Navien NFB-175 Mode D'emploi page 47

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 tables
1
●
2
on the proceeding pages for limitations. Avoid using
/ in corrugated connectors or tubing as noise may
1
2
occur.
Corrugated Connector
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
Excess Flow Valve
/ in.
3
4
CLOSE: 195
MAX OPER: 135
BYPASS: 5
Typical LP Gas piping examples:
2 Stage System with Multiple Regulators(Recommended)
Gas Regulator (2 Stage)
High Pressure
Regulator
Gas Tank
Single Regulator System
Gas Regulator
(12" WC)
Pipe
Gas Tank
Low Pressure Regulator
Full size
Gas Pipe
Full size
Gas Pipe
Full size
Gas Pipe
Connecting the Gas Supply 47