Product Overview

Construction details
New polymer regulator
The flow rate regulator is made entirely of high resistance
polymer, specially chosen for use in air-conditioning and
hydraulic systems.
Its mechanical behaviour is excellent in a wide range of
working temperatures, it features high resistance to the
abrasion caused by continuous medium flow, it is insensitive
to the deposit of scale and is fully compatible with glycols
and additives used in circuits.
Exclusive design
With its exclusive design, the new regulator is able to
accurately regulate the flow rate in a wide range of operating
pressures. A special internal chamber acts as a damper for
beating and vibrations triggered by the medium flow, allowing
low noise operating conditions to the device.
For these reasons it can be used in systems both on zone
branch circuits and directly at the terminals.
Cartridge removal
The device is easy to remove for inspection or manual replacement
of the regulator, by unscrewing the cartridge locking nut from
the valve body.
Compact valve body with reduced dimensions
This special series of devices is also supplied with a compact,
simplified valve body for easy fitting on pipes and more cost-
efficient installations.
Sizing the circuit containing AUTOFLOW
®
valves is
particularly easy to accomplish. As illustrated alongside by the
example diagrams, calculation of the loss of head in order to
choose the pump is made by referring to the hydraulically
most unfavourable circuit and by adding this value to the
minimum differential pressure required by the
AUTOFLOW
®
. In
the example the circuits have the same nominal flow rate.
The
AUTOFLOW
®
devices, located on intermediate circuits,
automatically absorb the excess differential pressure to ensure
the corresponding nominal flow rate.
As the regulating valves open or close, the
AUTOFLOW
®
repositions itself dynamically to maintain the nominal flow rate
(50% load = circuits 3, 5, 7, 8 closed).
For more detailed information on sizing a system with
AUTOFLOW
®
, please refer to the 2nd volume of the Caleffi
Handbooks and the technical report “Dynamic balancing of
hydronic circuits”. They give theoretical calculations,
numerical examples and notes on the application of the
above-mentioned devices in circuits.
Sizing the circuit with AUTOFLOW
®
Flow rate table
Example
AUTOFLOW
®
127 series size 3/4”‚ with flow rate G
0
= 1,200 l/h and ∆p range 15 – 200 kPa:
∆p
required
= ∆p
AUTOFLOW
® = 15 kPa Pump head H = ∆p
circuit
+ ∆p
required
7654321 8
76543218
∆p absorbed by AUTOFLOW
®
at 100% load
extra ∆p absorbed by AUTOFLOW
®
at 50% load
minimum ∆p required by AUTOFLOW
®
Pump H
∆p in branch circuit
at nominal flow rate
Terminal
∆p along the circuit (flow and return)
Regulating valve
Differential pressures (∆p)
AUTOFLOW
®
Code
127141 ● ● ●
127151 ● ● ●
0,12; 0,15; 0,2; 0,25; 0,3; 0,35; 0,4; 0,5; 0,6; 0,7; 0,8; 0,9; 1,0; 1,2
0,12; 0,15; 0,2; 0,25; 0,3; 0,35; 0,4; 0,5; 0,6; 0,7; 0,8; 0,9; 1,0; 1,2; 1,4; 1,6
Size
∆p range
(kPa)
Flow rates (m
3
/h)
15–200
15–200
Minimum working
∆p (kPa)
15
15
1/2
3/4
Equal to the minimum working ∆p of the AUTOFLOW
®
cartridge (15 kPa).
Minimum differential pressure required