MIL-HDBK-1191
9.6.15.3
Performance. A minimum vacuum of 51 kPa (15 in-Hg) shall be
maintained at the receiver. The operating range shall be 51 to 65 kPa
(15 to 19 in-Hg). A minimum vacuum of 41 kPa (12 in-Hg) shall be
maintained at the farthest inlet. System pressure drop shall be a
maximum of 10 kPa (3 in-Hg) at the calculated demand flow rate. A flow
rate of 1.4 L/s (3 scfm) per inlet, with no equipment attached, shall be
measured while maintaining 41 kPa (12 in-Hg) vacuum at the farthest
inlet. The 1.4 L/s (3 scfm) without equipment is equivalent to the
recommended 0.7 L/s (1.5 scfm) with.
Slide Brackets. Vacuum bottle slide brackets shall be
9.6.15.4
provided for all medical vacuum inlets. Vacuum bottles shall be used at
all vacuum inlets to prevent liquids and solids from entering the piping
network. Vacuum bottles shall be provided with an overflow shut-off
device to prevent carry over of fluids or solids into the piping system.
Brackets shall be positioned to provide proper clearance for flow meters
and adapters and to eliminate conflict with electrical receptacles.
Thus, it is recommended that the vacuum outlet be located at either end
of a group of medical gas outlets, with the slide bracket to the outside,
e.g. in a healthcare station head wall unit. If two vacuum inlets are
required at a given station, locate one at each end of the outlet group
with the slide brackets to the outside. It is critical to coordinate
vacuum inlet and slide locations with the Architectural Designer and the
User's representative to avoid interference with other items without
compromising the medical function.
Vacuum shall be exhausted in accordance with NFPA
9.6.15.5
99 (reference 9r).
Dental High Vacuum (DHV). A central DHV system may be
9.6.16
supplied for areas in dental clinics where MV is required as specified in
Appendix "A." This system is also a dry system with a central piped
distribution system and receiver; no liquids or solids shall be
transported in the distribution system. Individual separators shall be
located in each applicable DTR. The system shall consist of two or more
vacuum pumps and a central receiver. System shall be sized so that upon
failure of one pump the remaining pump(s) shall maintain the minimum
vacuum specified while providing 100% of the calculated demand. The
system design shall include automatic operation of the vacuum pumps
including alternating lead/lag status. Provide an alarm to indicate
vacuum pump failure that annunciates to the master medical gas alarm
panel. For dental clinics located in a hospital, the MV system may be
used in lieu of a DHV system.
Performance. A minimum vacuum of 65 kPa (19 in-Hg) shall be
9.6.16.1
maintained at the receiver. System pressure drop shall be such that the
most remote inlet will have a minimum vacuum of 41 kPa (12 in-Hg) under
peak demand conditions.
Demand. System demand shall be calculated based on 0.9 L/s
9.6.16.2
(2 SCFM) for each DTR DHV inlet with the demand factors in Table 9-9:
TABLE 9-9
DHV DEMAND FACTORS
Use Factor
No. of DTR DHV Inlets
1- 6
1.0
7 - 10
0.8
Over 10
0.6
9-24
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