はじめに二級ボイラー技士になるためには、熱量、蒸気、燃焼に関する基礎的なことをはじめ、ボイラーの構造・自動制御・運転・燃料や関係法令など非常に幅広い知識が求められ、まったくの初心者が習得することは大変です。
一般社団法人日本ボイラ協会は、ボイラー・圧力容器を専門とする我が国唯一の学術団体です。その専門家集団が編集した本書は、まったくの初心者でも最短で確実に合格できるように、要点をわかりやすく解説したものです。
特に、重要で是非理解していただきたい項目を「ポイント」としてとりあげ、これを中心に学習していただくことにより、学習プランがたてやすく、自己チェックも容易にできるようになっています。
本書においては、過去の二級ボイラー技士免許試験で実際に出題された問題を徹底的に分析し、出題傾向や出題の頻度がわかるようにしました。
また、多数のわかりやすいオリジナルのイラストとそれに対応した理論的な解説により、ボイラーを見たことのない方でも、単なる丸暗記でなく、ボイラーを取り扱ううえで重要な事項が十分に理解できるようになっています。
本書は、2014 年に法令を除く技術科目についての図書として出版しましたが、今般新たに法令科目を追加し、全科目を網羅しました。この 1 冊で試験対策は万全です。
当協会が自信を持ってお勧めする 1 冊です。
なお、本書により独学でも十分に理解できますが、さらに理解を深めたいとお考えでしたら、当協会の支部が主催する受験準備講習会を受講されることをお勧めします。
2017 年 6 月
一般社団法人 日本ボイラ協会会長

刑部 真弘

3

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はじめに············································································································································································· 3
二級ボイラー技士免許試験の受験について······························································································ 8
本書の使い方 ····························································································································································· 10

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１. ６. ２4ボイラーの構造

ボイラーの概要··································································································································· 12ボイラーの構成 ···································································································································12ボイラーの容量及び効率 ··············································································································14ボイラーの分類 ···································································································································17丸ボイラー············································································································································· 18丸ボイラーの概要 ······························································································································18丸ボイラーの特徴 ·······························································································································18丸ボイラーの種類 ·······························································································································19
炉筒煙管ボイラー································································································································21

水管ボイラー········································································································································26
水管ボイラーの概要 ·························································································································26
自然循環式水管ボイラー ··············································································································30
強制循環式水管ボイラー ·············································································································32
貫流ボイラー ·········································································································································34

鋳鉄製ボイラー ·································································································································38
鋳鉄製ボイラーの概要 ····················································································································38
鋳鉄製ボイラーの構造 ····················································································································39
ウェットボトム形鋳鉄製ボイラー ·····························································································40
鋳鉄製ボイラーの特徴 ···················································································································41
ハートフォード式連結法 ·················································································································42
温水ボイラーの配管と膨張タンク ····························································································44

熱及び蒸気············································································································································48
基礎事項 ··················································································································································48
蒸気の性質 ············································································································································54ボイラーにおける蒸気の発生と水循環 ················································································59
伝熱·······························································································································································62

ボイラー各部の構造と強さ·········································································································66
胴及びドラム ··········································································································································66
鏡板及び管板 ·······································································································································69

１. ６. ３

炉筒及び火室（かしつ）····················································································································72

１. ６. ４

ステー ·························································································································································75

１. ６. ５穴 ··································································································································································78

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１. ６. ７

管寄せ ·······················································································································································79
管類 ·····························································································································································79

１. ６. ８溶接継手 ··················································································································································81

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附属品及び附属装置·······················································································································84
ボイラーに使用する計測器 ···········································································································84
安全装置 ··················································································································································95
送気系統装置 ···································································································································· 101
給水系統装置 ···································································································································· 111
吹出し（ブロー）装置 ·················································································································· 117
温水ボイラー及び暖房用蒸気ボイラーの附属品 ························································ 119
附属設備 ················································································································································122ボイラーの自動制御······················································································································ 132
ボイラーの自動制御の基礎 ·······································································································132
フィードバック制御 ··························································································································135
シーケンス制御 ·································································································································140
各部の制御 ········································································································································· 141２
２. １
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２. ２. １２. ２. ２２. ２. ３２. ２. ４ボイラーの取扱い

ボイラーの運転操作····················································································································· 158
ボイラー取扱いの基本事項 ·····································································································158
使用開始前の準備 ··························································································································158
点火前の点検、準備 ·····················································································································158
点火 ························································································································································· 162
圧力上昇時の取扱い ····················································································································168
ボイラー運転中の取扱い ··········································································································· 172
運転中の障害とその対策 ···········································································································180
使用停止時の取扱い ····················································································································194
石炭だきボイラーにおける燃焼 ·····························································································196

附属品及び附属装置の取扱い······························································································· 198
圧力計（水高計）·······························································································································198
水面測定装置 ·····································································································································199
安全弁、逃がし弁及び逃がし管 ····························································································206
吹出し装置 ·········································································································································· 213
5

２. ２. ５給水装置 ··············································································································································· 217

２. ２. ６自動制御装置 ·····································································································································221

２. ３ボイラーの保全································································································································ 224

２. ３. １ボイラーの保全一般 ·····················································································································224

２. ３. ２ボイラーの清掃 ································································································································224

２. ３. ３２. ３. ４２. ３. ５

新設または修繕後のボイラー使用前の措置 ··································································235
ボイラーの休止中の保存法 ······································································································235
ボイラーの検査 ································································································································239

２. ４
２. ４. １
２. ４. ２２. ４. ３２. ４. ４２. ４. ５２. ４. ６ボイラーの水管理·························································································································· 244
ボイラー用水 ·······································································································································244
水の一般的性質 ·······························································································································244
水に関する用語と単位 ··················································································································244
水中の不純物による障害 ···········································································································248
補給水処理 ··········································································································································251
ボイラー系統内処理 ·····················································································································256

３ 燃料及び燃焼
３. １
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３. １. ３３. １. ４３. １. ５

３. ２
３. ２. １３. ２. ２３. ２. ３３. ２. ４
３. ２. ５３. ３
３. ３. １
３. ３. ２6燃料························································································································································· 266
燃料概論 ···············································································································································266
液体燃料 ···············································································································································271
気体燃料 ···············································································································································280
固体燃料 ···············································································································································283
特殊燃料 ··············································································································································287

燃焼方式と燃焼装置···················································································································· 289
燃焼の要件 ·········································································································································289
液体燃料の燃焼方式 ····················································································································292
気体燃料の燃焼方式 ···················································································································· 310
固体燃料の燃焼方式 ··················································································································· 316
大気汚染の防止 ································································································································321

燃焼室及び通風······························································································································ 328
燃焼室 ····················································································································································328
通風 ·························································································································································337

４ 関係法令
４. １

ボイラーの定義、用語等·········································································································· 350

４. １. １ボイラーの定義 ································································································································350

４. １. ２最高使用圧力の定義 ·····················································································································351

４. １. ３

伝熱面積の定義·································································································································351

４. ２
４. ２. １４. ２. ２４. ２. ３４. ２. ４

製造から廃止までの届出、検査等···················································································· 356
製造等 ····················································································································································357
設置 ·························································································································································358
性能検査 ···············································································································································360
変更、休止及び廃止 ·····················································································································362

４. ３ボイラー室··········································································································································· 368

４. ４ボイラーの取扱い・管理··········································································································· 373

４. ４. １
４. ４. ２４. ４. ３４. ４. ４４. ４. ５４. ４. ６

４. ５
４. ５. １
４. ５. ２４. ５. ３４. ５. ４４. ５. ５４. ５. ６４. ５. ７ボイラー取扱の就業制限 ············································································································373
ボイラー取扱作業主任者 ··········································································································· 374
ボイラー取扱作業主任者の職務 ···························································································376
附属品の管理 ····································································································································377
定期自主検査 ····································································································································378
整備等の作業 ····································································································································379

ボイラー構造規格（抜粋）········································································································ 384
鋼製ボイラーの安全弁、逃がし弁及び逃がし管 ·······················································384
鋼製ボイラーの圧力計、水高計及び温度計 ··································································386
鋼製ボイラーの水面測定装置 ·································································································387
鋼製ボイラーの給水装置等 ·····································································································389
鋼製ボイラーの蒸気止め弁、吹出し装置、爆発戸 ·················································390
鋼製ボイラーの自動制御装置 ·································································································391
鋳鉄製ボイラー ·································································································································393

索引·················································································································································································· 3987

二級ボイラー技士免許試験の受験について
１．受験資格平成 24 年 4 月 1 日から、二級ボイラー技士免許試験の受験資格はなくなり、国籍、性別、職業、年齢などに関係なく、誰でも受験できます。ただし、免許申請の際は、免許交付要件としてボイラー実技講習修了か実務経験が必要となりますので、ご注意ください。
実務経験がない方は、都道府県労働局長の登録を受けた当協会各支部が実施するボイラー実技講習を修了することにより、免許交付要件となります。ボイラー実技講習
は、免許試験の受験前でも免許試験に合格した後でも受講することができます。
２．免許試験の実施と試験範囲

二級ボイラー技士免許試験は、厚生労働大臣が指定した試験機関である公益財団法人安全衛生技術試験協会が、試験場となる各地の安全衛生技術センターにおいて毎月 1 〜 2 回実施しています。これ以外に年数回、出張特別試験も実施しています。
二級ボイラー技士免許試験の試験科目と配点、試験時間、試験範囲は表のとおりです。また、解答は 5 つの選択肢から 1 つを選ぶマークシート方式です。
試験科目

出題数（配点）ボイラーの構造に関する知識10 問（100 点）

ボイラーの取扱いに関する知識10 問（100 点）

燃料および燃焼に関する知識10 問（100 点）

関係法令

10 問（100 点）

試験科目

試験時間

3 時間

試験範囲

ボイラーの構造に関する知識

熱及び蒸気、種類及び型式、主要部分の構造、附属設備及び附属品の構造、自動制御装置

ボイラーの取扱いに関する知識

点火、使用中の留意事項、埋火、附属装置及び附属品の取扱
い、ボイラー用水及びその処理、吹出し、清浄作業、点検

燃料及び燃焼に関する知識
関係法令

燃料の種類、燃焼方式、通風及び通風装置
労働安全衛生法、労働安全衛生法施行令及び労働安全衛生
規則中の関係条項、ボイラー及び圧力容器安全規則、ボイラー構造規格中の附属設備及び附属品に関する条項

３．受験申請手続

受験申請書は、公益財団法人安全衛生技術試験協会本部、または各地の安全衛8

生技術センター、当協会各支部において無料で配布しています。
受験の申込みは、受験申請書と本人確認証明書等の必要書類、証明写真、試験手数料とともに、受験を希望する安全衛生技術センターに、簡易書留郵便により郵送するかまたは直接提出してください。
受験申請には申請書のほかに、本人確認証明書（氏名、生年月日及び住所を確認できる書類）として、以下の書類のいずれか一つを添付することが必要です。
① 住民票記載事項証明書又は住民票（写 不可）② 健康保険被保険者証の写（表裏）③ 労働安全衛生法関係各種免許証の写（表裏）④ 自動車運転免許証の写（表裏）⑤ その他氏名、生年月日及び住所が記載されている身分証明書等の写※この本人確認証明書に限り、写しには「原本と相違ないことを証明する」との事
業者等の証明は不要です。
申請期間は、受験を希望する試験日の 2 ヶ月前からとなっており、締切については郵送の場合は試験日の 14 日前の消印があるものまで有効となっています。直接各センターの窓口に提出する場合は、試験日の 2 日前の16 時まで（例：試験日が月曜日の場合、2 日前は前週の木曜日になる）となっています。
いずれも、第 1 希望日の定員に達した場合には、第 2 希望日になりますので、早めに手続きをしてください。
詳細については、各センター及び公益財団法人安全衛生技術試験協会本部（「5. 免許試験に関する問い合わせ」を参照）までお問い合わせください。
４．合格基準二級ボイラー技士免許試験の合格基準は、試験科目ごとの得点が 100 点満点の40％以上であって、かつ、4 科目の合計点が 60％以上の場合が合格になります。
５．免許試験に関する問い合わせ
問い合わせ先

電話番号

問い合わせ先

電話番号

公益財団法人安全衛生技術試験協会 03-5275-1088 中部安全衛生技術センター 0562-33-1161
北海道安全衛生技術センター

0123-34-1171 近畿安全衛生技術センター 079-438-8481

東北安全衛生技術センター

0223-23-3181 中国四国安全衛生技術センター 084-954-4661

関東安全衛生技術センター

0436-75-1141 九州安全衛生技術センター 0942-43-3381

9本書の使い方
本書は、「構造」「取扱い」「燃料及び燃焼」「関係法令」の各科目について、公益財団法人安全衛生技術試験協会が実施する、二級ボイラー技士免許試験で出題された公表問題を徹底研究し、合格に直結する重要項目を「ポイント」として整理した「重点ポイント方式」としています。

１．
「ポイント」では：① 「ポイント」中心に学習を進めてください。
「ポイント」とその解説でボイラーを取扱ううえで重要なことがほとんど理解できるようになります。
② 過去に公表された二級ボイラー技士免許試験問題を網羅して「ポイント」が作られていますので、これを読んでいただくことで、同時に二級ボイラー技士免許試験の出題問題も解けるようになります。
③ 「構造」「取扱い」「燃料及び燃焼」については、すでに受験生が理解している項目と理解できない項目を、受験生自身が「自己診断」できるシステムを採用しています。
「ポイント」の文章だけで理解できる場合には、そのあとに続く解説を読まずに次に進んでいただいてもよいと思います。このとき、□欄（Skip □）に○マークを入れます。すでに理解している「ポイント」の解説をスキップすることで、より短期間に合格圏に到達することができます。

２．
「公表問題を解いてみよう」では：① 「ポイント」を理解してから、「公表問題を解いてみよう」に進みましょう。解答できなかった、あるいは誤って解答してしまった場合は、選択肢のそれぞれ末尾に付いた「ポイント」に戻って、もう一度復習しましょう。そうすれば、確実に理解が進みます。
（公表問題では、類似の問題を避けるため、一部修正しているものがあります。
）② ☆印（ 出題率 ）の数により出題傾向・頻度を表しています。		 ☆☆☆：最頻出

☆☆：頻出

☆：普通

③ より自信をつけたい方向けに、当協会では「2 級ボイラー技士試験公表問題解答解説」、「2 級ボイラー技士試験標準問題集」を発行しています。数多くの問題を解くことで着実に理解度がアップします。		（巻末の受験関係図書籍参照）

10