COMPRESSED GASES AND
VACUUM SYSTEMS FOR
Michael Frankel, CIPE
Utility Systems Consultants, Somerset, New Jersey
This chapter will describe piping for vacuum, compressed air, and specialty com-
pressed gas systems typically found in general, teaching, chemical, pharmaceutical,
biological, and physics laboratories.
Compressed gases used in laboratories are characterized by low delivery pressure,
low to intermittently high volume, and high purity requirements of the gas and of
the piping distribution system. The usual working pressure is in the range of 50 to
55 psig (345 to 380 kPa). The primary source of pure gases is from cylinders, since
it is extremely rare that the quantity of pure gases used for laboratory and research
purposes would justify large bulk storage.
Principal uses of vacuum are drying, filtering, fluid transfer, and evacuating air
from apparatus. The usual working pressure of vacuum systems is in the range of
15 to 20 in Hg vacuum (50 to 35 kPa abs). In some cases, there is a local need for
‘‘high’’ vacuum in the range of 24.0 to 29.6 in Hg vacuum (20 to 0.1 kPa abs), which
is usually produced with a separate vacuum pump.
CODES AND STANDARDS
There are no building codes directly regulating the installation of these systems.
The building codes impacting the installation of various laboratory vacuum and gas
systems are concerned with safety and health of operating personnel and building
occupants, and requirements concerning fire and structural consequences of acci-
dents. Standards—which are generally consensus standards published by interested
organizations—are concerned with the purity of a gas for specific uses and standard
dimensions of pipe, fittings, and connectors. There are no mandated code sizing re-
Compressed Gas Association (CGA)
Minimum purity requirements for various gases are addressed in CGA publications
called Commodity Standards, which also contain material, pressure, and dimensional
standards for pipe connecti