Locomotive boiler sectioned - Drawing. Public domain image.

Locomotive boiler, sectioned view
Diagram showing construction of a locomotive boiler. Also cross sections of round-topped, Belpaire and Wootten fireboxes.
Note that this boiler is not superheated.

Key

AP
Ash Pan

B1
Boiler Barrel (1st ring)

B2
Boiler Barrel (2nd ring)

B3
Boiler Barrel (3rd ring)

BA
Brick Arch

BD
Back Damper

BL
Blower

BP
Blast Pipe

BPL
Back Plate

BTP
Back Tube Plate

C
Chimney

CS
Crown Sheet

DP
Deflector Plate

FB
Firebox (inner)

FD
Front Damper

FH
Fire Hole

FR
Foundation Ring

FTP
Front Tube Plate

GB
Grate Bars

OFB
Outside Firebox

PP
Petticoat Pipe

R
Regulator

RH
Regulator Handle

RS
Regulator Spindle

S
Stays

SB
Smokebox

SD
Steam Dome

SMD
Smokebox Door

SP
Steam Pipe

SS
Sling Stays

ST
Screw Stays

SV
Safety Valves

T
Tubes

TP
Throat Plate

WL
Water Level