cashco 135 Instruction manual

INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM) IOM-135
06-02
MODEL 135
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.
TheModel135thermalprobeisnotastand-alonedevice.Itisprimarilyusedwithapressureloadedreducingregulator
with fail-close action upon loss of loading pressure. Used with any compatible fluid that can be vented to atmosphere
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, flow restricting orifices and a main regulator, such as the Model DA4. Refer to Section II of this
IOM for PTCM principles of operation and SECTION III for system installation.
SECTION II
II. PRINCIPLES OF OPERATION
1. As the Model 135 thermal probe (5) external
sheath is exposed to lower temperatures, it con-
tracts in length. The internal Invar rod remains
unchanged in length, pushing a ball/plug away
fromitsseat,allowingtheinletgaspressuretobe
"vented".
2. ThePTCMlowtemperatureprotectionisprovided
through the Model 135 thermal probe (5). When
the fluid is approximately 8°F (4.5°C) above the
setpoint, the Model 135 thermal probe (5) will
begin to open, lowering the loading pressure and
thereby the delivery pressures. The delivery flow
rate is reduced by this action. When the fluid is at
the setpoint, the Model 135 thermal probe will
reduce the loading pressure to 5 psig (.34 Barg),
essentially closing the main regulator (7). When
thefluidisslightlybelow setpointthemainregula-
tor (7) will close tight.
SECTION III
III. INSTALLATION
1. Insert the Model 135 thermal probe (5) in the
upstreampipelinerequiringcontrol. Seal the1/2"
(DN15) NPT threads with process compatible
threadsealantandturnclockwise(CW)untiltight.
2. PTCM Start-up:
a. TheModel135thermalprobe(5)temperature
isfactorycalibratedpercustomer'sorderspeci-
fications.
b. Isolationblockvalves(9,10)areopenandthe
bypass valve (8) should be closed. Upon
start-up,thePTCMbecomespressurizedfrom
the storage tank as normal operating pres-
sure is obtained.
c. ForPTCMwithUnloadingBackpressureValve
see Figure 2. The delivery pressure is set by
the adjusting screw on the backpressure un-
loadingvalve(1). Adjusttheloadingpressure
untilthegauge(6)readsnominally6psig(.41
Barg) higher than the customer specified de-
livery pressure.

IOM-1352
Control Head
Body
Body Flat
External Sheath
Invar Rod
1/2" (DN15) NPT
Insertion Threads
Set Screw
Outlet Vent
Figure 1: Model 135
d. After desired delivery pressure is set, tighten
the lock nut on the pressure adjusting screw.
3. Themainregulator(7)willrespondtoanincrease
indemandinlessthantenseconds.Thepressure
SECTION IV
allpressure is relieved, close isolation block valve
(10). The by-pass valve (8) can then be reopened
to supply customer with process gas while the
Model 135 thermal probe (5) is removed and
replaced.
3. Emergency temperature adjustments can be per-
formed if mandatory (see Figure 1). Loosen set-
screws on the body to allow adjustments. The
adjustments occur between the control head and
themilledflatsonbody.Thecontrolheadisturned
counter-clockwise (CCW) to lower the tempera-
ture setpoint. A clockwise (CW) rotation will raise
the temperature setpoint. Make adjustments in
incrementalstepsnottoexceedfivedegreesrota-
tion. After desired temperature setpoint is ob-
tained,tightensetscrews. NOTE:
Allowsufficient
time for temperature to stabilize before checking
temperature setpoint after each adjustment.
1. The Model 135 thermal probe (5) is shipped from
thefactorypresetper the customer'sorderspeci-
fications.Allmaintenanceshouldbeperformedat
the factory.
IV. MAINTENANCE
willinitiallytakeasmall dip andrebuildtosetpoint
over this period. Response to a reduction in de-
mand is immediate. An overshoot of 2-3 psi
(.14-.21 Bar) in the customer delivery pressure
can be expected.
!
2. To relieve pressure for removal and replacement
of Model 135 thermal probe (5), shutoff by-pass
valve(8)andisolationblockvalve(9).Bleeddown
pressure through isolation block valve (10). After
WARNING 1
SYSTEM UNDER PRESSURE. Relieve all pressure
prior to performing any maintenance on the PTCM.
Failure to do so could result in personal injury.

IOM-135 3
A. No supply pressure to PTCM. A. Check gauges.
B. Lockout valves closed. B. Open valves.
C. Unloading valve incorrectly set. C. Reset.
D. Model 135 thermal probe vent leaking. D. Under normal operating conditions, there should be no flow coming from
the outlet vent. If there is flow and the temperature of the gas is not
suspect then replace the Model 135 thermal probe.
E. Upstream filter/orifice blocked. E. Inspect and replace if necessary.
F. Unloading valve malfunction. F. Inspect and replace if necessary.
G. Leaking or broken fitting. G. Inspect and replace if necessary.
H. Main regulator stuck closed. H. Verify dome pressure.
I. Strainer blocked. I. Inspect and replace if necessary.
VI. TROUBLE SHOOTING GUIDE
Possible Causes
1. No/Low Flow or Pressure at Normal Operating Temperatures.
SECTION VI
Remedies
Remedies
Possible Causes
A. Backpressure valve failed. A. Inspect and replace if necessary.
B. Upstream filter/orifice blocked. B. Inspect and replace if necessary.
C. Leaking or broken fitting. C. Inspect and replace if necessary.
D. Diaphragm in main regulator failed. D. Inspect and replace if necessary.
2. Poor Pressure Control
Remedies
Possible Causes
A. Main regulator seat leakage. A. Inspect and replace if necessary.
B. By-pass valve leaking. B. Inspect and replace if necessary.
3. Delivery Pressure Rise at No/Low Flow
SECTION VII
VII. REORDERING INFORMATION
1. Contact your local Cashco, Inc. sales representative and specify temperature calibration desired.
SECTION V
V. CALIBRATION
1. The Model 135 thermal probe (5) should be calibrated at the factory.

3
8
7
9
34
5
FF
P1
P1
4
6
1
10
P1
VTA VTA
Vent to a
Safe Location
DA3, DA4, DAP*
11
12
Vent to a
Safe Location
P1
P1
P1
F
ExternalSensing
if required.
VenttoaSafe
Location
VTA
DA4, DAP*
VTA
9
5
8
4
13 2
6
14
12
4
7
12
10
8
Item No. Description
1 Unloading Backpressure Valve
2 Pressure Loaded Pilot Valve
3 Inline Filter
4 Restriction Orifice
5 Model 135 Thermal Probe
6 Gauge
7 Main Regulator
8 By-pass Valve
9 Isolation Block Valve
10 Isolation Block Valve
11 Pressure Gauge
12 Optional Gauge
13 Stabilizer Pressure Reducing Valve
14 Setpoint Backpressure Valve
15 Needle Valve
Typical KM pressure loaded reducing
regulator used with Model 135 Thermal
Probe.
External Sensing
if required.
Figure 2: PTCM System with
Pressure Loaded Main Regulator
(see DA3, DA4, DAP IOM's for
maintenance on main regulator).
Figure 3: PTCM System with
Pilot Operated Main Regulator
(see DA4, DAP IOM's for
maintenance on main regulator).
Cashco, Inc.
P.O. Box 6
Ellsworth, KS 67439-0006
PH [phone]
Fax [phone]
e-mail: [email protected]
[email protected]
Printed in U.S.A. IOM-135 -dlb
*
VenttoaSafe
Location
11
P1