Armstrong OB 2000PT Manual

Model OB 2000PT
Pressure/Temperature Regulating Valve
Installation, Operation and Maintenance Instructions
This bulletin should be used by experienced personnel as a guide to the installation of the Model OB 2000PT Pressure/
Temperature RegulatingValve.Selectionorinstallationof equipmentshould alwaysbe accompaniedbycompetent
technical assistance.You are encouraged to contactArmstrong International, Inc. or its local sales representative for
additionalinformation.
1. AnArmstrong TVS Inverted Bucket SteamTrap is
recommended to drain condensate at the inlet of the
temperatureregulator.
2. AnArmstrong 100 mesh screen “Y” strainer should be
installedbefore thepressure/temperature regulator to
reducethe chance ofdirt fouling.
3. Apressure gaugeis recommendedbefore and after
thepressure/temperatureregulator.
4. If standard piping practice permits, a bypass line
aroundthe pressure/temperatureregulator is
recommended.The bypass line should runhorizontal
to the steam line.
5. The control pipe connects to a ¼” tapping on the side
of the pressure pilot valve. Be certain the control pipe
ispitched away from the pressure/temperature
regulator. Erratic control could result if this is not
done. The pipe should be installed a minimum of 10
outlet pipe diameters downstream of the last
obstruction.
Installation Instructions
Bulletin No. AY-731-A
Figure 1 -1. For Steam Service
By-Pass
Thermometer
Armstrong
Strainer
Armstrong
TVS Trap
2
Note:
1 Safety Relief Valve to be set at 10 psi higher or 10%
higher than the downstream pressure, whichever is greater.
2 It is suggested that the inlet "Y" type strainer be installed
on it's side to avoid the collection of liquid in the body that
could be carried through the regulator as a damaging slug
under certain conditions.
Swing Check Valve
(Vacuum Breaker)
1
Safety Relief
Valve
Armstrong
F&T Trap
Minimum of 20 Outlet
Pipe Diameters from
PRV to First Turn
Gate
Valve
OB 2000PT
Minimum of 10 Outlet
Pipe Diameters from
Last Valve or Fitting
Control Pipe
(Pitch Down)
Minimum of 10 Inlet
Pipe Diameters from
PRV to First Turn
Globe
Valve
6. Installthe pressure/temperatureregulator withthe
maindiaphragm housing down.Make sure the flow is
in the direction of the arrow on the body of the valve.
7. Avacuum breakershould be installed after theoutlet
of the heater coil and before the steam trap.
Automatic air vents should also be installed at all
pointswhere non-condensibles cancollect.
8. Avoidlifting condensate directly after steam traps.
Under light loads the pressure in the steam space is
reduced and often is too low to lift condensate.
Gravitydrain to return pump isrecommended, or pipe
ina safety draintrap. (See SteamConservation
Guidelines section in Bulletin 326).
Assembly & Installation
Thepressure/temperature regulatorwill come in two (2)
boxes. One box will contain an integral mount (pressure
pilotmounted onthe top of the mainvalve) mainvalve and
the second box containing the temperature pilot with
fittings which is not connected to the integral mounted
valve and the capillary system. Please read the instruction
bulletinbefore assembly andinstallation.

2
4. Do not twist or bend capillary sharply. Bending
radius of capillary should not be more than 1-1/2".
Position capillary so that it does not touch steam
lines, hot water lines, or regulator.
5. Install a thermometer into the fluid close to the
thermal bulb. See Figure 1-1 Page 1.
6. When using the thermal bulb (23) in a pipe, make
sure the thermal bulb is installed in a location
wherethe fluid freely flows aroundthe bulb.
7. If a thermal well is used. Make sure heat transfer
compoundis applied tothe thermal bulbbefore
installation into the well.
D. Regulating Method
Important: Temperaturecontrol is best achieved
when the delivery pressure is the lowest steam
pressurecapable ofmaintaining the desired
temperatureat maximum load.
1. Openvalve ondrip legto allowinverted bucket
steam trap to drain condensate on OB 2000PT
inlet.
A. Assembly
1. Donot losethe bellows follower(10), union
gasket(45) andpre-formed copper D pipe (46)as
shownin Figure2-2.
2. Insertcopper union gasket (45) intounion fitting,
tightenthe union jointand install pre-formed
copper D (46) pipe as shown in Figures 2-1
and2-2.
B. Installation of OB 2000PT Main Valve
1. Align flow direction with direction of arrow cast
into body.
2. InstallOB 2000PTperpendicular tohorizontal
piping so that the diaphragm chamber is located
at the bottom.
C. Installation of Capillary System
(See Figures 2-1, 2-2 and 4-1 on Page 4)
1. Once the valve body is installed, insert bellows
follower(10), which waspackaged with the
capillary system inside the sensor bellows (35)
with the flat side down toward the capillary
bellows.Turn the adjustingscrew (15)counter
clockwise to relieve spring tension.Attach
capillarysystem to temperaturepilot valve body
andtighten capillary ringunion (22).
SeeFigure 2-2.
2. Thermal Bulb (23) may be installed in any
position. However, care should be taken so that at
least three quarters of the thermal bulb is
touchingthe fluid being heated.
3. Screw in bushing (24) first and attach thermal
bulb (23) with packing nut (36). See Figure 4-1,
Page4.
Number on
Adjusting
Dial
18 - 59 50 - 97 86 - 144 131 - 201 176 - 260 239 - 361
12 39 72 113 154 214
1 28 59 99 142 192 266
2 43 77 120 169 225 307
3 57 93 136 196 257 352
4 70 109 153 223 297 410
0
Capillary System Range °F
Capillary Range
Table 2-1.
(45) Union
Gasket Copper
(28)
Lock
Nut Pressure
Pilot
"D" Pipe (46)
Lock
Nut
(16) OB-2000P
Pilot Valve
(30B) "B" Fitting
OB-2000
Main Valve
Capillary
Ring Union (22)
"C" Fitting (30C)
(Not Shown)
Te e
(33)
Bellows Follower (10)
Sensor Bellows (35)
Adjusting
Screw (27)
Adjusting
Screw (15)
H
H1
ØA
G
10-1/2"
(267 mm)
3/4" NPT
1" NPT
Thermal Well
9-1/2"
(241 mm)
Figure 2-1 OB 2000PT Figure 2-2

3
2. Closeinlet andoutlet valves toOB 2000PT and
open bypass line to clean the system. Be sure to
close bypass line after cleaning the system.
Duringblow down, make sure that the
temperature does not rise higher than the limit of
the capillary unit, otherwise damage to capillary
may occur.
3. Loosen lock nut (16) on the temperature pilot and
turnthe adjusting screw (15) and align the needle
withthe required temperatureposition on thedial.
See Table 2-1. Note that the number on the dial
willgive anapproximate temperature valuewith
thecorrespondingtemperature range.
4. Loosen lock nut (28) on the pressure pilot and
turnadjusting screw (27)counterclockwise
removingall tensionfrom adjustingspring (24).
5. Openvalve onoutlet ofOB 2000PT and also on
controlpipe.
6. Openinlet valveto OB2000PT– SLOWLY.
7. Turnthe adjustingscrew (27) onpressure pilot
valve clockwise until the heater output is 5°F
abovethe desiredtemperature setting.If
temperature adjustment in step 3 limits this
operation,adjust temperature pilot adjusting
screwaccordingly. Make sureall valvesbetween
theOB 2000PT and equipment areopen and
equipment is calling for steam.
8. Turnadjusting screw(15) ontemperature pilot
counterclockwise,lowering to thedesired
temperature.
9. Allow system to stabilize and adjust temperature
accordingly.
10. Tightenlock nut (16)on the temperaturepilot and
lock nut (28) on pressure pilot.
11. If adjustments are made at partial load the
temperaturewill sagunder heavierloads. When
maximum load occurs increase pressure setting
enoughto maintaindesired temperature.
Note: Make sure the set pressure temperature does
not exceed the temperature limit of the capillary.
Capillarycan withstand amaximum of 68°Fabove the
ratedrange.
Example –Capillary range of 131-201°F will
withstandtemperature of 269°F.
E. Maintenance Inspection
1. TroubleshootingHints –many of the problems
thatoccur withpressure/temperature regulators
aredue to dirtholding the mainor pilot valveopen.
Additionally make sure that the thermometer
sensingthe fluid temperatureis operating
correctly.
2. Check that the bellows follower was installed.
Disassembly
Before disassembly, make sure the inlet and outlet valves
to the regulator are closed and the pressure has been
relieved.
A. Disassembly of Temperature Pilot Valve
(See Figure 4-1 on Page 4)
1. Loosencapillary ringunion (22)and temperature
sensor bellows (35). Make sure not to lose
bellowsfollower(10).
2. Loosen lock nut (16) and turn adjusting screw (15)
counterclockwise (left), freeingup adjusting
spring(14).
3. Removefour hexagonalbolts (17)from the spring
housing(2) andremove adjustingspring (14).
4. Removetop bellowsplate (6) andtop seal bellows
(5).
5. Loosenthe guide(7) and remove the bottom
bellows plate (8) and the bottom bellows seal (5)
fromthe bottom halfof temperature pilot.
6. Removepilot valve andstem (3).
7. Forassembly procedure,followreverse order.
B. Disassembly of Pressure Pilot Valve
(See Figure 5-1 on Page 5)
1. Loosen the lock nut (28) and the adjusting
screw(27) counterclockwise (left)and turn
until the pressure is relieved from set point
adjustingspring (24).
2. Removefour hexhead bolts and take out
adjustingspring (24), bottom spring plate (26), top
springplate (25), andtwo pilot diaphragms (23).
3. Removepilot valveassembly (17,18, 19, 20,21)
at the center of the pilot body (2).
4. Pilotbody canbe removedfrom main valve by
disconnectingfitting (30A)and removingfour hex
bolts(38). Careshould be taken when removing
pilotfrom mainvalve. The main valve isheld bya
spring which is compressed.
C. Disassembly of Main Valve
(See Figure 5-1 on page 5)
1. Disconnect the copper tubing on the side of the
valve(See Fittings 30A, 30B, 30C).

4
Body (1)
Pilot Valve
Seat (4)
Pilot Valve
and Stem (3)
Pilot Spindle (28)
Gasket (19)
Guide (7)
Gasket (20)
Bottom Bellows
Seal (5)
Bottom Bellows
Plate (8)
Bellows Follower (10)
Sensor Bellows (35)
Capillary Ring Union (22)
Flexible Tube (27)
Capillary Tube (26)
Packing Nut (36) Bushing (24)
Bellows Guide (9)
Top Bellows Plate (6)
Thermal Bulb (23)
Gasket (20)
Top Bellows
Seal (5)
Spring Plate
Follower (9)
Bottom Spring
Plate (11)
Adjusting Spring (14)
Top Spring Plate (13)
Spring Housing (2)
Lock Washer (18)
Bolt (17)
Rivet (30)
Adjusting Screw (15)
Lock Nut (16)
Nameplate (29)
2. Removethe fourhex head bolts(38) from the pilot
body(2) to removethe pressure pilotfrom the
mainvalve body(1). Careshould betaken when
doingthis procedure. Themain valve isheld by a
spring (13) which is compressed. Once bodies
areapart, removespring plate (14), screen (15),
mainvalvespring (13)andmain valve(6).
3. UseaT-Barwrench toremove valveseat (7).
4. Removeall nutsand bolts(41) fromdiaphragm
case separating the top diaphragm case (4) and
thebottom diaphragm case(5), main diaphragms
(12),retainer (11) andmain spindle (9).
Assembly– Hints
1. Check to make sure there are not scratches on
the main valve or seat. If there are scratches,
applylapping compoundand relapvalve and seat.
2. Make sure all sliding parts (main spindle) move
freely.
3. Beforeassembling themain diaphragm(12),
makesure the mainvalve (6) issupported
correctlyby the mainvalve spring (13).
4. Confirmthat theretainer (11)and main spindle (9)
areconnected correctly.
5. * Make sure the main diaphragm case has
NeverSeize®applied and the surface thoroughly
cleanedbefore thediaphragms areinstalled.
Properperformance can notbe obtained in case
ofwrong thickness.
6. Tighten hex bolt and nuts uniformly.
Note: Repairkits areavailable fortemperature
pilotvalve, mainvalve, tubing,gaskets, liquid
gasketand diaphragms.
*Pleasenote that mostvalves will requireliquid
gasket for assembly on the main diaphragms.
OB 2000PT Pilot Valve Assembly
Figure 4-1
For Steam Service

5
Main Valve Seat (7)
Gasket (8)
Body (1)
Top Diaphragm
Case (4)
Fitting (30C)
Fitting (30B)
Pipe B (35)
Tee (33)
Plug (29)
Pipe D (46)
(pipe configuration
not exact)
Fitting (30A)
Pipe C (36)
Bolt (41)
Plug (49)
Elbow (32)
Nut (40)
Main Spindle (9)
E-Ring (53)
Retainer (11)
Main Diaphragms (12)
Bottom Diaphragm
Case (5)
Guide (10)
Stud Bolt (39)
Gasket (47)
Rivet (43)
Nameplate (42)
Bolt (37)
Bolt (38)
Gasket (22)
Pilot Body (2)
Gasket (16)
Screen (15)
Spring Plate (14)
Main Valve Spring (13)
a
Pilot Valve Seat Capsule (18)
Pilot Valve (17)
Plug (29)
Downstream
Sensing Port
Fitting (55)
Spring Housing (3)
Top Spring Plate (25)
Adjusting Spring (24)
Bottom Spring Plate (26)
Pilot Diaphragms (23)
Bolt (21)
Pilot Spring Plate (20)
Pilot Valve Spring (19)
Adjusting Screw (27)
Lock Nut (28)
a
Adapter Plate For
2" NPT - Does Not
Require Spring
Retainer (11)
Main Valve (6)
OB 2000PT Pressure/Temperature
Regulating Valve Integral Mount Pilot Assembly
Figure 5-1
For Steam Service

Armstrong-Yoshitake, Inc., 221 Armstrong Blvd., P.O. Box 408, Three Rivers, MI 49093 - USA Ph: [phone] Fax: [phone]
www.armstrong-intl.com
Bulletin No. AY-731-A 1/03 Printed in U.S.A.
Troubleshooting Guide
Problem Cause Solution
Improper adjustment. Re-adjust according to Regulating Methods
on Pages 2 and 3.
Faulty steam trap draining equipment. Check trap and correct problem.
Inadequate pressure to eliminate
condensate. Re-pipe system.
Bellows follower (10) was not installed. Install bellows follower.
No transfer medium applied to sensor. Apply heat transfer paste to thermal bulb
before installing in well.
Incorrect capillary range. Check label and change to correct range.
Improper adjustment.
Re-adjust according to Regulating Methods
on Pages 2 and 3.
Dirt or scale on main valve (6) and main
valve seat (7) or flawed valve and seat.
Disassemble and clean valve and seat, see
Page 3 for disassembly. In case of flawed
valve and seat replace them.
Dirt or scale on pilot valve and stem (3),
pilot valve seat (4).
Disassemble pilot and clean.
See Page 3 for disassembly.
Fitting orifice (30B) is blocked. Remove and clean.
Broken capillary system. Replace capillary system.
By-pass line leaks. Repair by-pass line.
Thermal bulb or thermometer are installed in
wrong location. See Page 1.
Relocate the thermal bulb so the fluid freely
flows around 3/4" of the bulb and/or relocate
the thermometer closer to the thermal bulb.
Inlet pressure too high. Lower inlet pressure. On low load
applications, the lower the inlet pressure,
the more stable the control will be.
Dirt or scale on pilot valve and stem (3),
guide (7) and pilot valve seat (4), main
spindle (9) is dirty. Disassemble and clean.
Body gasket leaks. Tighten bolts and replace gaskets
External leak.
Broken top bellows seal (5). Replace top bellows seal. Kit K-2611
Temperature Regulator
does not reach desired
set temperature.
Temperature rises
excessively.
Large variation
between thermometer
and temperature
regulator setting.