Gas Supply Piping By Installer; Gas Bleeds And Vents; Boiler Water Piping; Piping Design - Patterson-Kelley Thermific Installation & Owner's Manual

®
Thermific Gas-Fired Boiler

3.7.1 Gas Supply Piping by Installer

The boiler and all gas piping connections should be
pressure-tested and must be checked for leaks before
being placed into service. Test with compressed air or
inert gas if possible.
The boiler must be disconnected at the boiler manual
shut-off valve (located at the end of the supplied gas
train) from the gas supply piping system during any
pressure testing of the system at pressures in excess of
1/2 psig (14 inch W.C.).
During any pressure testing of the gas supply piping
system at pressures equal to or less than 1/2 psig (14
inch W.C.), the boiler should be isolated from the gas
supply piping system by closing the manual shut-off.
Some leak test solutions, including soap and water,
may cause corrosion. These solutions should be
rinsed-off with water after testing.

3.7.2 Gas Bleeds and Vents

Outside Air
Gas Shutoff
(on Boiler
The bleed vents* on the diaphragm gas valves have
been factory-piped to terminate at the burner, as re-
quired by ANSI Z21.13. This feature provides com-
bustion of any gas which leaks past a ruptured dia-
phragm during operation. Gas vents to outdoor air
must be provided for the main pressure regulator. The
pilot regulator is equipped with a vent limiting device
and does not require external venting!
* When installing per ASME CSD-1, disconnect
factory piped bleed vents and vent the diaphragm
gas valves to outdoor air (field piping.)
Vent to
Drip Leg
Gas Pressure
Regulator
(on Boiler)
Gas Bleeds and Vents
Gas Vents by Installer
Note: Provide a drip leg, as shown, in the vent line.
All vent lines should be pitched up at all times to pre-
vent building a trap into the vent line.
Note: The vent line connection on the gas pressure
regulator must be piped to outdoor air by the installer
in accordance with the National Fuel Gas Code ANSI
Z223.1, latest edition, Sections 2.8.4 and 2.9.7.
If a N.O. vent valve is provided, it must be vented in-
dependently.
3.8 B
OILER

3.8.1 Piping Design

Water Flow in System
Ideal operation of the P-K Thermific
consist of a 20º F temperature differential across the
heat exchanger. The operating thermostat has an ad-
justable temperature differential. Insufficient flow
may result in excessive short cycling of the boiler and
eventual damage or premature failure of the equip-
ment.
In any case, Minimum Return Water Temperature
should be greater than 130º F to avoid problems of
condensation on the outside of the heat exchanger or in
the flue passages.
Proper flow rates and return water temperature may be
achieved through a combination of primary and secon-
dary flow loops. Multiple zones and pumps may result
in different flow rates at different times. Considera-
tion must be given to all possible conditions and their
consequences.
Piping With Refrigeration Machines
When used with a refrigeration system, the boiler shall
be installed so that chilled medium is piped in parallel
with the boiler. Valves should be installed to prevent
chilled water from entering the boiler when the system
is operated in the cooling mode.
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ATER IPING
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Installation
Boiler would