Miura LX Series Installation instructions

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STEAM BOILER INSPECTION MANUAL
MIURA BOILER Co.,LTD
MIURA MANUFACTURING AMERICA Co.,LTD
Boiler Inspection Manual Number : T519-998-9031 Date of issue : Sep. 15, 2009

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Table of Contents
Introduction......................................................................................................4
Basic Cautions.................................................................................................5
Inspection Flow Chart......................................................................................9
Bottom Blowdown Method.............................................................................10
1 BOILER VESSEL AND WINDBOX............................................................................. 14
1.1 Condition of Water-tube (Fire Side).................................................................. 15
1.2 Condition of Castable ........................................................................................ 16
1.3 Condition of Windbox Insulation Material........................................................ 17
1.4 Condition of Air Diffuser (EX Type Only) ......................................................... 18
1.5 Tightening the Windbox..................................................................................... 19
1.6 Inspection for Gas Leakage............................................................................... 20
1.7 Leakage from Joints (Water, Steam)................................................................. 22
1.8 Leakage of Exhaust Gas.................................................................................... 23
1.9 Inspecting the Safety Valve............................................................................... 24
2 BLOWER..................................................................................................................... 25
2.1 Condition of Air Filter......................................................................................... 26
2.2 Damper Operation.............................................................................................. 27
3 BURNER ..................................................................................................................... 29
3.1 Inspecting the Ignition Spark Cable.................................................................. 30
3.2 Inspecting the UV Sensor.................................................................................. 31
3.3 Inspecting the Pilot Burner................................................................................ 33
3.4 Inspecting the Main Burner ............................................................................... 35
4 FEED WATER............................................................................................................. 36
4.1 Cleaning the Feed-water Strainer...................................................................... 37
4.2 Cleaning the Surface-blowdown Strainer......................................................... 38
4.3 Inspecting the Electrode.................................................................................... 39
4.4 Leakage Test for the Feed-water Pump............................................................ 40
4.5 Checking Surface Blowdown Operation (Short-circuit Test).......................... 41
4.6 Checking for Check Valve Counterflow............................................................ 42
5 CONTROL................................................................................................................... 44
5.1 Checking the Steam-Pressure Switch Operation ............................................ 45
5.2 Checking Gas Pressure Switch and Airflow Switch Operations.................... 46

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5.3 Checking Feed-water Control Operation (Liquid Volume Control) ................ 47
5.4 Checking Safety Operations During Misfiring ................................................. 50
6 WATER ....................................................................................................................... 51
6.1 Collecting Boiler Water...................................................................................... 52
6.2 Measuring pH and Conductivity........................................................................ 53
7 MEASUREMENTS...................................................................................................... 54
7.1 Inspection for Boiler Interior ............................................................................. 55
7.2 Combustion Adjustment Procedure ................................................................. 58
7.3 Pilot Adjustment................................................................................................. 59
7.4 External Adjustment of the Pilot Burner .......................................................... 62
7.5 Main Burner Adjustment.................................................................................... 64
7.6 Adjustment of O2% and CO% in Exhaust Gas ................................................. 66
7.7 Measuring the Furnace Pressure...................................................................... 69
7.8 Inspection in Monitor Mode............................................................................... 70
7.9 Checking Smoke from Chimney........................................................................ 73
7.10 Measuring the Feed-water Pump Capacity .................................................... 74
7.11 Measuring the Supply Voltage ........................................................................ 75
7.12 Measuring the Motor Current .......................................................................... 76
8 OIL-FIRED BOILER.................................................................................................... 77
8.1 Checking Soot Deposits on the Water Pipes (Oil-fired Boiler Only).............. 78
8.2 Inspecting the Economizer (Oil-fired Boiler Only)........................................... 79
8.3 Removing the Burner (Oil-fired Boiler Only).................................................... 80
8.4 Inspecting the Burner (Oil-fired Boiler Only) ................................................... 81
8.5 Check Leakage from the Solenoid Valves (Oil-fired Boiler Only)................... 84
8.6 Testing the Ignition Transformer Capacity (EX-100 only)............................... 85
8.7 Cleaning the Oil Strainer.................................................................................... 87
8.8 Cleaning the Oil-Pump Filter ............................................................................. 88

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Introduction
Periodic boiler inspection shall be conducted to maintain safe and optimal operating conditions. This is the
most essential aspect of boiler maintenance. The inspector shall be experienced in the all operating
procedures and evaluation criteria. The inspector shall fulfill the true purpose of the inspection, without
omissions or errors. This manual is intended to integrate the operating procedures and evaluation criteria for
the main inspection items.
Boilers subject to inspection: the popular XJ1-specific microcomputer and BL boilers. The contents apply
to any model. This manual should be used in conjunction with the operator’s
manual to learn the inspection procedures.
The items relating to microcomputer specifications are limited to indications in the operator’s manual. Refer
to the specifications of respective boilers for details of evaluation criteria for the microcomputer.
Flow Sheet
SOFTENER
The feed water is normally hard
water. This is a device that softens
the hard water.
FEED-WATER TANK OR
DEAERATOR
Soft-water tank or deaerator
COLORMETRY
(HARD-WATER ALARM)
This is a device that monitors the soft
water treated by the water softener.
Remote alarm indication is available.
CHEMICAL PUMP
This is a device that feeds chemicals
to the feed-water tank or deaerator in
order to prevent boiler corrosion.
STEAM BOILER
The burner heats the treated water
which is fed into the water tube. The
heated boiler water evaporates
continuously and becomes steam,
which is supplied to the load side.
VENT CONDENSATE
RETURN STEAM
SOFTENER
COLORMETRY
(HARD-WATER ALARM) CHEMICAL PUMP FEED-WATER PUMP
ECONOMIZER
STEAM BOILER
FEED-WATER TANK
OR DEAERATOR

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Basic Cautions
I. Wear appropriate clothing and protective gear.
1) Do not wear bulky clothing or accessories that may
be caught by the valves or mechanical parts during
maintenance.
2) Do not wear clothing that contains flammable oil.
3) A clean working cloth makes a good impression and
helps prevent accidents.
4) Be sure to wear safety gear, including a hard hat,
safety shoes and gloves that are appropriate for the
nature of the work.
5) When handling chemicals (such as when repairing a
chemical feeder), be sure to wear protective glasses
and rubber gloves, etc.
II. Make sure you know the dangers inherent with a boiler before you work on it.
1) Inappropriate operation on the boiler may result in
death or serious injury. Be aware of high-
temperature and high-voltage areas, and explain the
risks to the user in order to prevent accidents.
Examples of Hazard
•Danger of burns
•Danger of breakage
•Disassembly prohibited
•Danger of electric shock
•Proper operation
•Inspection of safety valve
•Beware of rotating parts
WARNING
CAUTION

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III. Check the boiler installation conditions
Boiler room
1) Ensure that a ventilation fan and vent are providing
adequate air supply to and outlet for the boiler
exhaust.
Failure to provide adequate ventilation may cause
incomplete combustion and carbon monoxide
poisoning.
Boiler main unit
1) Ensure that the unit is properly secured with anchor
bolts at four locations.
Failure to secure the unit may allow the unit to tip
over or cause other accident.
2) Ensure that the unit is mounted on non-combustible
flooring material.
A floor made of wood or other combustible materials
may cause fire easily.
3) Ensure that flammable hazardous materials (i.e.
kerosene, gasoline) are not used in the boiler room.
4) Ensure that the boiler is located at the minimum
distance away from combustible materials according
to local code. As a rule, one shall instruct the user
not to place any combustible materials near the
boiler.
Fuel piping
1) Ensure that there is no leakage of fuel from the fuel
pipes.
2) Recommend that a gas-leakage alarm be installed
for LPG-fired boilers. As LPG is heavier than air, it
can accumulate on the floor and cause a gas
explosion.
The installation of an alarm is also recommended
for other types of gas.
Ventilation fan Air supply and
exhaust opening
Anchor bolt
Combustible material
Minimum distance
required by local
code
Combustibles
Gas-leakage alarm
Approx. 10"

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Safety-valve outlet
1) Ensure that the end of the outlet pipe is directed
to a safe area for steam discharge.
If the end directs a walkway or other equipment,
blowing steam may cause injury or damage to
the equipment.
2) Ensure that the pipe is properly secured during a
discharge.
Failure to secure the unit properly may allow the
pipe to move in reaction to a blowout, resulting in
bodily injury or damage to surrounding equipment.
Steam pipe
1) Reliable heat-insulation must be provided where
the steam pipe passes through a combustible
wall, etc. Failure to provide sufficient heat-
insulation may result in a fire.
Blowdown pipe
1) Physically touch the blowpipe to check that it is
properly secured.
Failure to secure the unit properly may allow the
pipe to move in reaction to a blowout, resulting in
bodily injury or damage to surrounding equipment.
2) Before draining the blowdown water, allow it to
cool to the temperature specified by local code.
Check the condition of the blowdown tank or
blowdown separator.
Check that the end of the blowout pipe opens into
a pit or other safe area.
DRAIN
SAFETY
RELIEF
VALVE
VENT-PIPE
SUPPORT
SLIP ONTO THE
DRIP PAN
ELBOW
DRIP PAN
ELBOW
UNION
UNION/FLANGE
OUTDOORS
Heat insulation
Wall
Pit
Blowdown pipe

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Electrical work
Failure to follow the warning signals for electrical work
may result in a short circuit, electrical shock, or fire.
1) Ensure the power source for the boiler has a
dedicated circuit breaker.
2) Ensure the power wire diameter and breaker
capacity meet the specifications.
3) Ensure the grounding wire is connected to the
grounding terminal inside the boiler control box.
Exhaust tube
1) Ensure the materials are non-combustible where the
exhaust tube passes through.
Use of combustible materials may result in a fire.
2) Ensure that there are no combustible materials
around the end of the exhaust tube. Use of
combustible materials may result in a fire.
3) Ensure the hole is sealed and secured where the
exhaust tube passes through.
Inadequate sealing may result in carbon monoxide
poisoning due to the leakage of exhaust gas.
The precautions mentioned above are basic precautions.
Be aware of all relevant factors in the field. Moreover,
consent to all local codes.
Ground
Grounding
terminal
6" all round Exhaust tube
Non-combustible
materials
3 ft.
3 ft.
or more
2 ft.
or more

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Inspection Flow Chart
Clean the
oil-pump filter
Clean tip of
burner nozzle
Cracking of
ignition insulator
Check nozzle
tip standard
Adjust burner
nozzle dimensions
Check set value of
chemical feeder dial
Check chemical
and salt amounts
Clean boiler area
Prepare inspection
report
User questions and
training
End
Dial set value
Clean inlet-port
filter
Chemicals
1
3
B
C
C
A to E
dimensions
For regenerating water
softener operation
*
*
* * Only for OIL-FIRED BOILER
YES
NO
NO
OK
OK
OK
P.89
P.82
P.30
P.82
P.73
P.52
P.85
P.53
P.19
P.40
P.79
P.38
P.27
P.58
P.52
P.45
P.39
P.42
P.74
P.36
P.42, 53
P.15
P.30
P.31
P.50
P.20
P.24
P.18
P.17
P.16
P.26
P.25
P.54
P.74
P.72
Replace
YES
Clean after
disassembly and
replacement
NO
OK Check and
replace
Check non-ignition
operation
Check abnormal
quenching operation
Check gas-leakage
condition
Check safety
valve
Install burner
nozzle
Tighten windbox
bolt
Clean chimney
elbow
Condition of dust
on economizer
Run boiler
Check damper
operation
Check for abnormal
noise in blower
Regulate burning
Check operation of
TDS controller
Check operation of
steam pressure
switch
Check for leakage
from electrode
Check for leakage
of check valve
Measure capacity
of feed-water pump
Check safety
starting operation
Check UV
sensor
voltage
Timing until
Alarm
Check Hi limit
TC and scale
monitor TC
Pre-purge
Post-purge
Su
pp
l
y
volta
g
e
Gas differential
pressure, oil
pressure, CO2,
smoke, furnace,
pressure,
exhaust
temperature
Ignition
frequency
Burn timer
Temperature of
feed water
Ignition trial
timing
Safety-switch
timing
Safety-switch
timing
Soft-water
check
Check discharge
condition of
chemical feeder
Ignition-transformer
spark test
Clean ejector after
disassembly
Check operational
condition of salt-
water valve
Check regeneration
operation (manual)
2
2
Leakage from the
shutoff valves

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Bottom Blowdown Method
Difference between Complete Bottom Blowdown and Partial Blowdown
Two methods are available for removing boiler sludge. To properly evaluate which method to use, the
operator needs to consider a number of factors, including water quality, potential increase or decrease in pH,
timing of blowdown, hours of operation, and operating requirements. After conducting a complete bottom
blowdown, the pH and conductivity inside the boiler become the same as the feed water. This low pH and
low conductivity situation can cause corrosion. Therefore, a complete bottom blowdown should be conducted
only before running the boiler.
Complete Bottom Blowdown
Timing of blowdown
Conduct this process when the “B-BLOW Required” lamp on the control panel lights. The XJ1 calculates this
caution according to the equivalent high-fire operation hours. The timing setting can be changed under
“Setting data” on the XJ1.

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Procedure
1) If the steam-pressure gauge indicates 20 to 30 psi, go to step 5. Else, go to step 2.
2) Open the air-vent valve to release the vacuum.
3) Open the feed-water valve and fuel valve. The main steam valve remains closed.
4) Turn ON the operation switch to start feeding water. Push the combustion switch once to fire the boiler.
The XJ1 displays “STANDBY,” which changes to “PREPURGE” when the combustion cycle begins.
When the steam-pressure gauge indicates 20 to 30 psi, push the combustion switch once to take the
boiler out of firing mode. Turn OFF the operation switch after the blower stops: the XJ1 displays
“DISABLED”.
5) •Make sure the blowdown pipe is properly secured.
•Ensure there is no danger of burn injuries due to the splashing of scalding water blowing from the
end of the blowpipe.
If it is safe to blowdown the scalding water, gradually open the blowdown valve (until it is fully open)
and drain the boiler water completely.
6) After draining the water, close the blowdown valve and turn ON the operation switch. The XJ1 displays
“ENABLE” and the feed-water pump starts.
7) Before the feed water level reaches the L-probe, push the combustion switch once to confirm that the
boiler does not start the combustion cycle before the water has reached the L-probe level.

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Partial Bottom Blowdown
Timing of blowdown
Same as Complete bottom blowdown.
Procedure
1) Follow the same steps as the complete bottom blowdown when the boiler is started, except:
Open the blowdown valve for only 30 seconds. The idea is to lower the water level below the
conductivity sensor. This can be verified by watching the Conductivity level on the XJ1. When the XJ1
Conductivity reads “--”, the conductivity sensor is dry and the boiler may be restarted normally.
LVC blow-down valve
Steam vessel blow-down valve
Second valve for safety

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BL
The purpose of blowdown is to eject boiler sludge from the boiler shell, to control the concentration of boiler
water and its pH.
When the boiler is shut down or in standby mode, the boiler water has a high pH and low amount of
dissolved oxygen. This water does not readily cause corrosion to the boiler.
Blowdown: Mainly effective for ejecting boiler sludge which is suitable for users who concern about freezing
or scale buildup.
Blowdown should be conducted before boiler starts and/or between operation (lunch, break) if possible. Try
to avoid blowdown operation after working hours.
If blowdown has to be conducted after work hours, do not feed water back until the next boiler operation.
Fresh feed water will create an environment that will cause corrosion in the idle boiler. Feed water to the
boiler prior to operation again.
Blowdown timing
When the yellow indicator lamp lights and “B/DOWN
REQUIRED” is displayed that indicates blowdown is
required. Also, when B appears on the display during
boiler starts, blowdown is required.
The blowdown timing indicator B is displayed when the
number of equivalent high fire operation hour(s) has
exceeded the BL equivalent high fire operation hour
preset limit.
Blowdown procedure
1) If the steam-pressure gauge indicates 20 to 30
psi, go to step 5. Else, go to step 2.
2) Open the boiler air relief valve to release the
vacuum.
This step can be omitted if the pressure gauge
reads 0 psi, or above (pressure exceeds
atmospheric pressure).
3) Open the feed-water valve, feed-water stop
valve, and main fuel valve.
However, close the main steam valve.
4) Turn ON the operation switch to feed water.
5) Boiler combustion starts after water is supplied.
Turn OFF the operation switch when the steam
pressure gauge reaches 20 to 30 psi.
Wait until the fan stops.
6) Ensure it is safe to discharge the blowdown
water. Slowly open the blowdown valve until it is
fully open.
•Ensure the blowdown pipe is securely
fastened.
•Discharge the pipe where hot water from it
cannot splash and cause burn injuries.
7) Close the blowdown valve when B disappears
from the display.
The blowdown procedure is now completed.

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1 BOILER VESSEL AND WINDBOX

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1.1 Condition of Water-tube (Fire Side)
Procedure
Confirm the following four conditions.
•Operation switch: OFF •Combustion-source valves: “Closed”
•Burner is removed. •The boiler is sufficiently cool to work with.
1) Light the interior of the furnace with a work light and check there is no deformation of the water tubes.
2) Check the upper area of the water tubes using the inspection light and a reflective mirror.
Evaluation criteria
1) Check the combustion-gas path. There should be no bending of the water tubes or variation in the
clearances between them.
The layout of the water tubes varies between the boiler models. Water tube clearance in unique in
each model, confirm the abnormality is valid.
If deformation is discovered in the water tubes, identify the cause, take photos, and ask MIURA
technicians for instructions. Leaving this problem untreated can lead to a dangerous condition. Prompt
action is necessary.
A
LX
LX (view from A)
WX (troika flow)
EX (omega flow)

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1.2 Condition of Castable
Procedure
Inspect the condition of the castable while inspecting the condition of the water tubes.
1) Light the interior of the furnace with a work light and inspect the castable at the bottom of the furnace
for cracking or disengagement.
2) Check the castable at the top of the furnace for cracking or disengagement using the inspection light
and a reflective mirror.
Evaluation criteria
1) If cracking or disengagement of the castable is detected, repair it immediately.
2) If disengagement is particularly significant, take photos, and ask MIURA technicians for instructions.
Castable CA-10Z（ASAHI GLASS CERAMICS）for repair
(1) When you install new castable on existing castable.
Water volume 0.18～0.20 Litter／kg (castable)
(2) When you install new castable on the metal plate (No old casatable remaining)
Water volume 0.14～0.16 Litter／kg (castable)
Castable
Castable
Water tube
Inspection ligh
t

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1.3 Condition of Windbox Insulation Material
Procedure
Inspect the condition of the windbox insulation material while inspecting the condition of the water tubes.
1) Light the interior of the furnace with the work light and check that none of the insulation material has
dropped to the bottom of the furnace.
2) Check the bottom of the windbox for any separation of the insulation using the inspection light and a
reflective mirror.
Evaluation criteria
1) If any insulation is discovered at the bottom of the furnace, remove it if possible. Loose insulation can
cause blockage between the water tubes.
Promptly repair the area where the insulation separated from the windbox.
Insulation material Inspection light
Insulation material
for the windbox
Work light

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1.4 Condition of Air Diffuser (EX Type Only)
Procedure
Conduct this check when checking the condition of the water tubes.
1) Using a work light or inspection light, ensure that there is no deformation or burning due to overheating.
Note) The air diffuser is extremely hot immediately after the combustion. Inspect the air diffuser
after it has cooled down enough to be touched with bare hands.
Evaluation criteria
1) If deformation or burning has occurred due to overheating, replace the air diffuser promptly. If this
problem was caused by excessive combustion or improper burner installation, the problem will reoccur.
Replace the diffuser after confirming the cause of the problem and taking the necessary action.
Note) The air diffuser is subjected to high temperatures and
can become deformed, as shown in the photograph to
the right. This diffuser needs to be replaced.
Main burner
Wind box
Economizer Pilot burner
A
ir diffuser
Separator
Top casing
Insulator
Casing
Inner casing
Water tube
Fiberglass
Castable
Header

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1.5 Tightening the Windbox
Procedure
1) Using an offset wrench, tighten the fixing bolts for the windbox diagonally several times so that they
are evenly tightened.
Evaluation criteria
1) Tighten evenly, as a loose windbox fixing bolt may cause combustion-gas leakage.
2) If combustion-gas leakage occurs, replace the windbox packing when the windbox packing is
deformed.
For your information
1) It is ideal to replace the windbox packing regularly. (Once every three years is recommended.)
Windbox
Fixing bolt

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1.6 Inspection for Gas Leakage
Inspection procedure
1) Close the main gas valve and pilot gas valve.
Install a vinyl hose onto tailpiece adaptor and immerse the other end in water partially filled with
glycerine. Collect the gas in a measuring cylinder.
When a measuring cylinder is not available, calculate the amount of gas leakage using the following
simplified calculation:
the volume of one bubble is 0.30 ml for a bore diameter of 0.39 inch, or
0.22 ml for a bore diameter of 0.24 inch.
2) Open the main gas valve. Check the gas pressure with a pressure gauge, close the main gas valve,
and wait at least five minutes. Check for a drop in pressure. (A pressure drop indicates that gas
leakage is occurring.)
Open the main gas valve and investigate the site of the gas leakage.
3) If there are any gas bubbles, repair is needed.
Additional check: Check for gas leakage between the shutoff valves and burner using a gas-leakage
detector while firing the boiler. When a detailed investigation is necessary, ask
MIURA technicians for the proper procedure.
In the event of an abnormality
When there is a potential gas leak yet no gas can be collected using the above method.
Actions
Pipe-joint area: Investigate the pipe-joints using soapy water, and then repair the leak.
Areas to which soapy water may not be applied, including the gas-pressure switch: Investigate the site of
leakage using a gas-leakage detector, and then repair the leak area.
External gas leakage is not allowed. If leakage occurs, the boiler must not be operated.
If gas leaks into the measuring cylinder, it is suspected that gas is leaking from the shutoff valves.
Actions
Disassemble the shutoff valves. Repair or replace the valves.