Thermal Solutions APEX APX425C Installation, Operating And Service Instructions page 57

7
Gas Piping
(continued)
E. Gas Piping for Multiple Boiler Installation
1. Individual module (boiler) gas pipe sizing specific
details - see Paragraph A.
2. Individual module (boiler) recommended gas
piping detail - see Figure 7-5.
3. An additional gas pressure regulator(s) may
need to be installed to properly regulate inlet
gas pressure at the smallest individual module
(boiler).
106308-05 - 3/23
APEX Installation, Operating, & Service Instructions
!
CAUTION
If gas pressure in the building is above ½ psig
(3.4 kPa), an additional gas pressure regulator
is required. Using one additional regulator
for multiple boilers may result in unsafe boiler
operation. The additional regulator must be able
to properly regulate gas pressure at the input
of the smallest boiler. If the regulator cannot
do this, two or more additional regulators are
required. Consult regulator manufacturer and/or
local gas supplier for instructions and equipment
ratings.
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