Gas Pipe Sizing; Testing Gas Pressure/Gas Pressure Requirements - Pentair MASTERTEMP 125 Guide D'installation Et D'utilisation

GAS PIPE SIZING

STAGE TWO "LOW PRESSURE" GAS PIPE SIZING
PIPE SIZING FOR GAS LINE CONNECTIONS
MAXIMUM EQUIVALENT PIPE LENGTH
Natural Gas at 1000 B.T.U. per Cubic Foot
Propane Gas at 2500 B.T.U. per Cubic Foot
1/2" 3/4"
MODEL NAT PRO NAT PRO NAT PRO NAT PRO NAT PRO NAT PRO NAT PRO
125 - 20' 50' 80'
TESTING GAS PRESSURE
Before operating the heater, the heater and its gas connections must be leak tested. Do NOT use an open flame to test
for leaks. Test all gas connections for leaks with soapy water or another non-flammable method (see page 14).
The heater and its individual shut-off valve must be disconnected from the gas supply piping system during any pressure
testing of that system at test pressures in excess of 1/2 psig (3.5 kPa). The heater must be isolated from the gas supply
system by closing its individual manual shut-off valve during any pressure testing of the gas supply at test pressures
equal to or less than 1/2 psig (3.5 kPa).
CHECKING THE GAS PRESSURE THROUGH THE COMBINATION GAS CONTROL VALVE
Risk of fire and explosion. Improper installation, incorrect adjustment, alteration, service, or maintenance of the Combination
Gas Control Valve can lead to fire or explosion, causing loss of life, personal injury, and/or property damage. If it is necessary to
adjust the gas valve, this must be done by only by a qualified service agency. These instructions are for the use of qualified
service technicians only!
This appliance is equipped with an unconventional gas control valve that is factory set with a manifold pressure of –.2"
(–0.5cm) wc. Installation or service must be performed by a qualified installer, service agency, or the gas supplier. If
this control valve is replaced, it must be replaced with an identical control. The combination gas valve incorporates dual
shut-off valves and a negative-pressure regulator. For proper operation, the regulated pressure at the outlet manifold of
the valve must be –0.2" (–0.5cm) wc below the reference pressure at the blower mixer inlet, and the gas valve 'VENT'
tap must be connected to the end cap air orifice as shown in
adjusting the regulator setting. The correct gas regulator setting is required to maintain proper combustion and
must NOT be altered.
C
onnection for Service
To Air Flow
Switch
To Gas
Valve Vent
Figure 7.
CAUTION
The use of Flexible Connectors (FLEX) is NOT recom-
mended unless they are properly sized according to
the supplier recommendations for the heater rating.
Rev. C 3/2019
(Ft.)
1" 1-1/4" 1-1/2"
125' 250' 450' 600' - -
To Air Flow
Switch
To Low Side of
Differential Pressure Gauge
2" 2-1/2"
- - - -
Table 2.
WARNING
Figure 7. Do not attempt to adjust the gas input by
To Gas
Valve Vent
To High Side
of Differential
Pressure Gauge
Vent
Pressure Tap
GAS PRESSURE REQUIREMENTS
MASTERTEMP
NATURAL AND PROPANE:
MAXIMUM INLET: 14 INCHES W.C.
MASTERTEMP 125 Pool and Spa Heater Installation and User's Guide
Section 3. Installation
C
onnection for Test
Pressure Tap
Inlet
®
125 HEATER GAS PRESSURE:
15