User Guide

Function
The automatic filling valve is a device consisting of a pressure reducing valve with
compensating seat, visual system pressure setting indicator, an inlet filter, anti-scale
internal parts, a shut-off valve and a check valve.
It is installed on the water inlet piping in sealed heating systems, and its main function
is to maintain the pressure of the system stable at a set value, automatically filling up
with water as required.
This valve has been designed as pre-adjustable, which means that it can be
adjusted at the required pressure value before the system charging phase.
After installation, during the filling or topping-off phase, the water feed will stop when
the set pressure is reached filling 50% faster than other valves. There are no levers to
flip or valve to close.
Pre-assembled with the 573 series backflow preventer, the AutoFill
™
Combo features
an atmospheric vent which is designed to protect drinking water systems from return
flow, caused by back-siphoning or back pressure, of contaminated fluids. The 573
series has been specifically certified to standards CSA B64.3 and ASSE 1012.
These items are designed for use in closed hydronic systems. Do not use in plumbing
applications. These items do not meet the low-lead plumbing standards of U.S. and
Canada.
Pre-adjustable filling units
553 Series
38467.05
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553542A ½” M NPT inlet x ½" FNPT outlet
553549A ½” sweat inlet x ½" FNPT outlet
553642A ½” M NPT inlet x ½" FNPT outlet / gauge
553649A ½” sweat inlet x ½" FNPT outlet / gauge
553
Filling unit
Materials - body: brass
- cover: PA 66 GF 30
- seals: NBR
Performance
Suitable fluids: water, glycol solution
Max. percentage of glycol: 50%
Max. working pressure: 230 psi (16 bar)
Pressure setting range: 3–60 psi (0.2–4 bar)
Factory setting: 15 psi (1.035 bar)
Indicator accuracy: ±2 psi (±0.15 bar)
Max. working temperature: 150°F (65°C)
Pressure gauge scale: 0-60 psi / 0-6 bar)
Connections - 553542A 1/2" NPT male inlet x 1/2" NPT female outlet
- 553549A 1/2" sweat inlet x 1/2" NPT female outlet
- 553642A 1/2" NPT male inlet x 1/2" NPT female outlet
- 553649A 1/2" sweat inlet x 1/2" NPT female outlet
Product Range
Technical
Specifications
ASSE 1012
1