Powers 595 Series 11 Self-Operating Temperature Regulators - Type CD Composition Disc - Manual

Technical Instructions
IS-P-595CD
Table of Contents
■
Valve Description ..............................................................1
Operation ............................................................................1
Specifi cations ....................................................................2
Applications .......................................................................2
Sizing and Selection .........................................................3
Water Capacities .............................................................3
Steam Capacities .............................................................4
Product Identifi cation ......................................................5
Installation ..........................................................................5
Maintenance ......................................................................6
Dimensions .........................................................................8
Parts .................................................................................. 10
Accessories ................................................................... 12
Temp. Ranges/Bulb Sizes ............................................ 12
Order Code ...................................................................... 13
Preventive Maintenance.............................................. 14
Troubleshooting ............................................................. 14
Warranty Information ................................................... 16
#11 Regulator
Single Seat - Bronze Trim - Composition Disc
Valve Description
■
The Powers #11 Regulator is a self-actuating control valve
which automatically controls the temperature of a fl uid
without the use of external power. Adjust the set point and
the rugged self-operating #11 Regulator controls the fl ow
of heating medium (water or steam) to maintain a constant
temperature.
The instrument has a vapor pressure thermal system contain-
ing a thermally responsive fl uid. This thermal system rapidly
senses temperature changes at the bulb and controls the
fl ow of heating medium through the valve to maintain the
desired temperature. The thermal system features a two-ply
brass bellows with six reinforcing ribs on the bellows head
and thick capillary tubing walls to ensure long operating life.
The Powers #11 CD Regulator features:
• Tight shutoff when the valve is closed
• A valve stem of highly polished corrosion resistant grade
316L stainless steel to decrease friction and reduce
hysteresis
• An adjusting nut mounted on ball bearings and a removable
set point adjusting rod to ease set point adjustments
• A set point reference scale to aid temperature adjustments
Operation
■
A bulb is connected to a bellows containing a thermally
responsive fl uid. The bulb is inserted into the fl uid you are
trying to control (process fl uid) to sense its temperature.
The Regulator set point is adjusted to allow suffi cient fl ow of
heating medium (water or steam) through the valve to keep
the process fl uid at the desired temperature.
(A) When the termperature of the process fl uid drops below
the set point, the temperature of the thermally responsive
liquid decreases, which decreases the vapor pressure in the
bulb/bellows. The force of the resulting vapor pressure is less
than the spring force, so the bellows contract and the spring
extends, which raises the valve plug up from its seat. This
increases the fl ow of the heating medium (water or steam),
which raises the temperture of the process fl uid.
(B) As the process fl uid temperature increases toward or
beyond the desired set point, the temperature of the thermal-
ly responsive fl uid in the bulb increases, which causes the
vapor pressure to increase. This expands the bellows, com-
presses the spring, and moves the valve plug down towards
its seat, to reduce or stop the fl ow of the heating medium.
Temp.
Below
Set Point
Temp.
Above
Set Point
VAPOR
LIQUID
BULB
CAPILLARY
TUBING
SPRING
BELLOWS
VALVE
PLUG
VALVE
PLUG
VALVE SEAT VALVE SEAT
LIQUID
(A) (B)
1