P-K Storm
TM
Gas Fired Boiler
Technical Service 1.877.728.5351
Revised: June 26, 2020
Released: June 26, 2020
©
Patterson-Kelley 2020
All Rights Reserved.
2691000273 P-K Storm ST2500-ST4000
Installation and Owners Manual Rev A.docx
Page 37
3.7 Piping
Gas Piping Overview
Before making the gas hook-up, make sure the boiler is being supplied
with the type of fuel shown on
the boiler nameplate.
The boiler shall be installed such that the gas
ignition system components are protected from
water (dripping, spraying, rain, etc.) during
appliance operation and service (circulator
replacement, control adjustment, etc.).
The boiler is factory fire-tested and adjusted for proper
combustion. The gas train components are certified to
handle a maximum inlet pressure of
14" W.C. (1/2 psig).
Typical gas pressure supply for natural gas is 7" W.C. If
the available gas pressure exceeds 14" W.C., a suitable
additional intermediate gas pressure regulator of the
"lock up" type must be provided to reduce the pressure
to less than 14" W.C. Refer to the table below or the
appliance’s label for the minimum inlet gas pressure.
ST-2500
ST-3000
ST-3500
ST-4000
Natural Gas
3.5” W.C
3.5
” W.C.
3.5” W.C.
3.5
” W.C.
This unit comes with a sediment trap (drip leg) already installed. Patterson-Kelley recommends a union
connection ahead of the primary manual shutoff valve on the boiler. A gas piping schematic is shown
above. Gas piping should be installed in accordance with National Fuel Gas Code, ANSI Z223.1, latest
edition, and any other local codes which may apply; in Canada see CAN/CSA-B.149.1, latest edition.
In the Commonwealth of Massachusetts, the gas cock must be a “T-handle type.”
Appliance Size (BTU/Hr)
Natural Gas Requirement
(CFH)
2,500,000
2500
3,000,000
3000
3,500,000
3500
4,000,000
4000
Natural Gas Piping
The table below should be used to size the natural gas piping to the appliance. The approximate
energy content of natural gas is 1,000 BTU / cu. Ft:
Simplified Gas Piping
Note:
When using a vented lock-up gas pressure regulator, the vent piping should be increased by
one pipe size for every 10 equivalent feet of length. Never connect vent piping that is smaller in size
than the gas regulator’s vent port connection.
