Miura LX Series User manual

Please ensure that operation manual is read and observed in
full by all persons working with the steam boiler.
Please also ensure that it is stored in a location where it may
be easily accessed by said persons.
INFORMATION IN THIS MANUAL MAY BE CHANGED
WITHOUT ANY NOTICE.
MIURA STEAM BOILER
OPERATION MANUAL
LX-50 LXL-50
LX-100 LXL-100
LX-150 LXL-150
LX-200 LXL-200
LXH-200 LX-300
LXH-300
Operation Manual Number
:
T5
1
9
-
998
-
9
0
0
7
Date of issue : Aug. 16, 2017

1
Main Sections
1. INTRODUCTION 4
2. ESSENTIAL BOILER WATER TREATMENT 14
3. COMPONENT NAMES & FUNCTIONS 20
4. BASIC PRECAUTIONS 25
5. PRE-OPERATION INSPECTION 31
6. USING BOILER CONTROLS 35
7. PREPARING FOR STARTUP 46
8. OPERATING THE STEAM BOILER 49
9. INSPECTION & MAINTENANCE 53
10. BREAKDOWN & COUNTERMEASURES 71
11. SPECIFICATIONS 81
12. APPENDIX 84

2
Table of Contents
Main Sections ......................................................................................................................................... 1
1 INTRODUCTION ............................................................................................................................. 4
Safety Indicators ................................................................................................................................. 5
Glossary .............................................................................................................................................. 6
Warranty .............................................................................................................................................
Introduction ........................................................................................................................................
Features .............................................................................................................................................. 8
Description ........................................................................................................................................ 10
Acts & Regulations ........................................................................................................................... 12
National Regulatory Organizations ................................................................................................. 13
2 ESSENTIAL BOILER WATER TREATMENT .............................................................................. 14
2.1 Flow Chart .................................................................................................................................. 15
2.2 Water Treatment Guidelines ...................................................................................................... 1
3 COMPONENT NAMES & FUNCTIONS ...................................................................................... 20
4 BASIC PRECAUTIONS ................................................................................................................. 25
Items to Check before Use ................................................................................................................ 26
Clothing Requirements for Safe Operation ..................................................................................... 2
Warning Labels ................................................................................................................................. 2
Dealing with Abnormal Conditions.................................................................................................. 28
Precautions for Boiler Usage ........................................................................................................... 29
Fire Extinguishers & First Aid Boxes ............................................................................................. 29
Prohibition of Unapproved Modification ......................................................................................... 30
When Reselling or Relocating .......................................................................................................... 30
5 PRE-OPERATION INSPECTION .................................................................................................. 31
6 USING BOILER CONTROLS ........................................................................................................ 35
Names & Functions of Control Panel Items .................................................................................... 36
Working with the Display ................................................................................................................ 3
6.2.1 Display Content ............................................................................................................... 3
6.2.2 Using the Display (“DATA” & “SELECT”) ...................................................................... 38
6.2.3 Display Content for Heat Management Mode ................................................................ 39
6.2.4 Display Content for User Setting Mode.......................................................................... 40
6.2.5 Display Content for Fault History Mode ........................................................................ 43
Confirming Gauge Readings ............................................................................................................ 44
Operating the Main Steam Valve .................................................................................................... 45
PREPARING FOR STARTUP ........................................................................................................ 46
8 OPERATING THE STEAM BOILER ............................................................................................. 49
8.1 Boiler Startup ............................................................................................................................. 50
8.2 Inspection during Operation ...................................................................................................... 51
8.3 Boiler Shutdown ......................................................................................................................... 52
9 INSPECTION & MAINTENANCE ................................................................................................ 53
Preparing for Possible Freezing ....................................................................................................... 54
9.1.1 Bleeding Water to Protect against Freezing ................................................................... 54
Maintenance during Extended Inactivity ........................................................................................ 55
Regular Maintenance Tasks and Timing ......................................................................................... 56
Spare Parts ....................................................................................................................................... 58
Overview of Inspection ..................................................................................................................... 59
9.5.1 Checking the Chemical Feeder ....................................................................................... 59

3
9.5.2 Checking the Water Softness .......................................................................................... 60
9.5.3 Checking the Gas Pressure ............................................................................................. 61
9.5.4 Checking the Steam Pressure ......................................................................................... 61
9.5.5 Blowdown & Testing of the Low Water Level Interlock ................................................. 62
9.5.6 Cleaning the Air Filter .................................................................................................... 64
9.5. Cleaning the Feed-water Strainer .................................................................................. 66
9.5.8 Cleaning the Feed-water Tank ........................................................................................ 68
9.5.9 Inspecting the Safety Valve ............................................................................................. 69
9.5.10 Safety Sensors Check ...................................................................................................... 0
10 BREAKDOWN & COUNTERMEASURES ................................................................................ 1
10.1 Alarm and Red Status Lamp – Alarm ................................................................................ 2
10.2 Yellow Status Lamp – Caution ............................................................................................ 3
10.3 Action to be Taken before Ordering Repairs ...................................................................... 4
10.3.1 Bleeding Air from the Feed Water Pump ................................................................... 8
10.3.2 Inspecting Water Level Probes ................................................................................... 9
10.3.3 Resetting the High Pressure Limit Shutoff Switch ................................................... 9
10.3.4 Resetting Blower Overcurrent .................................................................................... 80
11 SPECIFICATIONS ...................................................................................................................... 81
12 APPENDIX .................................................................................................................................. 84

4
1 INTRODUCTION

5
Safety Indicators
The following headings are used within this manual in order to ensure safe and efficient operation of your
steam boiler.
Please ensure that you fully understand the meaning of each and use the boiler accordingly.
WARNING
CAUTION
NOTE
Meaning of safety
indicators
The number contained within this symbol indicates a relevant
page.
This symbol is used to indicate forbidden actions.
Specific details of these actions will be presented together with
the symbol.
Important information from the point-of-view of
preventing boiler malfunction and ensuring
efficient operation, or information that will prove
useful during operation of the steam boiler.
Failure to use the steam boiler correctly could
possibly lead to injury of the user or to property
damage.
Failure to use the steam boiler correctly could
possibly lead to serious injury or death of the
user.

6
Glossary
Please use the following table to confirm the meanings of special terms used within the operation manual.
Term Meaning
Low water level
interlock
The action of preventing ignition when the normal water level has not been
achieved.
Pre-purge
Purging with air from the boiler’s combustion chamber before the start of
combustion.
Post-purge Purging with air from the boiler’s combustion chamber after the end of
combustion.
Pilot ignition Ignition of the pilot burner.
Pilot only A condition wherein only the pilot burner is lit.
Main ignition Ignition of the main burner.
Low fire A condition wherein combustion takes place at between 33 to 65% of maximum
combustion performance. (firing rate depends on models)
High fire A condition wherein the boiler is operating at maximum combustion
performance.
Scale The buildup of water impurities such as calcium and magnesium on water
tubes.
Sludge Impurities that precipitate inside the boiler.
Untreated water Water that has not yet been treated.
Soft water Water which has had calcium and magnesium removed.
Boiler makeup (water) Treated water that is supplied to the boiler, or the act of sending this water.
Equivalent evaporation The mass of steam generated in one hour when water at 212°F is changed into
steam at 212°F.
Carry over The unwanted discharge of moisture or impurities in the steam.
Blowdown The discharge of water contained within the boiler.
Water tube A tube making contact with combustion gas on the outside, and through which
boiler water flows.
Deaerator A device used to heat the boiler makeup water in order to reduce the level of
oxygen dissolved in it.
Cavitation A situation where air enters a pump and prevents normal operation.

7
Warranty
Please review the twelve month boiler warranty carefully so (you) the end user is aware of your
responsibilities and what is covered under this warranty. Below are a few points to ensure the warranty is
fully understood.
1. The warranty covers defective workmanship and materials NOT mis-use of the boiler.
2. Miura must approve the start-up and have a signed start-up report on file.
3. End User Responsibility: Water hardness must be tested EVERY day.
4. End User Responsibility: In addition to a daily hardness check, water quality must be tested
every four months because the quality of water sources changes from season to season. This is
to include a full water test (not just hardness). Test result should be compared to STANDARD
BOILER WATER SPECIFICATIONS FOR MIURA BOILERS shown in this manual.
5. End User Responsibility: Keep a log of the hardness tests and full water quality tests.
Note: One of the most common causes of boiler damage is due to the build up of scale. This is why the
water hardness should be tested daily. The conventional test method for hardness is a manual test. Results
can vary due to sample and reagent amounts, personal interpretation, and lack of continuity in monitoring
hardness. An optional MIURA Colormetry solves all these problems by offering an automatic monitoring
system for sample water collection, chemical reagent injection, mixing and evaluation. With this option, the
MIURA boiler will also display the message “CAUTION – CHECK SOFTENER” whenever the MIURA
Colormetry detects hardness leakage through the water softening system.
Introduction
MIURA Boiler Co., Ltd. began North American activities in 1988, when the manufacturing plant in Brantford,
Ontario, was established. Subsequently, our engineering department developed procedures to meet ASME
codes and to gain listing approval from UL, CSA. The United States corporate sales office, MIURA Boiler,
Inc., was then established and has since developed relationships with national, state and city inspectors and
agencies.
Our North American network consists of branches in Atlanta, Chicago, Los Angeles, New York, Texas, and
Ontario. The parent company, MIURA Boiler Ltd. of Japan, is the leading manufacturer of boilers and other
thermal equipment in the Pacific Rim region with market share in excess of 55%. Operating factories in five
countries, our production volume now exceeds 14,000 units per year.
As a result of design necessities in Japan — such as limited space and a total dependence on foreign
energy — the MIURA Steam Boiler has been engineered with a highly efficient, vertical water tube, once-
through, forced-flow design. Featuring a compact unit with low water content, the MIURA Boiler is designed
to be run with simple push-button controls and a minimum amount of maintenance. Operation is quiet,
radiant heat losses are minimal, and steam quality is second to none. Furthermore, MIURA Boilers are often
installed in a multiple boiler network.
MIURA Boilers, in combination with the patented MIURA Multiple Installation panel, allow the required
horsepower to be brought on and off line quickly in order to meet sophisticated production needs with
maximum fuel economy. The MIURA Advantage — proven in the field over fifty years of excellent service —
is the ability of our boilers to reach full output steam from a cold start in less than five minutes using the least

8
amount of energy and having the lowest environmental impact. In recognition of its compact, safe, and cost-
effective design, the high-efficiency MIURA Boiler has won numerous awards from engineering societies and
gas associations.
Features
The MIURA Steam Boiler features a once-through, forced flow, low water content, water-tube design, which
can achieve full output within five minutes. What’s more, this boiler is designed to be run with simple push-
button controls and a minimum amount of maintenance. Using the patented MIURA BL11 computer
controller, we can monitor precise characteristics of boiler operation from our offices and provide fast,
accurate feedback data. Radiant heat losses are minimal and steam quality is second to none. In addition,
MIURA Boilers are often installed in a multiple boiler network.
MIURA Boilers, in combination with the patented MIURA Multiple Installation panel, allow the required
horsepower to be brought on and off line quickly in order to meet sophisticated production needs with
maximum fuel economy. The high-efficiency MIURA Boiler has received numerous accolades in Japan,
including awards from the Japanese Society of Mechanical Engineers and the Japanese Gas Association.
This boiler is characterized by compact, safe, cost-saving performance — an advantage that is underscored
by our greater than 55% market share in the Pacific Rim region.
MIURA Boiler Co., Ltd. has developed the Low NOx Boiler using state-of-the-art technologies, and both the
flat burner and rectangular boiler vessel have been uniquely designed for the LX.
It is generally explained that the temperature of a combustion flame should be less than 3,272°F (1,800°C) in
order to prevent NOx generation. Nevertheless, combustion flames will generally have some high
temperature areas generating this harmful pollutant. Miura engineers determined the temperature distribution
in the combustion and heat exchanging areas of our boilers, and through exhaustive theoretical analysis and
rigorous testing, optimized the boiler design so as to have a uniform temperature distribution at less than
3,272°F (1,800°C). Specifically, an ideal combustion process was achieved by making the burner surface as
large as possible, and the furnace volume as small as possible. As a result, the LX and LXL boast NOx
emission levels of less than 20 PPM at 3% converted O
2
(based on natural gas combustion). Miura LX
models can also meet more stringent emission requirements (eg. NOx lower than 20ppm) upon request.
Thanks to its highly compact design, the LX fits through a standard door opening, thereby eliminating the
need to demolish doorways or knock down walls during installation.

9
The completely packaged LX features the following as standard:
•UL, c-UL approved and labeled boiler design (FM available)
•HIGH GAS and LOW GAS pressure switches
•LOW AIR pressure switch
•Control Steam Pressure transducer with a backup control pressure switch
•High steam limit pressure switch featuring a manual reset
•ASME steam safety relief valves for the boiler and an optional economizer
•Main gas line and pilot line regulators
•Dual pilot-gas solenoid valves
•Dual main-gas fluid actuator valves and plugged leak-test port (vent valve also available)
•Forced-draft blower and motor
•Completely enclosed, heavy gauge casing
•ASME stamped pressure vessel with internal inspection ports
•Two independent low-water fuel cutoffs, one featuring a manual reset
•Digital steam-pressure display with a backup pressure gauge
•Thermocouples on water tubing in order to prevent overheating due to low water or scale buildup
•Water volume control
•Intermittent Automatic Blowdown system with a strainer and manual shutoff valve
•External separator
•Blower-cover dust warning
•MIURA BL Microprocessor Boiler Control featuring a user-friendly digital display
•Communication interface functionality
•Display of hours of operation and logging of the seven most recent faults
•Support for remote modem-based monitoring of boiler performance and troubleshooting from a MIURA
technical center