- A nitrogen purge blow down of piping shall be required
before connection of the gas or vacuum outlet/inlet in accordance
with NFPA 99.
- The EN 737 "Test for Particulate Testing of the Pipeline"
shall be modified to meet the more rigid testing requirements of the
"Piping Particulate Test" of NFPA 99.
- Two master alarm panels shall be provided for each
Additional alarm features required by NFPA 99, but not
by EN 737, shall be provided for master, local area, and source
equipment alarms panels.
- Medical gas zone valves shall be in accordance with EN
737, of the ball type.
Pressure gauges shall be provided on the
pipelines at the valve box locations.
The medical vacuum line
shall include a shutoff valve similarly as the other gas services.
- Two vacuum producers, each sized for 100% of demand,
shall be provided for the Waste Anesthesia Gas Evacuation (WAGE)
Seismic Requirements. Seismic design criteria are provided
in the Seismic Design Section 6 of this document.
Corrosion Protection. All piping which will be installed in
an environment that supports galvanic reaction shall be protected from
corrosion in accordance with Military Department criteria and the
standards and recommended practices of the National Association of
Corrosion Engineers (reference 9c).
Waterborne Pathogen Prevention/Control. The Center for
Disease Control (CDC) (reference 9d), the American Society of Heating,
Refrigeration, and Air-Conditioning Engineers (ASHRAE) (reference 9e),
the American Society for Healthcare Engineering (ASHE) and the Joint
Commission on Accreditation of Healthcare Organizations (JCAHO)
(reference 9f) have cited two main means by which waterborne pathogens
are introduced into MTF's - by the water supply system and cooling
towers. Water-borne bacteria, chiefly Legionella, have been documented
as the infectious pathogens in a significant percentage of nosocomial
infections. The diseases associated with legionella infection are
legionellosis, frequently resulting in pneumonia, and Pontiac Fever, a
less severe illness. The guidance provided in this Section addresses
control of Legionella in plumbing systems, and is based in principle on
the recommendations found in these references. Typical water supply
systems, including base or public central distribution and local wells,
must be presumed to be contaminated with the Legionella bacteria.
Standard water utility treatment and testing practices are not considered
adequate to ensure protection against the bacteria entering a facility.
It is therefore necessary that Legionella bacteria prevention and control
guidelines be considered in MTF designs.
Legionella Characteristics and Transmission. The legionella
bacterium is found throughout earth and water (aquifers, wells,
reservoirs) environments, and must be expected in all water supplies.
The greatest danger to humans occurs when the organism is permitted to
multiply or "amplify" in a water supply system to the point that
significant numbers of bacteria are present. Factors that lead to
amplification include the following: