2.22
ORAL EVACUATION SYSTEM FOR DENTAL OPERATORIES
**************************************************************************
NOTE: Type of system to be used as described in
paragraphs "High-Volume Oral Evacuation System
(HVE)," "High Vacuum Oral Evacuation System
(HIVAC)," "High Volume Evacuation System (HVEL),"
and "Environmental-Janitorial Vacuum System (EJVS)"
will be determined by users; inapplicable type will
be deleted. Also, delete reference to nonused
system in Part 3. For equipment intended
specifically for installations outside of the
Continental United States (overseas bases), the
vacuum-source drive-motor frequency and voltage
requirements of this specification should be changed
to ensure compatibility with onsite electrical
supply configurations. Such modifications will not
detract from equipment longevity or performance.
**************************************************************************
2.22.1
High-Volume Oral Evacuation System (HVE)
The central HVE system shall be composed of standard manufactured products,
complete with devices normally furnished and devices required herein. The
central HVE system shall be supplied by an established manufacturer of
commercially available, industrial quality vacuum system, as a complete
system. The HVE shall be essentially a wet system, composed of two vacuum
turbines, each of which shall be sized to support the full HVE requirement.
The turbines shall be connected in parallel to the central wet separator
tanks.
2.22.1.1
Vacuum Turbines
**************************************************************************
NOTE: Vacuum turbine units should be specified for
dental operatories or clinics having six or more
chairs. For operatories and small dental clinics
having only three to five chairs, water ring type
vacuum pump may be specified.
**************************************************************************
Turbines shall be self-governing, multistage, centrifugal type, of overhung
or outboard design. The vacuum producer shall operate at a speed not to
exceed 3,600 rpm and shall be connected to its driving motor by a flexible
coupling. Bearings may be sealed or of the lubricatable type. A fan shall
be connected directly to the vacuum producer shaft adjacent to vacuum
producer shaft bearings to create a flow of ambient air over the bearing
carrier while the unit is operating. A steel coupling guard encompassing
the flexible coupling shall be installed between the motor and vacuum
producer. Cases shall be cylindrical in design. Cases and end plates
(inlet and exhaust heads included) shall be constructed of either
heavy-gauge sheet steel rigidly welded at seams and sections, or of cast
grey iron. Sheet steel end plates shall be either concave or convex.
Inlet and exhaust connections shall be tangential to the vacuum producer
except the inlet connection can be axial to vacuum producer and sized to
allow free air movement through the vacuum producer, without flow
restriction and shall have class 150 flanges. The vacuum producer input
shall have an adjustable volume control valve, a directional flow valve and
antisurge valve. The vacuum producer output shall have an exhaust
SECTION 15405A
Page 65