Spence Type N6 Differential Pressure Valves
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WARNING
Failure to follow these instructions or
to properly install and maintain this
equipment could result property damage
and personal injury or death.
Type N6 differential pressure valves
must be installed, operated and
maintained in accordance with federal,
state and local codes, rules and
regulations and Emerson Process
Management Regulator Technologies,
Inc. (Emerson) instructions.
If the valve vents gas or a leak develops
in the system, service to the unit may be
required. Failure to correct issue could
result in a hazardous condition.
Installation, operation and maintenance
procedures performed by unqualified
personnel may result in improper
adjustment and unsafe operation. Either
condition may result in equipment
damage or personal injury. Only a
qualified person shall install or service
the Type N6 differential pressure valves.
Introduction
Scope of the Manual
This manual provides instructions for the installation,
troubleshooting, maintenance, valve setting and parts
ordering for Type N6 differential pressure valves.
Product Description
Type N6 differential pressure valves are designed
to maintain pump discharge pressures at a constant
differential above a separate source of pressure.
When installed in a boiler feed pump discharge line
Figure 1.
Type N6 Differential Pressure Valves
November 2021
Instruction Manual
VCIMD-16088
as a by-pass valve, a connection from the stream
drum is made to the top chamber of the Type N6.
The desired differential is made by adjusting the
spring. The boiler feed-water pressure will then be
maintained by Type N6 at a constant pressure above
steam drum pressure by modulating the quantity of
water by-passed to pump section. When installed in
a by-pass line across a pumped system, Type N6
will maintain a constant differential of supply main
pressure over return main pressure by modulating the
quantity of by-passed water.
Type N6