as shown in table 11-4, movement of pipe can be
accounted for. In addition, piping should be sup-
ported at all changes in direction and load con-
centrations, such as heavy valves.
There are many other considerations in the
layout of compressed air systems, which are
beyond the scope of this manual. Refer to NAV-
FAC DM 3-5, Compressed Air and Vacuum
Systems, for further information.
After installation, the compressed air system
must undergo testing. Generally, all piping and
pressurized components should be tested at 150
percent of maximum working pressure. When
testing, use clean, dry air or nitrogen. The system
should be held at test pressure without loss for
at least 4 hours.
As with any system, preventive maintenance
conducted on a scheduled basis is an important
factor in providing reliable service. Breakdown
maintenance causes interruption in services that
Table 11-4.Maximum Span for Pipe