Lochinvar Knight 80 - 285 - Manual (Page 28)

Installation & Operation Manual
28
6
Hydronic piping
System water piping methods
The Knight is designed to function in a closed loop
pressurized system not less than 12 psi. A temperature and
pressure gauge is included to monitor system pressure and
outlet temperature and should be located on the boiler outlet.
It is important to note that the boiler has a minimal amount
of pressure drop and must be figured in when sizing the
circulators. Each boiler installation must have an air
elimination device, which will remove air from the system.
Install the boiler so the gas ignition system components are
protected from water (dripping, spraying, etc.) during
appliance operation for basic service of circulator
replacement, valves, and others.
Observe a minimum of 1 inch clearance around all
un-insulated hot water pipes when openings around the pipes
are not protected by non-combustible materials.
Low water cutoff device
On a boiler installed above radiation level, some states and
local codes require a low water cutoff device at the time of
installation.
Chilled water system
If the boiler supplies hot water to heating coils in air handler
units, flow control valves or other devices must be installed to
prevent gravity circulation of heater water in the coils during
the cooling cycle. A chilled water medium must be piped in
parallel with the heater.
Freeze protection
Freeze protection for new or existing systems must use glycol
that is specially formulated for this purpose. This includes
inhibitors, which prevent the glycol from attacking the
metallic system components. Make certain to check that the
system fluid is correct for the glycol concentration and
inhibitor level. The system should be tested at least once a
year and as recommended by the producer of the glycol
solution. Allowance should be made for the expansion of the
glycol solution in the system piping.
3. Install purge and balance valve or shutoff valve and drain
on system return to purge air out of each zone.
4. Install a backflow preventer on the cold feed make-up water
line.
5. Install a pressure reducing valve on the cold feed make-up
water line, (15 psi nominal). Check temperature and
pressure gauge (shipped separately), which should read a
minimum pressure of 12 psi.
6. Install a circulator as shown on the piping diagrams in this
section. Make sure the circulator is properly sized for the
system and friction loss.
7. Install an expansion tank on the system supply. Consult the
tank manufacturer’s instruction for specific information
relating to tank installation. Size the expansion tank for the
required system volume and capacity.
8. Install an air elimination device on the system supply.
9. Install a drain valve at the lowest point of the system.
Note: The boiler cannot be drained completely of water
without purging the unit with an air pressure of 15 psi.
10. This appliance is supplied with a relief valve sized in
accordance with ASME Boiler and Pressure Vessel Code,
Section IV (“Heating Boilers”). Pipe the discharge of the
safety relief valve to prevent injury in the event of pressure
relief. Pipe the discharge to a drain. Provide piping that is
the same size as the safety relief valve outlet. Never block
the outlet of the safety relief valve.
See the *piping illustrations included in this section, FIG.’s 6-4
thru 6-9 for suggested guidelines in piping the Knight boiler
with either zone valves or circulator pumps.
*Please note that these illustrations are
meant to show system piping concept only,
the installer is responsible for all equipment
and detailing required by local codes.
Use only inhibited propylene glycol
solutions, which are specifically
formulated for hydronic systems. Ethylene
glycol is toxic and can attack gaskets and
seals used in hydronic systems.
ƽ WARNING
NOTICE
General piping information
Basic steps are listed in this section along with illustrations on
the following pages (FIG.’s 6-4 thru 6-9), which will guide you
through the installation of the Knight boiler (reference
FIG. 6-2).
1. Connect the system return marked “Inlet”, make sure to
install with pipe sealant compound.
2. Connect the system supply marked “Outlet”, make sure to
install with pipe sealant compound.
Relief valve and temperature and pressure
gauge installation
Basic steps are listed below to guide you through the installation
of the relief valve and the temperature and pressure (T & P)
gauge provided with the unit.
1. Install the tee with the 3/4 inch fitting positioned
vertically and on the top as shown in FIG. 6-1.
2. Install the relief valve into the 3/4 inch fitting of the tee
installed in Step 1 (FIG. 6-1).
3. Install a field provided close nipple and tee with the fitting
positioned vertically on the top on the downstream
side of the relief valve (see FIG. 6-1).
4. Install the temperature and pressure gauge provided with
the unit into the top fitting of the tee (a bushing may be
necessary) installed in Step 3 (FIG. 6-1).
ƽ WARNING
The relief valve, tee and any necessary
fittings are shipped in the install kit with the
boiler and are to be field installed (FIG. 6-1).