Dwyer 38R User Manual
Series 38R
Self-Operating Temperature Regulators
Operation, Installation & Maintenance Manual
Indicating and Non-indicating
Actuator Option 2 Shown
Bulletin V-10
Operation, Installation & Maintenance Manual
Series 38R ••• Self-Operating Regulators
Operation, Installation & Maintenance Manual
Page 2
Principles of Operation of the Regulator 3
Identifying Your Unit
Pressure and Temperature Limits 4
Regulator – Installation 5
Sensing Bulb – Location & Installation 6
Placing Regulator into Operation & Setting Control Point 7
Routine Service 8
Stem Seal Packing 9
Checking the Regulator for Proper Action 10-11
Valve Body Assembly 12-13
Reversing the Valve Action 14-15
3-Way Regulator – Installation & Maintenance 16
Option 3 – “Fail-Safe” Installation & Maintenance 17
Typical Applications 18-19
Typical Heat Exchanger Application Using a Self-Op 2-Way Valve
Typical Heat Exchanger Application Using a Self-Op 3-Way Diverting Valve
Typical Plumbing for a Self-Op 3-Way Mixing Valve
Typical Water Application Using a Self-Operating Regulator
Typical Fuel Storage Application Using a Self-Operating Regulator
Typical Plating or Pickling Application Using a Self-Operating Regulator
Trouble-Shooting 20-21
TABLE OF CONTENTS
Series 38R ••• Self-Acting Temperature Control Valves
Operation, Installation & Maintenance Manual
PRINCIPLES OF OPERATION OF THE REGULATOR
The W.E. Anderson Model 38R Temperature Regulator operates on the vapor pressure principle. The thermally
sensitive bulb of the instrument contains a fluid that creates a vapor which increases or decreases in pressure as the
sensing bulb temperature increases or decreases. This vapor pressure is transmitted hydraulically to the bellows
which, opposed by the adjusting (return) spring, actuates the valve controlling the flow in proportion to the sensed
temperature at the bulb. Raising or lowering the adjusting screw will change the compression of the spring against the
bellows, thus raising or lowering the control temperature. For the most sensitive operation a nominal range should be
selected that contains the desired control point in the upper 1/3 of the nominal range. The vapor pressure response is
greater per unit of temperature change in the upper portion of the nominal range. All W.E. Anderson temperature
regulators (with the exception of the Option 3 “Fail-Safe”) are equipped with an over-range feature which allows
the bulb to be heated 100°F above the nominal range without damaging the temperature sensing system.
Recomme nded Working Span
Single Seat Heating Va l v e s
Double Seat Heating Va l v e s Single Seat Cool ing Va l v e s
Double Seat Cooling Va l ve s ˚ F (˚C) Dial Thermometer Range
R a n ge Code Nominal Range All 3-Way Va l v es ˚ F (˚C) ˚ F (˚C)
R01* 20° to 70°F (-7 to 21) 40° to 65°F (4 to 18) N/A 30° to 115°F (-1 to 46)
R02* 40° to 90°F (5 to 32) 65° to 85°F (18 to 29) N/A 50° to 140°F (10 to 60)
R03 30° to 115°F (-1 to 46) 85° to 110°F (29 to 43) 50° to 80°F (10 to 27) 30° to 115°F (-1 to 46)
R04 50° to 140°F (10 to 60) 110° to 135°F (43 to 57) 80° to 105°F (27 to 41) 50° to 140°F (10 to 60)
R05 75° to 165°F (24 to 74) 135° to 160°F (57 to 71) 105° to 130°F (41 to 54) 75° to 165°F (24 to 74)
R06 105° to 195°F (41 to 91) 160° to 190°F (71 to 88) 130° to 155°F (54 to 68) 105° to 195°F (41 to 91)
R07 125° to 215°F (52 to 102) 190° to 210°F (88 to 99) 155° to 180°F (68 to 82) 125° to 215°F (52 TO 102)
R09 155° to 250°F (68 to 121) 210° to 245°F (99 to 118) 180° to 215°F (82 to 102) 155° to 250°F (68 TO 121)
R10 200° to 280°F (93 to 138) 245° to 275°F (118 to 135) 215° to 245°F (102 to 118) 200° to 280°F (93 TO 138)
R11 225° to 315°F (107 to 157) 275° to 310°F (135 to 152) 245° to 280°F (118 to 138) 225° to 315°F (107 TO 157)
R12 255° to 370°F (124 to 188) 305° to 365°F (152 to 185) 275° to 335°F (135 to 168) 255° to 370°F (124 TO 188)
R13 295° to 420°F (146 to 216) 365° to 415°F (185 to 213) 335° to 385°F (168 to 196) 295° to 420°F (146 TO 216)
R14 310° to 440°F (154 to 227) 415° to 435°F (213 to 224) 385° to 405°F (196 to 207) 310° to 440°F (154 TO 227)
*Not recom mended for single se ated valves .
STANDARD RANGES
Option 3 Fail-Safe Actuators
R a n g e Nominal Range
C o d e and Recommended Working Span
R 8 1 40° to 65°F (4 to 18)
R82 55° to 80°F (18 to 29)
R83 65° to 90°F (18 to 32)
R84 80° to 110°F (27 to 43)
R85 90° to 115°F (32 to 46)
R86 110° to 140°F (43 to 60)
R89 140° to 175°F (60 to 79)
R90 170° to 195°F (77 to 91)
R91 190° to 210°F (88 to 91)
R92 205° to 225°F (96 to 107)
R93 215° to 250°F (102 to 121)
R94 230° to 265°F (110 to 129)
R95 245° to 280°F (118 to 138)
R96 270° to 300°F (132 to 149)
IDENTIFYING YOUR UNIT –
Option 1 & Option 2 Actuators
Page 3
Series 38R ••• Self-Acting Temperature Control Valves
Operation, Installation & Maintenance Manual
Page 4
MAXIMUM PSI DROP THRU VALVE, PSI (bar)
Indicating & Non-Indicating Actuator Options 1 & 2
Valve Single Seated Double Seated 3-Way Fail-Safe
1
/2” 250 (17.3)
_
250 (17.3) 100 (6.9)
3
/4” 140 (9.7) 250 (17.3) 250 (17.3) 250 (17.3)
1” 80 (5.5) 250 (17.3) 250 (17.3) 250 (17.3)
11/4” 50 (3.4) 250 (17.3) 250 (17.3) 175 (12.1)
11/2” 35 (2.4) 250 (17.3) 250 (17.3) 150 (10.3)
2” 20 (20) 250 (17.3) 250 (17.3) 100 (6.9)
21/2”
_
65 (4.5) 125 (8.6)
_
3”
_
50 (3.4) 125 (8.6)
_
4”
_
40 (2.8) 125 (8.6)
_
5”
_
30 (2.1)
_ _
6”
_
25 (1.7)
_ _
Maximum Valve Body (Process Fluid) Temperatures
Two-way plug type valves 1/2” through 2” are rated for 410°F (210˚C).
Two-way plug type valves 21/2” through 6” bodies are rated to 350°(177˚C).
Three-way sleeve type valves (all sizes) are rated to 300° (148˚C).
Pressure Limits for Temperature Sensing Bulbs
The temperature sensing bulbs on a regulator are not recommended for direct insertion into any pressurized
system. The use of a Thermowell is strongly encouraged.
Brass and Steel Thermowells are rated to 500 PSIG (34.5 bar).
Stainless Steel Thermowells are rated to 1000 PSIG (68.9 bar).
Actuator Options 3
PRESSURE AND TEMPERATURE LIMITS
Maximum Static Pressure
Valve bodies in 1/2” through 2” sizes are rated for 250 PSIG (17.2 bar) max.
Valve bodies in 21/2” through 6” sizes are rated for 125 PSIG (8.6 bar) max.
Maximum Pressure Drop through the Valve
The “Pressure Drop” is the change in pressure of the process fluid as it passes through the valve.
A self-operating temperature regulator is often used on installations that at times will require a full shut
off, causing the pressure drop to equal the total inlet pressure. Therefore the inlet pressure should not
exceed the maximum pressure drops as listed in the following table.
Series 38R ••• Self-Acting Temperature Control Valves
Operation, Installation & Maintenance Manual
Page 5
INSTALLATION
Deciding the LOCATION for the Regulator
The regulator should be installed in an accessible location on horizontal piping. Possible damage from moving
parts, splashing of corrosive liquids, vibration, heat, fluid pulsations, etc., should be considered in deciding the
location. Similar consideration should also be given to the connecting tubing and bulb.
REGULATOR Installation
A strainer should be installed just ahead of the regulator to protect the valve from dirt, scale or foreign
matter which could interfere with the seating of the valve. A three valve by-pass installed around the
regulator will facilitate removal for service.
Blow out all pipe lines thoroughly to eliminate all foreign material from the system. Pipe thread compound
should be applied only on external or male pipe threads (not on the union nut threads). Install the regulator
in a vertical position with the flow direction through the valve corresponding to the flow arrow cast on the
valve body. Tighten tailpieces of unions on piping first and then tighten both valve union nuts
simultaneously.
Positioning the Indicator
The Option 2 Actuator contains an integral dial thermometer that can be rotated 330°
about the vertical axis for best readability. To prevent thermal system damage, a rotation stop is built in.
If the stop prevents a proper viewing angle from being achieved, rotate the thermometer in the opposite
direction. This thermometer can also be tilted up or down for maximum readability. To tilt, loosen the
clevis screw/nut, tilt thermometer to desired angle and re-tighten the clevis screw/nut combination.
NOTE: ACTUAL BYPASS
LINE SHOULD BE LEVEL
WITH OR ABOVE
PROCESS LINE.
Option 2
Self-Operating
Regulator
Strainer
STEAM INLET
Manual Valve
OPEN During
NORMAL Operation
Manual Valve
OPEN During
NORMAL Operation
TO PROCESS
Manual Valve
CLOSED During
NORMAL Operation
Series 38R ••• Self-Acting Temperature Control Valves
Operation, Installation & Maintenance Manual
Page 6
SENSING BULB
SENSING BULB LOCATION
The location of the sensing bulb is important. Use of a thermowell is always recommended, especially in
pressurized systems. The bulb or thermowell must be totally immersed in an average temperature location
which is representative of the whole volume being controlled. It should not be situated near hot or cold spots,
nor near the outlet of the valve supplying the heated or chilled fluid. If the regulator is to control a corrosive
fluid the bulb or thermowell must be constructed of a compatible material. Never install the bulb with the dead
end up unless it has been specifically ordered from, and constructed by, the factory for this service.
When installed in a pipeline, continuous flow past the sensing bulb must be maintained to obtain continuous
temperature signal to the regulator. If the flow stops, the pipeline may cool or warm to local room temperature
causing false reactions from the regulating valve. On some systems this may require a small by-pass flow line
around the valve to maintain representative system temperatures at the sensing bulb.
SENSING BULB INSTALLATION
To install a union connected sensing bulb, remove the union hub or thermowell from the sensing bulb and install
this hub or thermowell into the process piping or tank. If using a thermowell, liberally coat the sensing bulb with
the heat transfer paste supplied with the thermowell. Now slip the sensing bulb through the hub or into the well
until fully seated. Tighten the coupling nut. Do not over tighten.
Never attempt to tighten, loosen or otherwise rotate the hub or thermowell with the sensing bulb installed.
Always loosen the coupling nut before rotating the hub or thermowell. This will prevent twisting and kinking of
the connecting tubing thus preventing premature failure.
Keep all bends in the tubing greater than 11/2” radius. Do not subject the tubing to repeated flexing, vibration,
heat, cutting, kinking or other abuse. Coil all excess tubing and place in a cool location. If motion or vibration
may occur, secure the tubing to the bulb mounting so all moves as one. If vibration or fluid pulsations may be
transmitted to the bulb, it must be housed in a thermowell for protection from fatigue.
Series 38R ••• Self-Acting Temperature Control Valves
Operation, Installation & Maintenance Manual
Page 7
Using the supplied 1/4” rod, turn the 13/4” adjusting screw to a position on the “0 to 8” reference scale to a
position that approximately corresponds to the relative position of the desired control point within the adjustable
range. The “V” slot in the adjusting screw is intended as the index line for recording the setting number in
maintenance logs. To raise the control point, turn the adjusting screw from left to right up toward “HIGH”
marked on the reference scale. To lower the control point, turn the adjusting screw from right to left down
toward “LOW” marked on the reference scale. This adjustment must be done at system operating
pressure to balance the stem thrust load for proper regulation.
DO NOT TURN THE SMALL HEX STEM JAM NUTS.
THIS IS A CRITICAL SETTING FOR THE PROPER SEATING & STROKE OF THE REGULATOR.
PLACING THE REGULATOR INTO OPERATION AND SETTING THE CONTROL POINT
Figure 1: (Actuator Option 1 shown)
CAUTION:
DO NOT TURN THE ADJUSTING
SCREW BELOW THE “0” MARK
When the downstream units are ready to receive flow, close the by-pass valve and open all upstream
supply valves slowly to allow gradual start-up.
Observe the controlled temperature after it stabilizes and re-adjust the adjusting screw as required to obtain
the desired control point. Initial over shooting may occur until the system approaches equilibrium. Allow
sufficient time for correction to take place after each adjustment before further changing the setting.
Be certain that all manual valves in the main flow line are fully open and not restricting the flow.
Also be sure all downstream units are passing the flow properly.
Actuator
Reference Scale
1/4” Adjusting Rod
Valve Body Assembly
Adjusting Screw
Jam Nuts
Thermowell
Sensing Bulb
Series 38R ••• Self-Acting Temperature Control Valves
Operation, Installation & Maintenance Manual
Page 8
ROUTINE SERVICE
Since this instrument is self-contained and practically trouble free, very little maintenance is required. It is
important to keep the stem clean and free of deposits where it passes through the stem seals at the bonnet.
An occasional drop of oil on the stem will aid in eliminating mineral deposits and maintaining a free running
stem for accurate regulation. See Figure.
Figure 2
Removing any sharp mineral crystals from the stem will also reduce the chance of cutting the seal
lips and will prolong the seal life.
The packing seal is self-adjusting.
Do Not Tighten the packing nut beyond finger tight.
Leakage should never be tolerated. Any leak at bonnets, unions, plugs, etc., requires immediate
correction to avoid erosive action and serious damage or personal injury.
Loading...