strictly for one type of fluid, or it may be used for several
is considerably less than from rough and
different types of fluids at separate times.
As a Hull Maintenance Technician, you will require
6. Carefully inspect, provide upkeep, and repair
some knowledge of most of the piping systems on board
heat insulation once it is installed. Replace
ship. The rest of this chapter will present some general
lagging and insulation removed to make repairs
information on the properties and characteristics of
just as carefully as when it was originally
fluids and a general description of the most common
installed. When replacing insulation, make
piping systems on board ship.
certain that the replacement material is the same
type that had been used originally.
7. Insulate all flanges with easily removable
forms. These can be made up as pads of
insulating material, wired or bound in place.
The term fluid includes liquids, gases, and vapors.
The whole can be covered with sheet metal
Fluids have no shape of their own. They will quickly
casings that are in halves and easily removed.
conform to the shape of the container they are in, and
they are easily pumped through piping systems.
The main steam, auxiliary steam, auxiliary exhaust,
feedwater, and steam heating piping systems are lagged
Both gases and vapors are gaseous substances, but
to hold in the heat. The circulating drainage, fire, and
they differ in the ease with which they can be liquified.
sanitary piping systems are lagged to prevent
If a large change in pressure or temperature is required
to liquefy a substance, it is called a gas. If a relatively
small change in pressure, or temperature, changes a
substance to a liquid, the substance is called a vapor.
Air is an example of a gas. Steam is normally
considered a vapor. When steam is superheated,
Lagging and insulation should be
however, it may be considered a gas rather than a vapor.
considered to contain asbestos unless certified
There are considerable variations in the properties
not to contain it. Do not rip out asbestos
of the liquids, gases, and vapors carried by shipboard
lagging without a respirator or stay in the area
piping systems. Some of these properties will be
of the ripout if you are unprotected. Inhaled
discussed briefly in the following paragraphs.
asbestos tiller can cause severe lung damage in
the form of disabling or fatal fibrosis of the
The property of compressibility is the main basis
lungs. Asbestos has also been found to be a
by which different liquids are distinguished from each
causal factor in the development of cancer of
other, and also by which gases are distinguished from
the membrane lining the chest and abdomen.
vapors. It is almost impossible to compress liquids, but
Lung damage and disease usually develop
gases and vapors can be compressed rather easily.
slowly and often do not become apparent until
When a force is applied to a confined liquid, the liquid
years after the initial exposure. Ripping out or
will act almost like a solid by transmitting a force
handling asbestos is restricted to the trained
equally in all directions. This example will show that
emergency asbestos removal team or an
water is not easily compressed: If a force of 15 pounds
intermediate maintenance activity (IMA).
of pressure is applied to 1 cubic inch of water, the
NSTM, chapter 635, and chapter B1 of
volume of the water will decrease only l/20,000 of what
OPNAVINST 5100.19B, NAVOSH Program
Manual for Forces Afloat, include asbestos
compression. A liquid's resistance to compression is
removal precautions and procedures.
the characteristic that allows the transmission of applied
forces in all hydraulic systems. At the same time, the
ease with which gases and vapors may be compressed
is the characteristic that makes them useful in various
compressed gas systems.
Piping systems aboard ship are used to carry steam,
The specific weight of a substance is the weight of
salt water, fresh water, fuel oil, lubricating oil, gasoline,
air, and many other fluids. All piping systems serve the
that substance per unit volume. For most shipboard
same basic purpose, to transfer fluids from one place to
another. An individual piping system may be used