Trim Piping; System Piping - HELIX VX-399 Installation, Operation & Maintanance Manual

!
WARNING
Burn and scald hazard. Safety relief valve could
discharge steam or hot water during operation.
Install discharge piping per these instructions.
FIGURE 5-2 Safety Relief Valve Discharge Piping
(View Right side of Boiler)
Check Local Codes
For Maximum
Distance To Floor
FIGURE 5-3 Limit Control, Limit Well, and Plug
(View Left Side of Boiler)
*Aquastat
Limit Control
*Limit Well ½"
Supply Water
*Tee 1¼" x 1¼"
x ¾"
*1¼" Close
Nipple
Controls Tree
* Included in optional accessory kit.
5 - HYDRONIC PIPING
Safety Relief
Valve
Temperature
Pressure
Gauge
• Use pipe suitable for temperatures of 375°F (191°C)
or greater.
• Individual boiler discharge piping shall be independent
of other discharge piping.
• Size and arrange discharge piping to avoid reducing
safety relief valve relieving capacity below minimum
relief valve capacity stated on rating plate.
• Run pipe as short and straight as possible to location
protecting user from scalding and properly drain
piping.
• Install union, if used, close to safety relief valve outlet.
• Install elbow(s), if used, close to safety relief valve
outlet and downstream of union (if used).
• Terminate pipe with plain end (not threaded).
• Arrange piping to prevent water dripping onto boiler.
5.4 Low Water Cutoff (LWCO) and Aquastat
• Unit shipped with LWCO installed.
• Optional manual reset Hi limit if required, connect
wires and remove factory jumper to terminal strip.
Maximum limit setting is 190°F (88°C). Use thermal
grease.

5.5 Trim Piping

• Temperature - Pressure Gauge. Install temperature
pressure gauge using bushings provided with boiler.
See Figure 5-1 and 5-3.
• Protect chassis grommets from heat damage.

5.6 System Piping

• See Table 3 for basic system piping configurations.
• See Table 3 for general boiler pump sizing
requirements.
• Systems with automatic fill valves require back flow
prevention device.
• Single boiler system. See Figure 5-5 through 5-7 for
general guidance. Additional considerations:
• Boiler control is designed for single central heating
pump. Installer responsible for integration of
multiple central heating pumps.
• Boiler control allows domestic hot water
prioritization. Function could be lost if central
heating pump not directly connected to control
system.
• Multiple boiler system. See Figure 5-8A, B & C for
general guidance. Additional considerations:
• Control system requires equivalent water
temperatures entering each boiler to properly
sequence and adjust system supply temperature.
• Install multi boiler sensor kit. See "Parts, Kits &
Optional Accessories" manual for part number.
• * Boiler control provides integrated manual reset high
limit as primary limit control. Optional Aquastat Kit is
for those jurisdictions with this requirement. See figure
5-3.
12
P/N 240010943, Rev. C [09/07/2016]