or alignment
analyses it is recommended to install one sensor in X- and
one in Y-direction. The z-axis measurement is desired if an
axial thrust bearing is to be monitored.
Temperature
Bearing
Motor winding
Speed
Coupling
25
Signal analyses and display
4.5 %
4.0 %
3.5 %
3.0 %
2.5 %
2.0 %
1.5 %
1.0 %
0.5 %
0.0 %
-0.5 %
05.12.2003
07.12.2003
09.12.2003
11.12.2003
13.12.2003
15.12.2003
17.12.2003
18:00:00
18:00:00
18:00:00
18:00:00
18:00:00
18:00:00
18:00:00
Online shaft orbit plots
Trended bearing vibration monitoring
• For 2-dimensional shaft monitoring
• Screenshot of the PROGNOST®-NT VISU user interface
software showing the online orbit of 1 shaft revolution.
The slider allows to display consecutive revolutions.
• Peak vibration
• RMS vibration
• Amplitude of 1,2,3,4 ..10 harmonic of rotary frequency
Amplitude
Time
Harmonics 0.5x, 1.0x ... 10x
plus Subsynchronous
plus Non-Synchronous
3D waterfall Long time trend to detect
impending failures
Conclusion
PROGNOST®-NT is a fully capable and effective tool to monitor centrifugal and reciprocating machinery.
26
TI_PNT_2015_01_EN
3D orbit trend Long time trend to detect
impending failures
PROGNOST Systems GmbH
Daimlerstr. 10
48432 Rheine
Germany
+49 (0)59 71 - 8 08 19 0
+49 (0)59 71 - 8 08 19 42
info@prognost.com
www.prognost.com
PROGNOST Systems, Inc.
1018 Hercules
Houston, TX, 77058
USA
+1 - 281 - 480 - 9300
+1 - 281 - 480 - 9302
infousa@prognost.com