Upon completing this chapter, you should be able to do the
1. Identify the different types of liquid-cooling systems for
electronic fire-control equipment.
2. Identify the components for the liquid-cooling systems.
3. Identify the maintenance responsibilities for the liquid-
cooling systems used by Fire Controlmen.
Cooling systems are essential to the satisfactory
operation of a shipboard weapons system. In fact,
some form of cooling is required for all shipboard
electronic equipment, and liquid cooling is especially
efficient for the transfer of large amounts of heat. To
maintain cooling systems, you must have a broad
understanding of the different types of liquid-cooling
systems with which you are involved. As a Fire Con-
trolman, and because you operate and maintain elec-
trical and electronic equipment, you are required to
have a thorough knowledge of liquid-cooling systems.
This chapter discusses basic liquid-cooling
systems, liquid-cooling systems configurations, and
liquid-cooling systems for the Mk 92 fire-control
system (FCS). It also discusses the maintenance re-
sponsibilities you have as a Fire Controlman for these
systems. For more detailed information on these and
other cooling systems, consult your applicable oper-
ating procedures and Basic Liquid Cooling Systems
for Shipboard Electronics, NAVSEA 0948-LP-122-
BASIC LIQUID-COOLING SYSTEMS
The typical liquid-cooling system is composed of
two basic cooling systems: primary and secondary.
These two systems are discussed briefly in this sec-
PRIMARY LIQUID-COOLING SYSTEM
The primary liquid-cooling system provides the
initial source of cooling water that can be either sea-
water or chilled water from the ships air-conditioning
plant, or a combination of both. Figures 2-1, 2-2, and
2-3 show the basic arrangement of liquid-cooling
systems that use seawater and chilled water. You are
encouraged to refer to these three figures as you study
In figure 2-1, seawater from a sea connection is
pumped by a seawater circulating pump in one of the
ships engineering spaces through a duplex strainer to
remove all debris and then is pumped through the
tubes of a heat exchanger. Finally, the seawater is dis-
charged back into the sea at an overboard discharge.