OMM-0153_E
• 5/11/2023 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 21 of 124
CENTURION Installation, Operation & Maintenance Manual
SECTION 2: INSTALLATION
2.8.1 Gas Supply Specifications
Centurion Water Heaters require a stable natural gas or propane input pressure that complies
with the allowable gas inlet pressure range in the tables below:
CEN 2000/1600 Allowable NATURAL GAS Inlet Pressure for Standard and DBB Gas Trains
Minimum
Maximum
STANDARD GAS TRAINS
4.0” W.C. (1.00 kPa)
14.0” W.C. (3.49 kPa)
DBB GAS TRAINS
4.5” W.C. (1.12 kPa)
14.0” W.C. (3.49 kPa)
CEN 2000/1600 Allowable PROPANE Gas Inlet Pressure for Standard and DBB Gas Trains
Minimum
Maximum
STANDARD GAS TRAINS
8.0” W.C. (2.00 kPa)
14.0” W.C. (3.49 kPa)
DBB GAS TRAINS
8.0” W.C. (2.00 kPa)
14.0” W.C. (3.49 kPa)
Gas pressure must be measured when the unit is in operation at full fire. Measure the gas
pressure with a manometer at the NPT ball valve provided at the SSOV inlet. In a multiple
Water Heater installation, gas pressure must initially be set for single unit operation, and then
the remaining units must be staged on at full fire, to ensure gas pressures never falls below the
supply gas pressure when the single unit was firing.
All Centurion models have a low supply gas pressure switch in the gas train to prevent
operation if incoming gas pressure is insufficient.
2.8.2 External Gas Supply Regulator
An external gas pressure regulator is required on the gas inlet piping under most conditions
(see, below). Regulators must conform to the specifications in the following table:
CEN 2000/1600 Lock-Up Regulator Sizing
Required Volume
CFH
(m
3
/HR)
Natural Gas
2000
–
2300
(56.6
–
65.1)
Propane Gas
800
–
950
(22.6
–
26.9)
An external lock-up type regulator
MUST
be installed downstream of the isolation valve at all
installations where gas supply pressure will
exceed
14.0” W.C. (3.49 kPa)
.
C A U T I O N !
Centurion units must be isolated from the system when leak testing.
Drip legs are typically required at the gas supply of each unit to prevent any dirt, weld slag, or
debris from entering the
unit’s gas train inlet pipe. When multiple units are installed, some
utilities and local codes require a full-size drip leg on the main gas supply line in addition to the
drip leg at each unit. The bottom of the gas drip leg(s) should be removable without
disassembling any gas piping. The weight of the gas pipe must not be supported from the
bottom of the drip leg. The drip leg(s) must not be used to support any or part of the gas piping.
NOTE:
It is the responsibility of the customer to source and purchase the appropriate gas
regulator as described above. However, PVI offers for sale an appropriate regulator, which
may be ordered at the time of unit purchase or separately. Contact your PVI sales
representative for more information.
