Change 2, 30 December 1991
Types of Exterior Distribution Systems.
Types of exterior
distribution systems are as follows:
Steam and Condensate. These systems supply heat in the form of steam
from central steam generating plants. Several buildings, building groups, or
ship berthing facilities may be supplied with steam for domestic hot water
and/or for space heating. Heating equipment using steam includes unit
heaters, radiators, convectors, heating coils, and other devices. Process
equipment using steam includes hot water heaters, laundry machinery,
cleaning/plating tanks, kitchen equipment, and other devices. Condensate is
returned to the central plant whenever possible.
Hot Water. System circulates hot water which supplies heat from a
central heating plant to several buildings for space heating, domestic hot
water, and process work, and returns the water to the central plant. High
Temperature Water (HTW) systems operate at 260 degrees Fahrenheit (F) (127
degrees Celsius (C)) and higher; Medium Temperature Water (MTW) systems
operate between 200 degrees F (93 degrees C) to 259 degrees F (126 degrees C);
and Low Temperature Water (LTW) systems operate below 200 degrees F (93
degrees C). Material shall be selected to the same specifications as for High
Temperature Water systems, except that Military Specification (Mil. Spec.)
MIL-P-28584A, Pipe and Pipe Fittings, Glass Fiber Reinforced Plastic for
Condensate Return Lines, plastic piping may be used for LTW distribution
systems which have maximum of 125 psig at 250 degrees F (refer to para.
Compressed Air. System supplies compressed air from a compressor
plant to docks, air start systems, shops, hangars, and other structures.
Chilled Water. System circulates chilled water from a central
refrigeration plant to several buildings for space cooling and returns the
water to the central plant (refer to para. 2.2.7).
Cooling or Condensing Water. System distributes cooling water from a
central source (such as a bay, stream, or cooling tower) to several facilities
for condensing steam or refrigerants, for cooling water jackets, or stuffing
boxes. The water is then returned to the source (cooling tower) or sent to
waste in once-through systems.
System distributes natural gas or propane for gas
Naval Facilities Guide Specifications (NFGS) Related to Distribution
Systems. The following NFGSs are for use in the design of the exterior
distribution systems discussed in this handbook.