Gas Piping - NORITZ AMERICA CORPORATION NH199-DV Manuel D'installation Et Mode D'emploi

8.

Gas Piping

The appliance 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
The Appliance 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
The appliance and its gas connections must be leak tested before placing the appliance in operation.
The inlet gas pressure must be within the range specified. This is for the purposes of input adjustment.
In order to choose the proper size for the gas line, Installation must conform with local codes, or in the
absence of local codes, the National Fuel Gas Code, ANSI Z223.1/NFPA 54- latest edition and/or CSA
B149.1, Natural Gas and Propane Installation Code (NSCNGPIC).
A sediment trap must be installed upstream of the gas controls.
The sediment trap can be installed as illustrated to the right or as
allowed by applicable codes.
Gas Pressure
Size the gas line according to total btuh demand
of the building and length from the meter or
regulator so that the following supply pressures
are available even at maximum demand:
Natural Gas Supply Pressure
Min. 4" WC
Max. 10.5" WC
LP Gas Supply Pressure
Min. 8" WC
Max. 14" WC
Measuring Gas Pressure
[Primary gas pressure]
In order to check the gas supply pressure to the unit, a tap is pro-
vided on the gas inlet. Remove the hex head philips screw from the
tap, and connect a manometer using a silicon tube. (Right figure)
[Manifold pressure]
In order to check the gas manifold pressure, tap is are provided on
the gas valve inside the unit. The pressure can be checked either by
removing the hex head philips screw and connecting a manometer
with a silicon tube, or by removing the 1/8" NPT screw with an allen
wrench and connecting the appropriate pressure gauge.
Sample Gas Line
Noritz NH199-DV (199,900 Btuh)
Noritz NH150-DV (150,000 Btuh)
Outlet E
Clothes Dryer
(35,000 Btuh)
10'
Outlet C
5'
Section 4 Section 3 Section 2
5' 5'
5'
5'
Outlet D
10'
Gas Fireplace
(25,000 Btuh)
Natural Gas
Meter
**See next page for the pipe capacity charts.
Instructions
1. Size each outlet branch starting from the furthest
using the Btuh required and the length from the
Barbecue
(50,000 Btuh) meter.
2. Size each section of the main line using the
Outlet A
length to the furthest outlet and the Btuh
required by everything after that section.
10'
Section 1
Sample Calculation
10'
Outlet A: 45' (Use 50'), 50,000 Btuh requires 1/2"
Outlet B: 40', 65,000 Btuh requires 1/2"
5'
Section 1: 45' (Use 50'), 115,000 Btuh requires 3/4"
Outlet B
Outlet C: 30', 35,000 Btuh requires 1/2"
Gas Range Stove
Section 2: 45' (Use 50'), 150,000 Btuh requires 3/4"
(65,000 Btuh)
Outlet D: 25' (Use 30'), 25,000 Btuh requires 1/2"
Section 3: 45' (Use 50'), 175,000 Btuh requires 1"
Outlet E: 25' (Use 30'), NH199-DV (199,900 Btuh) requires 3/4",
Section 4: 45' (Use 50'), NH199-DV (374,900 Btuh) requires 1-1/4",
Follow the instructions from the gas supplier.
Gas Meter
Select a gas meter capable of supplying the entire
btuh demand of all gas appliances in the building.
Gas Connection
• Do not use piping with a diameter smaller than
the inlet diameter of the boiler.
• Flexible gas pipes not conforming to NH199-DV
(199,900 Btuh) or NH150-DV (150,000 Btuh)
standards are not recommended.
• Install a gas shutoff valve on the supply line.
• Use only approved gas piping materials.
NH150-DV (150,000 Btuh) requires 3/4",
NH150-DV (325,000 Btuh) requires 1-1/4".
1
⁄ psi (3.5 kPa).
2
1 ⁄ psi (3.5 kPa).
2
Gas supply valve
Drip leg
13