Piping Requirements; Electrical Requirements - Xylem LOWARA ESHS ATEX Manual De Instalación, Uso Y Manutención

Pump position and clearance
Provide adequate light and clearance around the
pump. Make sure that it is easily accessible for
installation and maintenance operations.
Installation above liquid source (suction lift)
The theoretical maximum suction height of any pump
is 10.33 m. In practice, the following affect the
suction capacity of the pump:
•
Temperature of pumped liquid
•
Elevation above the sea level (in an open
system)
•
System pressure (in a closed system)
•
Resistance of the pipes
•
Own intrinsic flow resistance of the pump
•
Height differences
The following equation is used to calculate the
maximum height above the liquid level which the
pump can be installed:
*10.2 - Z) ≥ NPSH + H
(p
b
p Barometric pressure
b
pressure).
NPSH Value in meter of the pump intrinsic flow
resistance.
H Total losses in meters caused by passage
f
of liquid in the suction pipe of the pump.
H Steam pressure in meters that correspond
v
to the temperature of the liquid T °C.
0.5 Recommended safety margin (m).
Z Maximum height at which the pump can be
installed (m).
NOTICE:
•
Do not exceed the pumps suction
capacity as this could cause cavitation
and damage the pump.
•
It is forbidden to operate with the delivery
closed for more than a few seconds. If
this is inevitable, a bypass circuit must be
installed to prevent overheating of the
liquid inside the pump.
4.2.2

Piping requirements

Precautions
WARNING:
•
Use
maximum working pressure of
the pump. Failure to do so can
cause the system to rupture,
with the risk of injury.
•
Have
made by qualified installers in
compliance
regulations in force.
NOTICE:
Observe all regulations issued by authorities
having jurisdiction and by companies managing
+ H + 0.5
f v
in bar (system
pipes suited to the
all the connections
with the
the public water supplies if the pump is
connected to a public water system. If required,
install appropriate backflow-prevention device on
the suction side.
Piping checklist
Check that the following requirements are met:
•
All piping is independently supported, piping
must not place a burden on the unit.
•
Flexible pipes or unions are used, in order to
avoid transmission of pump vibrations to the
pipes and vice versa.
•
Use wide bends, avoid using elbows which
cause excessive flow resistance.
•
The suction piping is perfectly sealed and
airtight.
•
If the pump is used in an open circuit, then the
diameter of the suction pipe is suited to the
installation conditions. The suction pipe must
not be smaller than the diameter of the suction
port.
•
If the suction piping must have a diameter larger
than the suction side of the pump, an eccentric
pipe reducer must be installed.
•
If the pump is placed above liquid level, a foot
valve is installed at the end of the suction
piping.
•
The foot valve is fully immersed into the liquid
so that air cannot enter through the suction
vortex, when the liquid is at the minimum level
and the pump is installed above the liquid
source.
•
Appropriately sized on-off valves are installed
on the suction piping and on the delivery piping
(downstream to the check valve) for regulation
of the pump capacity, for pump inspection, and
for maintenance.
•
Appropriately sized on-off valve is installed on
the delivery piping (downstream to the check
valve) for regulation of the pump capacity, for
pump inspection, and for maintenance.
•
In order to prevent back flow into the pump
when pump is turned off a check valve is
installed on the delivery piping.
WARNING:
Do not use the on-off valve on the
discharge side in the closed position in
order to throttle the pump for more
than a few seconds. If the pump must
operate with the discharge side closed
for more than a few seconds, a
bypass circuit must be installed to
prevent overheating of the liquid inside
the pump.
For illustrations that show the piping requirements,
see Figure 8 on page 91 and Figure 9 on page 91.
4.2.3

Electrical requirements

•
The local regulations in force overrule these
specified requirements.
en – Original instructions
21