EMERSON Spence T61 Series Pneumatic Temperature Controller Instruction Manual
- June 4, 2024
- Emerson
Table of Contents
Instruction Manual
VCIMD-14960
Spence T61 Series Pneumatic
Temperature Controller
Spence T61 Series Pneumatic Temperature Controller
WARNING
Failure to follow these instructions or to properly install and maintain this
equipment could result in an explosion, fire, and/or chemical contamination
causing property damage and personal injury or death.
Emerson temperature controller must be installed, operated, and maintained in
accordance with federal, state, and local codes, rules, and regulations and
Emerson Process Management Regulator Technologies, Inc. (Emerson)
instructions. If the temperature controller 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.
Installation, operation, and maintenance procedures performed by unqualified
personnel may result in improper adjustment and unsafe operation. Either
condition may result in equipment damage or personal injury. Only a qualified
person shall install or service the T61 Series Pneumatic Temperature
Controllers.
Introduction
Scope of the Manual
This manual provides instructions for installation, maintenance and parts
information for the T61 Series pneumatic temperature controllers.
Product Description
The T61 Series Temperature Controller is ideal for wide-ranging, fast-changing
loads on instantaneous heaters and other difficult process applications. The
cascade principle, normally used only on instrument-type regulators, is the
basis for this design. T61 Series, used with a properly selected A Series
Pilot or Control Valve, continuously adjusts a pressure regulator to the
required heater pressure. This action, coupled with the fast response of a
bimetallic thermostat, gives exceptional results. Added convenience and
economy result from the wide (200°F / 93°C) adjustable range and the low air
consumption (0.35 cfm / 0.59 m3/h). These controllers have an adjustable
proportional band as well as over-temperature protection.
Type T61: For applications where air control signal decreases as process
temperature increases.
Specifications
The Specifications section gives some general specifications for the T61
Series pneumatic temperature controller.
The nameplates give detailed information about a specific controller as built
in the factory.
Available Configurations(1)
Type T61: Reverse Acting
Maximum Air Supply
32 psi / 2.21 bar
Maximum Signal Pressure
2 psi / 0.14 bar below supply
Maximum Inlet Pressure(2)
250 psi / 17.2 bar
Maximum Inlet Temperature(2)
400°F / 204°C
Temperature Ranges(2)
Type T61: 50 to 250°F / 10 to 121°C
Mounting
1/2 NPT| Air Connections
1/8 NPT
Air Consumption
Normal: 0.35 SCFM / 0.59 m3/hr
Maximum: 0.70 SCFM / 1.19 m3/hr
Proportional Band Adjustable
1/4 to 2 psi per 1°F / 0.02 to 0.14 bar per 17.2°C
Construction Materials
Body: Bronze
Seal: Viton®
Spool: Brass
Seat: Stainless steel
Spring: Stainless steel
Approximate Weight
2-3/4 lbs / 0.68 kg
---|---
- Reverse Acting is when the air control signal decreases as the process temperature increases. Direct Acting is when the air control signal increases as the process temperature increases.
- The pressure/temperature limits in this Instruction Manual or any applicable standard limitation should not be exceeded.
Principle of Operation
When Used with Regulator
The regulator is operated by its initial steam pressure. It is normally
closed, being held so by initial pressure on the disc and by an internal main
spring. The pressure pilot is actuated by means of an air signal applied to
its diaphragm. This signal is received from the temperature pilot as a result
of the temperature bulb sensing a drop in temperature from the control
setting.
When steam is turned on, it flows through the pressure pilot (Figure 3) to the
No. 8B tee. Bleedport No. 4A restricts the flow, builds pressure under the
diaphragm, and opens the main valve. Restriction No. 5A steadies the operation
of the regulator.
Steam flowing to the heater develops a rising delivery pressure which feeds
back through the control pipe to the pressure pilot diaphragm. As this
pressure approached a balance with the air pressure signal supplied by the
temperature pilot, the pressure pilot throttled. This, in turn, allows the
main valve to assume a position to maintain the set temperature. As the
temperature at the outlet of the heater increases, it causes the T61 Series
controller to reduce the loading pressure and this, in turn, will cause the
pressure regulator to modulate the steam flow to the heater.
When Used with Pneumatic Control Valve
The T61 Series controller sends a proportional air signal from 0 psi / 0 bar
to a maximum of 30 psi / 2.07 bar (not greater than 2 psi / 0.14 bar less than
the supplied pressure) within a 10-degree span. The pilot will increase the
signal as the temperature falls, which will either open or close the control
valve, depending upon the actuator configuration.
Installation
WARNING
Personal injury or system damage may result if this controller is installed,
without appropriate overpressure protection, where service conditions could
exceed the limits given in
the Specifications section and/or controller nameplate. Additionally, physical
damage to the controller may result in personal injury or property damage due
to escaping of accumulated gas. To avoid such injury and damage, install the
controller in a safe location.
All pressure equipment should be installed in a non-seismic area; should not
be exposed to fire, and should be protected from thunderbolt (lightning)
strikes.
△ CAUTION
The piping system must be adequately designed and supported to prevent
extraordinary loads to the pressure equipment. Ensure to blow out all lines
before making final connections.
Planning
- Locate the regulator in a horizontal pipe. Provide a trap ahead of the regulator to prevent water hammer and erratic operation.
- Use a strainer to avoid damaging effects of scale and dirt in pipelines to protect the regulator.
- Provide a three-valve bypass to facilitate inspection of the regulator without interrupting service.
Main Valve
- Flush the piping system thoroughly to clear it of welding beads, scale, sand, etc.
- Mount the main valve with the diaphragm chamber down and an arrow on the body pointing in the direction of flow.
- Mount screwed end valves in unions.
Pilot
-
Mount the pilot with the bulb projecting entirely into the liquid or air being controlled.
Note
If the body is not in a horizontal position with air gauges on top, loosen the set screw (key 5) on the bottom of the body nearest the bulb and rotate the body to a horizontal position. -
Retighten the set screw.
-
Connect a reliable source of clean compressed air (not to exceed 32 psi / 2.21 bar) to the inlet of the pilot.
-
Set the supply air at 2 psi / 0.14 bar above the maximum desired air signal. If air is available at a higher pressure, install a pressure-reducing valve.
-
Connect the pilot outlet to 1/4 in. / 6.35 mm tap on top of the pressure pilot.
Start-up and Setting
WARNING
The controller may be handling hazardous fluids. Only qualified personnel, who
are familiar with the installation should be permitted to install, readjust,
inspect or maintain the controller.
△ CAUTION
Insulation may be applied to the pilot body only. Do not insulate the bonnet.
-
Shut off the supply air.
-
Set the temperature adjusting knob at the lowest temperature setting.
-
Turn on the supply air. The supply air should be set at 2 psi / 0.14 bar above the maximum desired air signal.
Note If air is available at a higher pressure, install a pressure- reducing valve. No more than 1 to 2 lbs / 0.45 to 0.91 kg should show on the control air gauge (supplied with the T61 Series controller). -
Gradually turn up the temperature adjusting knob until rising loading air pressure causes the regulator to open. Continue raising the temperature setting in this fashion until desired control temperature is reached.
-
The T61 Series controller is factory set so that 5 degrees variation above and below the controlled temperature will cause the loading air pressure to vary approximately 8 lbs / 3.63 kg. The factory setting produces satisfactory control.
-
If closer control is desired, the sensitivity of the T61 Series controller can be increased by turning the sensitivity screw (key 7) clockwise. This will cause the control temperatures to move to a position below the set point. This effect must then be corrected by readjusting the temperature adjusting knob (key 4).
-
Adjust slowly, turning the sensitivity screw no more than 1/8 turn, and allow two to three minutes after each adjustment for the system to settle out. The practical range of adjustment of the sensitivity screw is 1/2 turn from the factory setting.
-
After the final setting is reached, release the set screw in the temperature adjusting knob and reposition it so that the indicator is aligned with the temperature being controlled. Retighten the set screw.
-
If the hunt develops (a steady swinging temperature) when the sensitivity is increased, the temperature pilot is being called on to function at a setting finer than the installation will permit. At this point, factors such as thermostat location, reexamine trapping and valve size.
-
If the regulator swings immediately on startup and does not settle out and decreasing the sensitivity by turning the sensitivity screw (key 7) counterclockwise cannot be tolerated, restudy the installation as a whole.
Maintenance
WARNING
To avoid personal injury, property damage, or equipment damage caused by the
sudden release of pressure or explosion of accumulated gas, do not attempt any
maintenance or disassembly without first isolating the controller from system
pressure and relieving all internal pressure from the controller. Controllers
that have been disassembled for repair must be tested for proper operation
before being returned to service. Only parts manufactured by Emerson should be
used for repairing this controller. Due to normal wear or damage that may
occur from external sources, this controller should be inspected and
maintained periodically. The frequency of inspection and replacement of parts
depends upon the severity of service conditions or the requirement of local,
state, and federal rules and regulations.
△ CAUTION
Do not, under any circumstances, loosen the bolts on the diaphragm chamber of
the T61 Series Temperature Controller or attempt to dismantle the thermostat
element. The system is filled with volatile fluid which, if lost, will render
the pilot inoperative.
Under normal conditions, complete dismantling at regular intervals is not
recommended. A valve kept relatively free of dirt will function for years with
minimum attention.
- Inspect for dirt collected at bleed port 4A and restriction elbow 5A.
- Inspect all joints for leakage. Keep bolts tight. Never allow a leak to persist.
Troubleshooting
WARNING
To avoid personal injury, property damage, or equipment damage caused by the
sudden release of pressure or the explosion of accumulated gas, do not attempt
any troubleshooting or disassembly without first isolating the controller from
system pressure and relieving all internal pressure from the controller.
Controllers that have been disassembled for repair must be tested for proper
operation before being returned to service. Only parts manufactured by Emerson
should be used for repairing this controller.
Failure To Open
- Check the supply gauge to be sure it shows 2 psi /0.14 bar higher than the required signal pressure.
- Turn the adjusting knob to the top of the temperature range. Pressure should go to within 2 or 3 lbs / 0.91 or 1.36 kg of supply pressure. If not, check for dirt in the sensitivity screw and ball seating surface.
Failure to Close of Overriding Delivery Pressure
- The adjusting knob may have been tampered with.
- If air pressure will not bleed down when the adjusting knob is turned to the bottom of range, it is likely that the vent is plugged in. The sensitivity screw (key 7) was improperly adjusted (open too wide).
Erratic Control
- Fast over and under rides are the result of fast load changes, usually accentuated by the thermostat being located at a point where it cannot immediately sense a change in conditions.
Installation Faults
- Poor circulation through the heater. Constant circulation should be employed.
- Traps on the return may be discharging erratically or may be improperly installed.
- Sticky check valve.
- High lift to condensate hot well. Gravity drainage from the heater should be arranged or return pumped installed.
Dismantling
- Remove the sensitivity screw (key 7) and clean it.
- Unlock the knob set screw. Loosen and move the adjusting knob (key 4) out to clear the stop on the dial plate and lock to the shaft.
- Unscrew the spool (key 3) from the body by rotating the adjusting knob counterclockwise.
- Carefully examine O-rings (key 6) for nicks and other defects.
- Examine the spool (key 3) and ball (key 2) for defects.
- Clean the spool and ball with air pressure.
- Reassemble.
Testing and Calibrating
Reverse Acting
For reverse-acting pilots, control pressure decreases with increasing
temperature.
- Plug the pilot control air port and apply supply pressure 2 psi / 0.14 bar above the control range to the supply air port.
- Open the sensitivity screw (key 7) one turn while establishing a steady system temperature.
- Turn the spool (key 3) clockwise to the point where the invar rod, ball, and seat are in contact. The control gauge should show pressure near the top of the control range.
- Turn the spool counter-clockwise until the control pressure is at the middle of the range.
- Continue to turn the spool counter-clockwise until the low end of the range is reached.
- Adjust the sensitivity screw as required so this occurs within a 5° change on the dial. The control pressure should vary from the minimum to the maximum (15 or 30 psi / 1.03 or 2.07 bar) with a 10° change of the dial setting. When used with an A-pilot the minimum is 3 psi / 0.21 bar, when used with a control valve the minimum is the lower end of the bench range.
Parts Ordering
When ordering parts, it is essential that the pilot type, service, and serial
number be stated. Select part by item number, but order by part number.
Specify the complete part number when ordering.
Parts List
| Key | Description | Part Number |
|---|---|---|
| 1 | Repair Parts Kit Type T61, Reverse Acting |
Bulb Assembly
Bronze Stainless steel| WAL08-11507-00
WAL07-40190-03
WAL07-40191-03
2| Ball, Stainless steel| WAL05-07709-00
3| Spool Reverse Acting Types T61, Brass| WAL04-07741-00
4| Adjusting Knob, Plastic| WAL05-07927-00
5| Body Set Screw, Steel| WAL05-11134-00
6| Spool Sealing Rings, Viton®| WAL05-04004-00
7| Sensitivity Screw, Steel| WAL05-07930-00
8| Valve Spring, Stainless steel| WAL05-05175-00
9| Pressure Gauge| WAL05-17460-00
10| 1/8 Nipple, Brass| WAL05-17459-00
11| 1/8 Tee, Brass| WAL05-17458-00
*These parts furnished in Repair Kit Viton® is a mark owned by E.I. du Pont de Nemours and Co.
VCIMD-14935 © 2021 Emerson Electric Co. All rights reserved 11/21. Spence is a
mark owned by one of the companies in the Emerson Automation Solutions
business unit of Emerson Electric Co. The Emerson logo is a trademark and
service mark of Emerson Electric Co. All other marks are the property of their
prospective owners. The contents of this publication are presented for
informational purposes only, and while every effort has been made to ensure
their accuracy, they are not to be construed as warranties or guarantees,
express or implied, regarding the products or services described herein or
their use or applicability. All sales are governed by our terms and
conditions, which are
available upon request. We reserve the right to modify or improve the designs
or specifications of such products at any time without notice.
Emerson Electric Co. does not assume responsibility for the selection, use or
maintenance of any product. Responsibility for the proper selection, use, and
maintenance of any Emerson Electric Co. product remains solely with the
purchaser.
Emerson Automation Solutions
Americas
McKinney, Texas 75070 USA
T +1 800 558 5853
+1 972 548 3574| Asia Pacific
Singapore 128461, Singapore
T +65 6777 8211
---|---
Europe
Bologna 40013, Italy
T +39 051 419 0611| The Middle East and Africa
Dubai, United Arab Emirates
T +971 4 811 8100
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>