Navien NPE Installation & Operation Manual page 20

Tighten the water heater connection valves with
Note
care to avoid damage.
The gas connection fitting on all water heaters is
3
/ in.
4
1
/ in rigid pipe can be used; refer to the sizing
2
tables on the proceeding pages for limitations.
Do not use
as noise may occur.
When using flexible gas lines, ensure that the
pipe's inner diameter and connector is sufficient
to supply the required BTUs. Also, ensure that the
flexible line has no crimps or tight bends in it, as
this will restrict gas flow.
When using rigid pipe, Navien recommends the
installation of a union on the gas supply line
close to the water heater, to facilitate any future
maintenance or service.
Check with the local jurisdiction to verify whether
the use of
CAUTION
Prior to using an excess flow valve (EFV) in the gas line, check
the manufacturer's minimum and maximum flow capacity
rating. An improperly sized EFV will not allow for a full flow
of gas to the water heater and may cause improper operation.
CLOSE:
MAX OPER:
BYPASS:
20 Installing the Water Heater
1 / in corrugated connectors or tubing
2
Corrugated Connector
1 / " gas pipe is approved in the area.
2
CLOSE: 195
MAX OPER: 135
BYPASS: 5
195
135
5
Excess Flow Valve
Typical LP Gas piping examples:
2 Stage System with Multiple Regulators (Recommended)
Gas Regulators
(2 Stage)
High
Pressure
Regulator
Gas Tank
Single Regulator System
Gas Regulator
12 in W.C.
Pipe
Gas Tank
Low Pressure Regulator
(before entering
home or building)
Full Size
Gas Pipe
Full Size
Gas Pipe
Full size
Gas Pipe