This is the drawing we use when hooking up a steam system.  We start with the complete diagram and then highlight the portions to be used, as not all installations are the same.  So we do not imply that all the components and valves are needed for all installations.  However there must be a good and logical reason to omit any items from your steam installation.

Types of Valves used and Code  in diagram:

         B       Ball with SS ball, teflon packing
         P        Petcock
        Q        Quick acting or whistle
        N        Needle
        C        Check
        S         Safety, relief

Valve Selection

Code     Size     Type     Purpose:
  1          1/2         B       Main Steam valve
  2          1/2         B       Throttle
  3          1/2         B       Whistle supply
  4          1/4         Q       Whistle
  5          3/8         B        Boiler pressure gage
  6          1/2         B        Boiler water fill
  7          1/2         B        Injector steam
  8          1/2         B        Injector water
  9          1/2         B        Injector boiler FW
  A         1/4         B        Stack blower
  B         1/2         B        Feed water to boiler
  C         1/2         S        Feed water safety/relief
  D         1/2         B        FW Exhaust heater
  E          1/2         B        Feed water routing
  F          1/2         B        Feed water to boiler
  G         1/2         B        Hand FW pump supply
  H         3/8         B        FW Auto float by-pass
  I           3/8         B        FW Manual by-pass
  J          1/2         B        Make up tank (water)
  K         1/4         P        Cyl./steam chest drains
  L           1           B        Condenser Input
  M        1/4         B        Condenser Output
  N         3/4         B        Blowdown
  O         3/4         B        Seacock blowdown
  P         1/2          B        Ejector steam
  Q         1/2         B        Ejector steam
  R         1/2         B        Sight gage
  S         1/2         B        Try cocks
  T         1/4         P        Gage clock protectors
  U         1/4         P        Dampener drain/bleed
  V         1/2         B       Boiler pre-heater
  W        1/2         B       Boiler super heater
  X         1/2         C       FW check
  Y         1/4         B        Lubricator
  Z          3/4         S       Boiler pressure safety

It is rather a toss-up whether to begin with the main steam line or with feed water to the boiler.  Probably the latter is the more important as on needs to have safe and secure means of getting water into the boiler at all times.  There should be at least two ways of getting water into the boiler when it is under pressure.
Here we show a feed water pump operating directly from the engine.  This may be a reciprocating piston or geared pump.  As the latter is frequently unreliable, a better selection is a double acting twin piston pump chain driven from the engine  or propeller shaft.  As the feed water pump requires the engine to be turning, it is useful to have a steam injector which can be operated at any time there is steam up.  The secret to successful injector operation is to provide it with cool, clean water having a positive head, that is, downhill from the freshwater tank.  Steam is provided via (7), water via (8), and the steam then delivers the water into the boiler at (9), through check valves (X).
As backup, a hand feed water pump of a large capacity displacement with a long handle is essential.  Far too many hand pumps installed require thousands of strokes to get a gallon of water into the boiler when urgently needed.  Water to the hand feed water pump is controlled by (G).
Some installations may have other pressure pump selections such as steam driven simplex, duplex water pumps, or electrically driven piston pumps.  But, whatever the choices,  being  able to introduce
water under pressure to the boiler is mandatory!!
Boiler water level is ascertained by observing the sight gage or by opening one of the trycocks placed in the system.  One should follow without exception the rule that when water is not clearly visible in the sight gage, emergency procedures to add water to the boiler and to extinguish the fire should be followed without delay! Don't make the assumption that  the water level  is just below the sight glass.  If you don't see  water in sight glass, put fire out or overboard. Close draft door, open firebox door. Add water.

GO TO S/B 101 Intro.Index Page

Next: Continuing System Description