Laars FT Series, Installation And Operation Instructions Manual

Page: 42 / 92

Page 42
Circulation pump
Check valve
Drain valve
valve
Backflow preventer
Pressure Relief Valve
Expansion tank
Differential
Pressure By-Pass
Air separator
(Diaphragm-type)
Automatic air vent
Anti-scald rated
Mixing Valve
PRIMARY LOOP
CH
SUPPLY
CH RETURN
(SPACE HEATING)
ZONE 1 ZONE 2 ZONE 3
1
1/4
”
Min
Piping
Do not
exceed
12"
See
Note
SECONDARY LOOP
(SPACE HEATING)
TO DR
AIN
P
P
Make-Up Water
TO DR
AIN
DHW OUTLET
DHW INLET
Circulation pump
Check valve
Drain valve
valve
Backflow preventer
Pressure Relief Valve
Expansion tank
Differential
Pressure By-Pass
Air separator
(Diaphragm-type)
Automatic air vent
Anti-scald rated
Mixing Valve
PRIMARY LOOP
CH
SUPPLY
CH RETURN
(SPACE HEATING)
ZONE 1 ZONE 2 ZONE 3
1
1/4
”
Min
Piping
Do not
exceed
12"
See
Note
SECONDARY LOOP
(SPACE HEATING)
TO DR
AIN
P
P
Make-Up Water
TO DR
AIN
DHW OUTLET
DHW INLET
4.15.4
Zoning with zone valves
- In a valve based system, there is one
circulator pump at the boiler and each
heating zone has a zone valve which opens
when the zone demands.
- Each thermostat is wired directly to the
corresponding zone valve. Contacts in
the zone valves provide a
proper signal to the boiler
when the valve is opened.
1. This piping diagram is meant to show system piping concept only. Installer is responsible for
all equipment and detailing required by local codes.
2. All closely spaced tees shall be 12” (or 4 pipe dia) center to center spacing.
3. A minimum of 6 pipe diameters of straight pipe shall be installed upstream and downstream
of all closely spaced tees.
4. The minimum pipe size of DHW piping should be 3/4” diameter.
5. Install a minimum of 12 diameters of straight pipe upstream of all circulators.
6. Install a check valve on the return line to the boiler.
7. Manufacturer strongly recommends the use of an anti-scald mixing valve at domestic hot
water outlet (boiler location) to reduce potential for scalding.Contact Manufacturer for
recommended models. Check with local codes.
Auto Fill Valve
and Backflow
Preventer Valves are
NOT included (Field
Supplied).