|  | F |
SECTION F — MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

|  | F01 - F04 |
Subsection index
MACHINES |
positive displacement |
rotary or oscillating piston |
liquid and elastic fluid or elastic fluid | F01C
liquid only | F04C
reciprocating piston or other |
liquid and elastic fluid or elastic fluid | F01B
liquid only | F04B
non-positive displacement |
liquid and elastic fluid or elastic fluid | F01D
liquid only | F03B
ENGINES |
positive displacement |
rotary or oscillating piston |
liquid and elastic fluid or elastic fluid | F01C
liquid only | F03C
reciprocating piston or other |
liquid and elastic fluid or elastic fluid | F01B
liquid only | F03C
non-positive displacement |
liquid and elastic fluid or elastic fluid | F01D
liquid only | F03B
PUMPS |
positive displacement |
rotary or oscillating piston | F04C
reciprocating piston or other | F04B
non-positive displacement | F04D

LIGHTING; HEATING

|  | F22 |
STEAM GENERATION (chemical or physical apparatus for generating gases Fulltext... Hierarchy... Expanded...B01J; chemical generation of gas, e.g. under pressure, Section C; removal of combustion products or residues, e.g. cleaning of the combustion contaminated surfaces of tubes of boilers, Fulltext... Hierarchy... Expanded...F23J; generating combustion products of high pressure or high velocity Fulltext... Hierarchy... Expanded...F23R; water heaters not for steam generation Fulltext... Hierarchy... Expanded...F24H, Fulltext... Hierarchy... Expanded...F28; cleaning of internal or external surfaces of heat-transfer conduits, e.g. water tubes of boilers, Fulltext... Hierarchy... Expanded...F28G)

|  | F22 |
Note(s) In this class, the following term is used with the meaning indicated: "steam" covers also other condensable vapours, e.g. mercury, diphenyl, diphenyl oxide.

|  | F22B |
METHODS OF STEAM GENERATION; STEAM BOILERS (steam engine plants where engine aspects predominate Fulltext... Hierarchy... Expanded...F01K; domestic central-heating systems using steam Fulltext... Hierarchy... Expanded...F24D; heat exchange or heat transfer in general Fulltext... Hierarchy... Expanded...F28; generation of vapour in the cores of nuclear reactors Fulltext... Hierarchy... Expanded...G21)

|  | F22B |
Note(s) This subclass covers only methods of, or apparatus for, the generation of steam under pressure for heating or power purposes.

|  | F22B |
Subclass index
METHODS FOR STEAM GENERATION | 1/00, 3/00
STEAM BOILERS |
General characteristics |
having drum; having furnace tube; having fire tube; having combined fire tube and water tube; having fire-box | 5/00; 7/00; 9/00; 11/00; 13/00
having water tubes |
auxiliary tubes | 11/00
horizontal; horizontally-inclined; combined horizontally-inclined and vertical; vertical or steeply-inclined | 15/00; 17/00; 19/00; 21/00
formed of sets of spaced double-walled water tubes or of return tubes; water tubes with internally-arranged flue tubes | 23/00; 25/00
Special characteristics | 27/00, 29/00
Modifications or arrangements; details of general application | 31/00; 37/00
PLANTS; CONTROL SYSTEMS | 33/00; 35/00

|  | F22D |
PREHEATING, OR ACCUMULATING PREHEATED, FEED-WATER; FEED-WATER SUPPLY; CONTROLLING WATER LEVEL; AUXILIARY DEVICES FOR PROMOTING WATER CIRCULATION WITHIN BOILERS (chemical treatment of water, e.g. purification, Fulltext... Hierarchy... Expanded...C02F; enclosed heat-exchange apparatus in general Fulltext... Hierarchy... Expanded...F28D; controlling in general Fulltext... Hierarchy... Expanded...G05)

|  | F22G |
SUPERHEATING OF STEAM (steam-separating arrangements in boilers Fulltext... Hierarchy... Expanded...F22B 37/00)