Section 2 — Installation
2-10 Part No. 750-363
2.7.4 Gas Piping
A dedicated pressure regulator is recommended for each CFLC boiler when the gas supply exceeds the
maximum values in Table 2-5. If below the referenced max. gas supply pressure and no step-down regulator
is installed, the CFLC gas train does not require gas venting (the pilot gas regulator may require a vent
limiter at its vent connection depending on the local code requirements).
The regulator for each boiler must be installed outside the boiler enclosure with at least 2 feet of pipe
between the regulator and the boiler gas valve connection. The discharge range of the regulator must be able
to maintain steady gas pressures as noted in Table 2-5.
For buildings or boiler rooms with gas supply pressure exceeding 14” WC (CFLC 4000/5000) or 2 psi (CFLC
6000-12000) a “full lock-up” type regulator is required.
In addition to the regulator, a full port plug type or “butterball” type gas shutoff valve must be installed
upstream of the regulator for use as a service valve. This is also required to provide positive shutoff and
isolate the unit during gas piping tests.
It is recommended that a strainer be installed upstream of the regulator or boiler gas connection to remove
debris from the gas supply.
Drip legs are required on any vertical piping at the gas supply to each boiler so that any dirt, weld slag, or
debris can deposit in the drip leg rather than into the boiler gas train. The bottom of the drip leg should
removable without disassembling any gas piping. The connected piping to the boiler should be supported
from pipe supports and not supported by the boiler gas train or the bottom of the drip leg.
All gas piping and components to the boiler gas train connection must comply with NFPA 54, local codes,
and utility requirements as a minimum. Only gas approved fittings, valves, or pipe should be used. Standard
industry practice for gas piping is normally Schedule 40 black iron pipe and fittings.
Before starting the unit(s) all piping must be cleaned of all debris to prevent its entrance into the boiler gas
train. Piping should be tested as noted in NFPA 54 and the boiler must be isolated during any tests.
After initial startup, the inlet screen to the gas valve should be checked and cleaned of any debris buildup
that may have resulted from installation.
See Figure 2-5 for a typical piping configuration.
The boiler and its individual shutoff 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 psi (3.5 kPa).
The boiler must be isolated from the gas supply piping system by closing its individual manual shutoff
valve during any pressure testing of the gas supply piping system at test pressures equal to or less than 1/
2 psi (3.5 kPa).
!
Caution
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