VYC 003 Service manual

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Ultrasonic leak detector. Mod. 003.
To detect leaks:
In condensate purgers
In valve seals
Checking for wear on bearings
Solving mechanical problems in general

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Safety warning
Please read this before using your Detector
WARNING!
Misuse of the Ultrasonic leak detector could result in death or serious injury. Please follow all the
safety instructions. Do not try to carry out repairs or adjustments while the equipment is in
operation. Make sure that you turn off and block all the electrical and mechanical sources before
doing any corrective or preventative maintenance work. Always check local guidelines on
maintenance and prevention.
Safety instructions:
Although the Ultrasound leak detector is designed to be used when the equipment is in operation,
the proximity of hot pipes, electrical equipment and rotating parts is potentially dangerous for the
user. Take great care when using the Detector close to energized equipment. Avoid direct contact
with hot parts or piping, any part in movement and electrical connections. Do not try to confirm the
results by touching the inspected equipment with your hands or fingers. Make sure that you use
the appropriate lockout procedures when carrying out repairs.
Take care with loose hanging parts, such as the wrist strap and the headphone cable, when
carrying out inspections near moving mechanical devices, since these elements may become
trapped. Do not touch moving parts with the ultrasonic probe. This will not only damage the part
and the Detector, it could also cause personal injury.
Wear the appropriate protective clothing. Do not get too close to the point of verification. Your
Detector can locate problems from a distance. Take care when working around high temperature
pipes. Wear protective clothing and do not try to touch any of the pipes or equipment while they
are hot. Check with your safety officer before entering the work area and follow all the safety
procedures.

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Index
Page
1. Ultrasonic leak detector. Mod.003 4
2. Table of contents 5
Components 5
Measuring gun 5
oBargraph display 5
oBattery life display 5
oSensitivity selector 5
oConnector for headphones 5
oSwitch 5
Stethoscope module 6
Headphones 6
3. Uses of the Ultrasonic leak detector. Mod.003 6
3.1. Detection of leaks in condensate purgers 6
Confirmation of: Steam/ Condensation/ Flash Steam 7
Inverted floater purger 7
Closed buiy purger with a thermostatic element 8
Thermodynamic purger 8
Thermostatic purger. (Bimetallic or with balanced element) 8
3.2. Detection of leaks in valve seals 9
Detecting bearing faults 9
Confirming a leak 10
3.3. Checking for wear on bearings 10
Detecting bearing faults 11
Low velocity bearings 11
4. Solving general mechanical problems 12
Solving problems 13
5. Ultrasound technology 13
6. General catalogue 14

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1. Ultrasonic leak detector. Mod. 003
It provides a simple way to detect leaks and carry out accurate mechanical inspections using
advanced ultrasound technology.
Before you start taking measurements, we recommend that you first familiarize yourself
with the components of your equipment.

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2. Table of contents
· Components
· Measuring gun
The main component of the Detector is the ultrasound gun. We will examine each part from back
to front.
· Bar graph display
The screen contains a bar graph display with ten LED segments which indicate the intensity of the
ultrasound signal. If only a few LEDs are lit up, this indicates a low level of ultrasound, while more
intense ultrasound signals will lead to a large number of LEDs being lit up.
· Battery life display
This red light only comes on when the batteries need recharging.
NOTE: When the on/off switch is moved to the "on" position, the battery life light will flash before turning off
again. This is normal and does not indicate the condition of the battery.
· Sensitivity selector
There are eight (8) levels of sensitivity that are read in decibels displayed from "0" to "70". As the
dial is turned to the right, toward "0", the sensitivity of the instrument increases. As the selector is
turned to the left, toward "70", the sensitivity will decrease. A low level ultrasound emission
produces low amplitude. To detect low level ultrasounds, the instrument must be in a position of
high sensitivity. 0 is the highest sensitivity setting. For higher amplitude signals, move the
sensitivity to the left towards the "70".
Combination of the bar graph display and sensitivity selector: Each bar lit up in the bar graph is
equal to 3 dB. Example A: Sensitivity selector set at 0 dB and the LED bar graph has 3 bars lit, so
the total reading is 0 dB+9 dB=9 dB. Example B: Sensitivity selector set at 40 dB and the bar
graph has 4 bars lit, so the total reading is 40 dB+12 dB=52 dB.
· Connector for headphones
This is where the headphones are connected. Ensure they are connected firmly, until you hear a
click. If you are going to use a recorder, please insert the connector cable here. (It uses a
Miniphone connector).
· Switch
This is found at the bottom of the Detector. The Detector is always "switched off" until this switch
is pressed. To operate it, simply press the switch, and release the switch to turn off the instrument.

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· Stethoscope module
This is a module with a long metal probe. This probe is used as a "wave guide" and is sensitive to
the ultrasounds generated internally, such as inside a pipe, the housing of a bearing, condensate
purgers, valves, etc. Once stimulated by the ultrasound, it transfers the signal to a piezoelectric
transducer placed directly in the casing of the module.
To use the stethoscope module:
1. Align the pin located in the rear of the module with the connector found in the tip of the gun and
plug in firmly.
2. Touch the area to test or inspect.
3. Start with a maximum sensitivity in the sensitivity selector and reduce the sensitivity until you
have a satisfactory sound and the level of the meter is reached.
The probe is removable and can be replaced with two or three pieces of probe to achieve different
lengths for the stethoscope.
· Headphones
They are highly resistant headphones designed to block out loud sounds in industrial
environments. They allow the sounds received through the detector to be clearly distinguished.
Connect the headphone cable to the connection located in the measuring gun and place the
headphones over your ears.
IMPORTANT: They are compatible with the security helmet.
3. Uses of the Ultrasonic leak detector. Mod.003
3.1. Detection of leaks in condensate purgers
An ultrasonic test of the condensate purgers is a test that all users of purgers should frequently
perform as a preventative measure. It is a problem of energy efficiency and environmental
awareness, and of course also one of financial savings.
The user will become familiar with the different types of purgers and will know how to recognise
them with great ease.
We should remember that there are three types of purgers:
Thermodynamic
Mechanical (closed buoy and inverted floater)
Thermostatic (bimetallic and balanced element)

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Before starting to detect a leak:
1. Determine what type of purger is in the line. Familiarise yourself with the way the purger works.
It is intermittent or continuous drainage? We should easily recognise the operating sound of each
type.
2. Try to check whether the purger is in operation. Place your hand close to it, but do not touch the
purger, or even better, use a non-contact infra-red thermometer to check if it is hot or cold.
3. Use the stethoscope module.
4. Try to use the probe of the module to touch the discharge side of the purger. Press the switch
and listen.
5. Listen to the intermittent or continuous flow operation of the trap.
Intermittent flow: Inverted floater, thermodynamic and thermostatic.
Continuous flow: Closed buoy with a thermostatic element.
While testing intermittent purgers, listen long enough to measure the true cycle. In some cases
this can exceed 30 seconds. Bear in mind that the greater the load reaching the purger, the more
time it will remain open.
When carrying out an ultrasonic test of a purger, a continuous running sound usually indicates the
passing of steam. There are subtleties with each type of purger that should be taken into account.
Use the sensitivity levels of the Sensitivity Selector to help with your examination. If we are going
to inspect a low pressure line, adjust it for greater sensitivity, toward the "0". If it is a medium
pressure system (over 6-8 bar), reduce the sensitivity level toward "80".
Check upstream and reduce the sensitivity so that the indicator is at around 50% or less. Next,
touch the body of the trap downstream and compare the readings.
Only practice will help here, and we will need lots of it to reach an appropriate level of inspection.
· Confirmation of: Steam/Condensation/Flash Steam
In the cases where it is difficult to determine the sound of steam, flash steam or condensate:
1. Touch the immediate downstream side of the purger and reduce sensitivity to obtain a reading
on the meter midline (approximately 50%).
2. Move between 15-30 cm (6-12 inches) downstream and listen. Flash steam will show a large
drop in the intensity, while exiting steam will show a slight drop in intensity.
· Inverted floater purger
Operates with an inverted floater that moves as a result of the difference in density between the
condensate and the steam. When there is condensate the floater lowers, it frees the seat valve
and allows the condensate to exit. When steam enters, the floater rises and blocks the pathway,
guaranteeing a line free of condensates. This action is repeated cyclically, automatically removing
the accumulated air and condensates.

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The inverted floater purger operates intermittently. If steam is leaking through the valve, we will
detect the loss of this intermittent nature and the escape sound will be strong and continuous.
· Closed buoy purger with a thermostatic element
Operates with a float valve that opens up for the accumulation of condensates and transports it. It
also incorporates a thermostatic element that allows for the automatic elimination of air.
A closed buoy purger normally has a fault in the "closed" position. The valve is damaged or the
thermostatic element leaks.
If there is a leak through the valve, the sound will be constant and easy to hear.
If there is no leak through the valve and we detect the passing of steam, the leak must come from
the thermostatic element.
You are wasting energy.
· Thermodynamic purger
The operation of a thermodynamic purger is based on the "Bernoulli" principle: "In a fluid in
movement, the sum of the static and dynamic pressures remains constant at all points. So if one
increases, the other decreases and vice versa".
The input pressure acts on the shut-off disc, which allows for the immediate discharge of
condensate and air at the temperature of steam.
The steam then enters the purger. The high speed produced by the expansion of the steam
creates a low pressure area at the rear of the shut-off disc.
The flow is diverted to the back of the shut-off disc and creates a high pressure zone through
recompression. The shut-off disc starts to lower.
When the high pressure is acting on the entire surface of the shut-off disc, it exercises a force
greater than the input pressure. The purger closes. The subsequent presence of condensate in
the entrance repeats the cycle.
A thermodynamic purger in good condition has a cycle (retention-discharge-retention) of 4-10
times a minute. In general, when there is a fault this is in the open position, allowing for a
continuous stream of steam.
· Thermostatic purger
All thermostatic purgers work on the basis of the difference in temperature between the
condensate and the steam.
· Bimetallic purger:
A bimetallic purger works on the basis of the principle of the combination in a column of metallic
discs of two faces in a single bimetal, where each face has a different expansion coefficient.
The bimetals are stacked in pairs, with the faces with the same coefficient (faces without notches)
facing each other.

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In the presence of cold water, the bimetals remain flat. On detecting a higher and higher
temperatures, they become deformed in a convex shape, moving the seat against the valve.
Maximum convexity, and with it, a totally watertight seal, is obtained just at the mid-point of
moving from condensate to steam.
· Thermostatic purger with balanced element:
The thermostatic action of the balanced element allows the condensate and cold air to freely leave
when starting up.
When the temperature of the condensate reaches that of saturation, the element closes and
blocks the steam.
When the condensate cools, the elements opens and evacuates it. When steam is at the point of
appearing, the cycle is repeated and the element closes, and so on.
If the purgers have a fault, you will hear a constant leak noise.
3.2. Detection of leaks in valve seals
When a low pressure fluid escapes through a small space, it moves from a laminar flow to a
turbulent flow. The turbulence generates a wide spectrum of sound known as "White Noise".
As the ultrasound will be stronger at the location of the leak, the detection of the signal is relatively
easy.
In the case of a valve where the valve is leaking, the fluid that escapes will move from an area of
high pressure to one of low pressure, creating turbulence in the low pressure or "downstream"
side. The ultrasonic component of this "White Noise" is much stronger than the audible
component. If the valve has an internal leak, the ultrasonic emissions generated in the location of
the orifice will be heard and registered by the meter.
The sounds of a valve with a leak can vary depending on the density of the fluid. In some cases, a
subtle crackling sound will be heard, other times there will be a loud sound of leakage. Sound
quality depends on the viscosity of the fluid and internal pressure differentials of the pipe.
As an example, water flowing at low or medium pressure can be easily recognised as water.
However, high pressure water running through a partially open valve may sound very much like
steam. To discriminate between them: reduce the sensitivity, touch the line of steam and listen to
the quality of the sound, then touch a line of water. Compare and once familiar with the sound
differences, continue your inspection.
A correctly positioned valve will not generate any sound. In some high pressure situations, the
ultrasound generated within the system will be so intense that the surface waves will move from
other valves or parts of the system and make it difficult to diagnose the leaks in the valve. In this
case we make a comparison of sonic differences by reducing the sensitivity and touching the
upstream part of the valve, in the valve seat and just downstream of the valve.
· How to locate leaks
1. Use the stethoscope module and the headphones.
2. Start with the sensitivity selector at 0 (Maximum).

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3. Start to scan, directing the module downstream of the valve and listen through the headphones.
4. If you detect a lot of ultrasound in the area, reduce the sensitivity adjustment and continue
scanning.
5. Try to listen for an "escape" sound while watching the meter.
6. Follow the sound to the point where it is the strongest. The meter will show a higher reading
the closer you are to the leak.
7. In order to focus on the leak, keep reducing the sensitivity and work on the suspect area until
finally in a position to confirm whether one exists.
8. For comparative readings, generally in high pressure systems:
1. Touch the upstream area and reduce the sensitivity to minimize any sound (in general,
set the meter at the midline "50%" reading).
2. Touch the valve seat area and/or the downstream side.
3. Compare the sonic differences. If the valve has a leak, the sound level in the seat or
downstream side will be equal to or greater to that of the upstream side.
· To confirm a leak
In high pressure systems, there can be parasite signals or false signals produced by nearby valve
or pipes. In order to determine whether the signal analysed comes from a valve being inspected,
proceed as follows:
1. Move closer to the suspect source.
2. Touch the upstream side of the suspect source.
3. Reduce the sensitivity until the meter shows a midline "50%" reading.
4. Touch it in short intervals, for example every 15-30 cm (6-12 inches) and watch for changes in
the meter.
5. If the level of sound reduces as it is moved towards the valve to be tested, this indicates that
the valve has no leaks.
6. If the level of sound increases as it is moved towards the valve to be tested, this indicates that
the valve has a leak.
3.3. Checking foe wear on bearings
The ultrasound inspection and monitoring of the bearings is the most reliable method of detecting
incipient faults in the bearings.
The ultrasonic warning appears in response to an increase in the temperature or the increase in
low frequency vibration levels.