Emerson Fisher 1305 Series Instruction Manual

Instruction Manual
D100342X012
October 2009
1305 Series Pressure Reducing Regulators
!
Fisher regulators must be installed,
®
operated, and maintained in accordance
with federal, state, and local codes, rules
and regulations, and Emerson Process
Management Regulator Technologies,
Inc. instructions.
If the regulator vents gas or a leak
develops in the system, service to the
unit may be required. Failure to correct
trouble could result in a hazardous
condition.
Call a gas service person to service the
unit. Only a qualified person must install
or service the regulator.
Introduction
The 1305 Series regulators are direct-operated,
pressure-reducing regulators that resist hydrate
formation and regulator freeze-up. Regulator freeze-
up resistance occurs as the pipeline gas warms the
finned inlet adaptor and the orifice area. As the gas
cools within the inlet adaptor due to pressure drop
and volume expansion, the warm inlet adaptor helps
keep the gas temperature above the freezing point
of water and the hydrate formation temperature. The
regulators are suitable for service with natural gas,
air, propane, and other gases compatible with the
internal parts.
Type 1305C—1 NPT inlet and 1/4 NPT outlet
connections; 5/64-inch (2,0 mm) orifice diameter.
Three springs provide 0 to 225 psig (0 to 15,5 bar)
reduced pressure ranges.
WaRnIng
W3101
Figure 1. 1305 Series Regulator with Tapped Lower
Casing Connection
Type 1305D—same as Type 1305C except with larger
spring case and just one heavy spring for reduced
pressure range of 200 to 500 psig (13,8 to 34,5 bar).
Principle of Operation
Downstream pressure is sensed by the diaphragm
(see Figure 3) through a registration hole in the
baffle. When downstream pressure rises, pressure
under the diaphragm overcomes the spring
compression and moves the valve lever upward.
This action pushes the valve disk closer to the
orifice, reducing flow through the body. Downstream
pressure returns to the setpoint value. When
downstream pressure decreases, the opposite action
takes place. The valve disk moves away from the
orifice, flow through the body increases, and the
downstream pressure returns to the setpoint value.
1305 Series