Navien NCB-180 Installation & Operation Manual page 33

Tighten the boiler connection valves with care to
Note
●
avoid damage.
The gas connection fitting on all boilers is
●
/ in rigid pipe can be used; refer to the sizing
1
●
2
tables on the proceeding pages for limitations.
Avoid using
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 boiler, to facilitate any future maintenance
or service.
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 boiler and may cause improper operation.
CLOSE: 195
MAX OPER: 135
BYPASS: 5
32 Connecting the Gas Supply
/ in corrugated connectors or tubing
1
2
Corrugated Connector
CLOSE: 195
MAX OPER: 135
BYPASS: 5
Excess Flow Valve
Typical LP Gas piping examples:
/ in
3
Single Regulator System
4
2 lb System with Multiple Regulators
1
/ "~
2
Gas Regulator
(12" WC)
1 3
/ "~ / " Pipe
4 8
Full size Gas Pipe
Gas Tank
Gas Regulator (2 lb)
3
/ " Pipe
8 2 psi 12" WC
1
/ " Pipe
2
Gas Tank
Full size
Gas Pipe
Full size
Gas Pipe