Publicidad
Idiomas disponibles
Idiomas disponibles
Installation, use and maintenance
12.2 NOTES ON SUCTION AND DELIVERY LINES
DELIVERY
EFFECTS ON
Length and diameter of pipe, flow rate of dispensed liquid, accessories fitted, can create back
pressures above those allowed.
FLOW RATE
In this case, the pump mechanical control (bypass) will trip to reduce the flow rate.
HOW TO
To avoid these problems, system flow resistances must be reduced using shorter and/or larger
diameter pipes, as well as line accessories with low resistances (e.g., automatic nozzle for higher
REDUCE
flow rates).
EFFECTS ON
FLOW RATE
CHARACTER-
ISTICS OF
DELIVERY
PIPES
SUCTION
FOREWORD
Diaphragm positive-displacement pumps are self-priming and feature good suction capacity.
During the start-up phase, when the suction pipe is empty and the pump is wet, the electric pump
unit is able to suck liquid from a maximum vertical distance of 2 mt.
IMPORTANT
NOTE
WARNING
CAVITATION
The pump is able to work with vacuums of up to 0.5 bar at the suction mouth. Over this value,
CAVITATION can occur that causes a fall in flow rate and increase in noise levels.
HOW TO
It is important to ensure low vacuums at suction mouth by using:
- short pipes with larger or identical diameter to that recommended
PREVENT
- reduce bends to the utmost
CAVITATION
- use large-section suction filters
- use foot valves with minimum possible resistance
- keep the suction filters clean because, when they become clogged, they increase the resistance
of the system.
WARNING
ATTENTION
ATTENTION
CHARACTER-
ISTICS OF
THE SUCTION
PIPES
10 /48
The delivery pipe must have the following technical characteristics:
- recommended minimum nominal diameter: 3/4"
- recommended nominal pressure: 10 bar
Priming time can last a few minutes. We suggest performing priming operations
without automatic nozzle and making sure the pump is properly wet.
Always install a foot valve to prevent the suction pipe from being emptied and to
keep the pump wet at all times. In this way, the pump will always start up immediately
the next times it is used.
The vertical distance between the pump and the fluid must fall within the 2 mt. maximum
required for priming. If the distance is greater, a foot valve must be installed to allow the
suction pipes to fill up and the diameter pipes must be larger. It is recommended that
the pump not be installed at a vertical distance greater than 2 meters.
If the suction tank is higher than the pump, an anti-siphon valve should
be installed to prevent accidental product leaks. Size the installation to
contain the back pressures caused by water hammering.
It is a good system practice to immediately install vacuum and air pressure
gauges at the inlets and outlets of the pump which allow verification that
operating conditions are within anticipated limits. To prevent the suction
pipes from being emptied when the pump stops, a foot valve should be
installed.
The suction pipe must have the following technical specifications:
- recommended minimum nominal diameter: 3/4";
- recommended nominal pressure: 10 bar;
- use pipes suitable for low pressure operation (e.g. with metal core)
M0204C
Publicidad
