Bell & Gossett HS 504F Series 1141 Temperature Regulators - Manual (Page 2)

OPERATING PRINCIPLE
This Series 1140 regulator automatically controls the
flow of steam, water or other medium passing through
its valve by responding to temperature changes at the
bulb. The bulb contains a liquid which vaporizes when
heated. Vapor pressure generated in bulb is transmitted
through the capillary tubing to the flexible bellows which
moves the valve disc or plunger controlling the flow of
the medium through the valve. Movement of the bellows
is opposed by a spring, providing a means of adjust-
ment. The regulator only controls within the temperature
range stamped on the name plate and can be adjusted
to control at any point within its range.
VALVE INSTALLATION
Before installing confirm proper sizing.
Oversized valves will not provide good
temperature control.
The location and installation of the regulating valve is
very important. A pipe line strainer must be installed
ahead of all double seated and balanced single seated
regulators. Single seated valves have built-in removable
strainers. However, it is still good practice to install a
strainer before all regulators and to blow all lines of
foreign matter on installation. See Figure No. 1.
The regulating valve should be installed as close as
possible to the unit being controlled. The regulator must
be installed in a vertical position, the bracket assembly
above the valve body. Install valve so that arrow cast on
valve body points in direction of steam or liquid flow.
When controlling steam, the heater or coil should be
properly vented and drained. A plain bucket trap should
not be used without some provision to eliminate air from
the coil. A drip trap should be installed ahead of all
steam regulators. See Figure No. 2.
When controlling flow of water used for cooling, the
valve can be installed on the supply end and may also
be installed on the discharge end of the unit. The
position depends largely on the particular case, as some
units, such as cylinder liners, cannot stand the full line
pressure.
When mixing hot and cold water, check valves should
be used on the supplies to the three-way valve, unless
the three way valve is used directly at heat exchanger
(see Figure No. 3) then check valve need only be on the
cold water side. To avoid temperature fluctuation of
tempered water line, the thermostatic bulb should be
located as close to three-way valve as possible.
These size valves are furnished with standard capillary
tubing, 10' (3m) length: 1/2" to 2" NPT and 2-1/2" to 4"
(65 to 100 mm).
Three-way valves are sometimes used as diverting
valves. See Figure No. 4.
C B
A
Outlet
HOT
IN
COLD
IN
2
Valves used to control heating cycles are direct acting,
i.e., they shut off on increase of temperature.
Valves used to control cooling cycles are reverse acting,
i.e., they open on increase of temperature.
Three-way valves are used to mix hot and cold water,
or as diverting valves (see Figure 3 and 4 below).
It is necessary that the sensing bulb be completely
immersed in the fluid being controlled.
C B
A
Inlet
Figure No. 1 - Trapping ahead of steam regulators
Figure No. 2 - Trapping ahead of steam regulators
Series 1140,
3-way valve
mixing service
When temperature
increases piston moves
down closing port ‘B’
opening port ‘C’.
Series 1140,
3-way valve
diverting service
When temperature
increases piston moves
down closing port ‘B’
opening port ‘C’.
Figure No. 3
Figure No. 4
OVER 10' (3 m)
PITCH TOWARD
STEAM REGULATOR
MAIN 1/2" PER FOOT
(15 MM PER 0.3 m)
STEAM
MAIN
TRAP
10' (3 m) OR LESS
PITCH TOWARD STEAM REGULATOR
MAIN 1/2" PER FOOT
(15 mm per 0.3 m)
STEAM
MAIN