1. Except as
otherwise justified by an engineer and approved by the Division or the
appropriate district board of health, a supplier of water shall ensure that,
with regard to the suction piping of the public water system:
(a) The velocity of water in the piping is in
compliance with the specifications and recommendations of the manufacturer of
the pump and Standard
9.6.6 of the American National
Standards Institute and Hydraulic Institute, as adopted by reference in NAC
445A.6663.
(b) The diameter of the piping is sized in
compliance with the specifications and recommendations of the manufacturer of
the pump and Standard
9.6.6 of the American National
Standards Institute and Hydraulic Institute, as adopted by reference in NAC
445A.6663.
(c) The reducer between the piping and the
pump is an eccentric reducer and not a concentric reducer.
(d) A fitting is installed between the inlet
valve and pump which will allow easy removal of the pump. For pumps in suction
lift, unions must not be used, and valves, except for foot valves, must not be
installed on suction lines.
(e)
There is a continuous slope up from the surface of the water to the pump. The
suction line must be as straight as possible, and the restriction of suction
must be minimized.
(f) If there is
a valve on the suction line, except as otherwise provided in subsection 2,
there is installed between the valve and the pump, preferably on a spool, a
permanent pressure gauge that:
(1) Operates
within the appropriate range of pressure; and
(2) Is equipped with a pet cock or ball
valve. Except when the gauge is being read, the pet cock and ball valve must
remain closed.
(g) If
elbows are required in the suction line, the elbows are designed in compliance
with the specifications and recommendations of the manufacturer of the pump and
Standard 9.6.6 of the American National
Standards Institute and Hydraulic Institute, as adopted by reference in NAC
445A.6663.
(h) Each inlet of a suction pipe in a suction
well or clear well is:
(1) Bell-shaped in such
a manner as to reduce head loss at the entrance. Square-cut inlets are
prohibited.
(2) Adequately
submerged, in accordance with the specifications of the manufacturer, at a
depth of at least six times the diameter of the pipe.
(3) Located away from:
(I) The floor of the suction well or clear
well at a distance specified by the manufacturer of the pump or, in the absence
of such a specification, at a distance of not less than four nor more than five
times the diameter of the pipe.
(II) The sidewall of the suction well or
clear well at a distance specified by the manufacturer of the pump or, in the
absence of such a specification, at a distance of not less than one-half the
diameter of the pipe nor more than the diameter of the pipe.
(i) If an inlet screen
is installed:
(1) The inlet screen is
designed in such a manner that an adequate flow can enter the pump when half of
the screen is plugged.
(2) The
diameter of the screen inlet is at least three times the diameter of the
suction pipe inlet.
(j)
If a foot valve is used, the diameter of the foot valve is at least 2 inches
greater than that of the inlet piping.
(k) If a pump is connected to a header used
for suction:
(1) The connection is at an angle
relative to the header of not less than 30 degrees nor more than 45 degrees;
or
(2) If it is necessary to
connect the pump to the header at an angle of 90 degrees, the pump is located
away from the header at a distance in compliance with the specifications and
recommendations of the manufacturer of the pump and Standard
9.6.6 of the American National
Standards Institute and Hydraulic Institute, as adopted by reference in NAC
445A.6663.
(l) If a pump is in suction head, a valve is
installed in the suction line to facilitate the removal of the pump for
maintenance. The valve must not be used to throttle the pump.
2. In lieu of installing a
permanent pressure gauge as required by paragraph (f) of subsection 1, a
supplier of water may install a connection for a temporary pressure gauge and a
pressure transducer with a local or remote indicator. A temporary pressure
gauge installed pursuant to this subsection must be maintained
on-site.
Added to NAC by Bd. of
Health, eff. 2-20-97; A by Environmental Comm'n by R194-08, 10-27-2009; A by
R104-22A,
eff. 12/9/2022