Cashco 135 Low Temp Thermal Probe - Manual

INSTALLATION, OPERATION, & MAINTENANCE
MANUAL IOM
MODEL 135
PNEUMATIC CONTROLLER
LOW TEMPERATURE SHUTOFF
SECTION I
I. DESCRIPTION AND SCOPE
The Model 135 thermal probe is a low temperature shutoff device with an integral, rigid insertion bulb used to protect
downstream piping systems and equipment from experiencing temperature excursions below desired minimum
operating temperature due to equipment malfunction or customer overdraw of system capacity. This is NOT a
SAFETY DEVICE.
The Model 135 is not a stand-alone device. Primarily installed with a pressure loaded reducing regulator with
fail-close action upon the loss of loading pressure. It is used with any compatible fl uid that can be vented to atmo-
sphere in an environmentally acceptable method. This combination of equipment is known as a PRESSURE/LOW
TEMPERATURE CONTROL MODULE (PTCM). It typically consists of a Model 135 thermal probe, an unloading
backpressure valve, fl ow restricting orifi ces and a main regulator.
IOM-135
12/13
SECTION II
II. PRINCIPLES OF OPERATION
III. INSTALLATION
As the Model 135 thermal probe external sheath is
exposed to lower temperatures, it contracts in length.
The internal Invar rod remains unchanged in length,
pushing a ball/plug away from its seat, allowing the
inlet gas pressure to be "vented".
The PTCM low temperature protection is provided
through the Model 135 thermal probe. When the fl uid
1. Inspect the SST tag on the Model 135 and note
the Calibration and Re-Calibration dates. If
the Re-Calibration date has expired, return the
Model 135 to Cashco. Inc, for recalibration. If
the tag is missing do not install the unit, return
it to Cashco. Inc,. Each probe is factory cali
brated per customer's order and set point specifi
cations.
2. Prior to installation, check that the Model 135
operates within the desired window for the set
point. If it does not operate correctly, return it to
Cashco.
Inc,.
3. Apply a compatible sealant to the 1/2" (DN15)
NPT threads and insert the Model 135 probe
into the upstream pipe line requiring control.
With a wrench, secure the fl at surfaces on the
body and rotate the probe clockwise (CW) until
probe is tight. See Figure 1.
is approximately 8°F (4.5°C) above the setpoint, the
Model 135 thermal probe will begin to open, lowering
the loading pressure and thereby the delivery pres-
sures. The delivery flow rate is reduced by this action.
When the fluid is at the setpoint, the Model135 thermal
probe will reduce the loading pressure to 5 psig (.34
Barg),essentially closing the main regulator. When
the fluid is slightly below setpoint the main regulator
will close tight.
SECTION III
CAUTION
Setpoint for the probe can shift if it is mis-handled
prior to installation.