N100, N100A, N110, and N120 Series
D450001T012
Instruction Manual
MCK-1008
March 2009
www.emersonprocess.com/regulators/lp
N100, N100A, N110, and N120 Series Differential
Bypass and Backpressure Valves
!
WARNING
Failure to follow these instructions or
to properly install and maintain this
equipment could result in an explosion,
and/or fire causing property damage and
personal injury or death.
Fisher
®
equipment must be installed,
operated, and maintained in accordance
with federal, state, and local codes
and manufacturer’s instructions. The
installation in most states must also
comply with NFPA. 58 or ANSI
standard K61.1.
Only personnel trained in the proper
procedures, codes, standards, and
regulations of the LP-Gas or Anhydrous
Ammonia industries should install and
service this equipment.
Introduction
Scope of the Manual
This manual covers instructions for the N100, N100A,
N110, and N120 Series Differential Bypass and
Backpressure Valves, shown in Figure 1.
Description
These valves are designed for use with propane,
butane, and anhydrous ammonia at ambient
temperatures. The valves can be used on other
compressed gases, but the user should check with
the factory to make sure the valve is suitable for the
particular service.
A 1/4 NPT tapped and plugged boss on the inlet side
of the body can be used to install a hydrostatic relief
valve or a pressure gauge.
The Types N100, N100A, and N110 have internal sensing
orifices so that no external sensing line is required.
N100 and N100A Series Bypass Valves
These valves are designed for bypass applications
on NPS 2 through 4 (DN 50 through 100) size pumps.
The throttling action of the valves allows only surplus
pump discharge to be returned to the tank.
N110 Series Bypass Valve
These valves are designed for bypass applications
on smaller pumps (5 to 40 GPM (18,9 to 151 l/min)
propane) used on stationary tanks or delivery trucks.
N120 Series Backpressure Valve
These valves are intended for use with smaller pumps
on cylinder filling applications. When installed after
the liquid meter, the Type N120 holds a differential
backpressure on the meter to prevent vapor from forming
within the meter. An external sensing line is required.
Figure 1.
Bypass and Backpressure Valves
TYPE N100
TYPE N110
TYPE N120
