Page 1
INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)
MODEL DA2
DIRECT-ACTING, POSITIVE BIAS DIFFERENTIAL
PRESSURE REDUCING REGULATOR
SECTION I
I. DESCRIPTION AND SCOPE
The Model DA2 is a differential pressure reducing regulator used to control differential pressure between downstream (outlet or P2) pressure and a loading (PLoad) pressure to the spring chamber. Sizes 1/2" (DN15), 3/4"
(DN20), 1" (DN25), 1-1/4" (DN32), 1-1/2" (DN40), 2" (DN50), 2-1/2" (DN65), 3" (DN80) and 4" (DN100). With
proper trim uti li za tion, the unit is suitable for liquid, gaseous, or steam service. Refer to Technical Bulletin DA2TB for design conditions and selection recommendations.
SECTION II
II. REFERENCES
ABBREVIATIONS
IOM-DA2
11-13
Refer to Technical Bulletin DA2-TB and DAG-TB for
tech ni cal specifi cations.
SECTION III
III. INSTALLATION
1. Regulator may be rotated around pipe axis 360
degrees. For ease of maintenance, the recommended position is with the spring chamber (4)
upwards. In liquid service it is recommended that
the spring cham ber (4) be oriented downwards,
and that a cus tom er supplied and installed vent
valve be pro vid ed at the external sensing con nec tion to bleed-off trapped gas/air under the
di a phragm.
2. Provide space below, above, and around reg u la tor for removal of parts during maintenance.
3. Install block valves and pressure gauges to provide means for adjustment, operation, bypass,
or removal of the regulator. An isolation valve
on the loading line is not rec om mend ed.
4. An outlet pressure gauge should be located ap prox i mate ly ten pipe diameters downstream, and
within sight. A loading pressure (or differential
pressure) gauge is rec om mend ed.
5. All installations should include a downstream
re lief device if the inlet pressure could exceed
the pressure rating of any downstream equipment or the maximum outlet pressure rating of
the unit.
CCW – Counter Clockwise
CW – Clockwise
ITA – Inner Trim Assembly
6. Clean the piping of all foreign material including
chips, welding scale, oil, grease and dirt before
in stall ing the regulator. Strainers are rec om mend ed.
7. In placing thread sealant on pipe ends prior to
en gage ment, ensure that excess material is
re moved and not allowed to enter the regulator
upon startup.
8. Flow Direction: Install so the fl ow direction
match es the arrow cast on the body.
9. If the loading pressure is not lowered suffi ciently
prior to shutting off the process fl uid supply,
then the diaphragm will be damaged with the
standard construction. The startup, shutdown,
and emergency operating procedures should be
reviewed to ensure that the loading pressure is
less than 50% of the Diaphragm Proof Rating
(See Table 1) before shutting off the process fl uid
supply pressure. If the regulator is specifi ed with
a fully supported diaphragm, then the diaphragm
will withstand a loading pressure equal to the
Diaphragm Proof Rating for the fully supported
diaphragm.
Page 2
PI
SRV
Outlet
@ P
2
Supply
@ P
1
(Shaded portion for steam/condensate systems)
Model 1000HP-1+6
Diffe re ntial
Bypass
Blowdown-Drain Blowdown-Drain
PI
10. Downstream Sensing Installation Considerations
– Internal or External Sensing:
a. The regulator may be installed with internal or
external sensing. Unless otherwise specifi ed,
the regulator is supplied by factory with internal
sensing. The regulator may be con vert ed in
the fi eld to external sensing (see Section VII
Maintenance, Paragraph H).
b. Reference DAG-TB, Table DAG-11 for rec-
ommendations for applying external pressure
sensing.
c. For internal sensing, no external line is re-
quired. For external sensing, use an external
control line. The line is connected from the port
(1/4" NPT) on the side of the body di a phragm
fl ange (see port 5 in Fig. 5) to a pressure tap.
The pressure tap should be located a minimum
of 10 pipe diameters downstream of the regulator. It is recommended that the downstream
pressure tap be located close to the point of
use to minimize the adverse affect of variable
line losses. A tubing outer diameter of 0.25
inch is adequate for short sensing lines (less
than 4 feet). Use 3/8" tubing or 1/4" Sch 40
pipe for sensing lines of 5 to 50 feet.
d. For condensable vapors (i.e. steam) slope the
external sensing line downward 2 to 5 de grees
to outlet piping to prevent water pock ets, which
allows the diaphragm chamber to always be
self draining. The external sensing line may
be sloped upward for liquids or gases.
CAUTION B
Installation of adequate overpressure pro tec tion
is recommended to pro tect the reg u la tor from
over pres sure and all down stream equip ment
from dam age in the event of regulator failure.
A hydrostatic or pneumatic proof test is allowable under the following conditions for the standard diaphragm
construction: Uniformly pressurize the valve body inlet,
valve body outlet, and loading chamber to the lesser
of the Diaphragm Proof Rating or 1.5 times the Outlet
Pressure Rating shown on the nameplate. For example, a 1" DA2 with Cast Iron Body and Spring Chamber,
Neoprene Diaphragm (BC) has an Outlet Pressure Rating of 400 psig CWP. The lesser pressure of 1.5X 400
psig = 600 psig and the BC diaphragm proof rating of
1250 psig is 600 psig. Therefore, uniformly pressurizing the DA2 to 600 psig is allowable.
Model DA2 & DA7 Differential
Pressure Reducing Regulator
CAUTION A
The proof test pressure must not exceed the
diaphragm and body rating for the regulator.
MAXIMUM DIAPHRAGM RATING *
NOTE: The below ratings may be further "derated" by limitations thru the Pressure Equipment Directive (97/23/EC-May '97).
BODY SIZE 1/2" - 2" (DN15-50) BODY SIZE 3" - 4" (DN80-100)
STD DIAPHRAGM
CONSTRUCTION
MAX P2 MAX P2 MAX
P
2
1250
(86.1)
450
(31.0)
700
(48.2)
125
(8.6)
1500
(103)
2
DIAPHRAGM
MATERIAL
BC, EPR
NBR
FKM, FKM+TFE, FK
3-ply (PTFE+FKM+PTFE)
METAL
Be-Cu
*Maximum setting of pressure safety device – safety relief valve or rupture disc.
**Not available for CI/CI, BRZ/CI, BRZ/BRZ, BRZ/CS, BRZ/SST, CS/CI & SST/CI constructions.
NA = NOT AVAILABLE
Recommended Piping Schematic for
Differential Pressure Reducing Station
TABLE 1
- psig (Barg)
**OPT-81 FULL DIAPHRAGM
SUPPORT
1250
(86.1)
1250
(86.1)
1250
(86.1)
125
(8.6)
NA NA
STD DIAPHRAGM
CONSTRUCTION
800
(55.1)
300
(20.6)
550
(37.9)
125
(8.6)
IOM-DA2
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IV. PRINCIPLE OF OPERATION
SECTION IV
1. Valve plug movements modulate the fl ow across
the valve seat to maintain the outlet pressure
2) equal to the sum of the differential pressure
(P
(∆PDIFF) and the loading pressure (PLoad). The
outlet pressure acting on the underside of the
diaphragm tends to close the valve plug against
the valve seat. The outlet pressure acting on the
topside of the diaphragm tends to lift the valve
plug off the valve seat. The positive differential
setting of the range spring tends to lift the valve
plug off the valve seat. The outlet pressure tracks
V. STARTUP
1. Start with the block valves closed.
2. Relax the range spring by turning the ad just ing
screw CCW for the DA2 (viewed from above) a
minimum of three (3) full rev o lu tions. This reduces
the ∆P
DIFF (differential) pres sure set point.
3. If it is a “hot” piping system, and equipped with
a bypass valve, partially open the bypass valve
to pre heat the system piping and to allow slow
ex pan sion of the piping. Check for proper steam
trap operation if installed. Closely monitor outlet
(down stream) pressure via gauge to ensure not
over-pres sur iz ing. NOTE: If no bypass valve is
in stalled, extra caution should be used in starting
up a cold system; (i.e. do everything slowly).
4. Crack open the outlet (downstream) block
valve.
2. For a DA2 (single diaphragm) design, a com plete
SECTION V
7. Continue to slowly open the outlet (downstream)
8. When fl ow is established steady enough that the
9. Set the DA2 regulator set point (∆P
with changes to the loading pressure. Each one
psi increase or decrease in the loading pressure
produces a respective one psi increase or decrease
in the outlet pressure.
diaphragm failure will cause the outlet process
fl uid to mix with the loading fl uid.
block valve, especially when the downstream
piping system is not pressurized. If the outlet
(down stream) pressure exceeds the desired
pres sure, close the inlet block valve and go to
Step 2. Close bypass valve approximately 25%,
and re peat pro ce dure.
outlet (downstream) block valve is fully open, begin
to slowly close the bypass valve if installed.
DIFF) by turning
the ad just ing screw clockwise (CW) to increase
outlet pres sure or CCW to reduce outlet pressure. The outlet (P
2) pressure under these con-
ditions will approximate the desired dif fer en tial
pressure when loaded with PLoad for the DA2.
CAUTION C
Do not walk away and leave a bypassed reg u la tor
unattended!
5. Slowly open the inlet (upstream) block valve to
about 25% open, observing the outlet (down stream) pres sure gauge. Determine if the reg u la tor
is fl owing. If not, slowly rotate the DA2 regulator
ad just ing screw CW (viewed from above) until
fl ow begins. Slightly open the bleeder valve to
vent any air as the spring chamber is fi lling with
a liquid loading fl uid.
6. Continue to slowly open the inlet (upstream) block
valve until fully open.
IOM-DA2
10. Pressurize the source of loading (P
Load) pres sure
and allow to fi ll the spring chamber cavity. Slightly
open the bleeder valve to vent any air as the
spring chamber is fi lling with a liquid loading fl uid.
11. Develop system fl ow and pressure and readjust
set point as required to obtain desired response.
Per for mance should be analyzed at minimum and
maximum fl ow levels.
12. Install closing cap where applicable. The standard
regulator relies on a double o-ring rotary seal (item
34) around the non-rising adjusting screw.
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VI. SHUTDOWN
SECTION VI
CAUTION D
Loading Pressure should be lowered as described
in Section III, paragraph 9 before shutting down the
system pressure.
1. To prevent force imbalances and possible di a phragm failure of the standard diaphragm construction, the loading pressure (PLoad) should be
lowered until the loading pressure (P
Load) is less
than 50% of the diaphragm proof rating for the
SECTION VII
VII. MAINTENANCE
A. General:
1. The regulator may be serviced without
re mov ing the regulator from pipeline. The
regulator is designed with quick-change trim
to simplify maintenance.
2. Record the nameplate information to
requisition spare parts for the regulator. The
in for ma tion should include: Size, KM Product
Code and Serial Number.
3. Refer to Section VIII for recommended spare
parts. Only use original equipment parts sup plied by Cashco/KM for re build ing or re pair ing
regulators.
4. Owner should refer to owner's procedures for
removal, handling, cleaning and disposal of
nonreuseable parts, i.e. gaskets, etc.
NOTE: On regulators originally suplied as Spe-
cial Cleaning Option-55, -56, or -57, maintenance must include a level of cleanliness equal
to Cashco cleaning standards of #S-1134,
#S-1542, and #S-1589 respectively. Con tact
factory for details.
5. The Inner Trim is re moved and replaced in the
body ( 23) as an assemblage of parts. The
Inner Trim Assembly, here in af ter called ITA,
consists of the following parts depending on
what dynamic sealing system the regulator is
using:
standard construction. System se quenc ing
must ensure this oc curs.
2. It is recommended that manual operation not be
attempted by a bypass valve during a shutdown.
3. When the outlet pressure (P
2) has been lowered
to 5 - 10 psig, the inlet (upstream) block valve
may be closed. The inlet pressure (P1) should
then decay to zero psig before the outlet (downstream) block valve is closed.
Item Dynamic
No. Seal Type Part Description
13 ..................... All ..........................Guide Bearing/Piston
14 .....................All ............................... StaticStem Seal †
14.1 ............... All ................... Upper Static Stem Seal †
14.2 ............... All ...................Middle Static Stem Seal †
14.3 ............... All ................... Lower Static Stem Seal †
15 .....................All ................................Cage O-ring Seal
16 .................CW,PW .............................................. Wiper
17.1 ..............CW,PW ................................. Wiper Washer
17.2 ........... OR,CP,PR ........ Camber Adjusting Washer *
17.3 ................. UC ..................................... Seal Retainer
19 ..................... All ................................................... Cage
20 ..................... All ...........................................Valve Plug
21 ..................... All ............................................Seat Ring
27 .....................All ............................. Dynamic Side Seal
27.1 ........... CP,CW ................................. TFE Cap Seal
27.2 ...........CP, CW ............................. O-ring Energizer
27.3 .............. UC .......... U-Cup Seal w/Metal Energizer
27.4 .............. OR ....................................... O-Ring Seal
27.5............PR,PW.....
* Metal Diaphragm Only.
† Comp. Diaphragm Only.
Piston Ring Seal w/Metal Energizer
A detailed view of the dynamic side seal parts is
shown in Figure 1 on the next page.
WARNING 1
SYSTEM UNDER PRESSURE. Prior to per form ing
any maintenance, isolate the reg u la tor from the sys tem and relieve all pressure. Failure to do so could
result in personal injury.*
* Includes external sensing connection if applicable.
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IOM-DA2
Page 5
13
13
13
19
BODY
27.4
20
Type OR — O-Ring
Dynamic Seal
Piston Rings (2) w/Metal Energizer
19
27.2
19
27.1
27.5
20
Type CP— TFE Cap
Dynamic Seal
13
19
27.2
19
27.1
16
17.1
20
Type CW — TFE Cap
Dynamic Seal + Wiper
13
19
IOM-DA2
SECTION "A"
27.5
13
16
17.1
20
Type PW — PRA Dy nam ic
Seal + Wiper
Figure 1: Dynamic Side Seals
27.3
17.3
20
Type UC — U-Cup
Dynamic Seal
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B. Main Valve Disassembly:
1. Shut down the system in accordance with
Section VI.
2. Disconnect the external sensing line, if
installed.
3. The quick change trim allows for the disassembly of the regulator while installed in the
pipeline. Alternatively the maintenance can
be done in a shop area. NOTE: It is easier to
repair the regulator when mounted upright in
a horizontal pipe run compared to a vertical
pipe run or a regulator mounted with spring
facing down. The description hereafter will
assume shop disassembly.
4. Remove regulator body (23) from pipeline.
Place the regulator in a vise with the spring
chamber (4) upwards.
12. For composition diaphragm construction,
remove lower diaphragm pusher plate (10).
13. Evenly loosen the three cage cap screws (18)
in single revolution increments. If the reg u la tor
con tains a lower piston spring (22), the ITA
should rise as the cage cap screws (18) are
evenly backed out. A downwards holding force
should be ap plied to the top of the piston-guide
bearing (13) to pre vent the ITA from pop ping
up as the last threads of the cage cap screws
(18) are backed out.
14. Remove the ITA by pulling up on the valve
plug (20). Set ITA aside.
15. Remove the lower piston spring (22), as
applicable, from within the body (23). NOTE:
Com po si tion diaphragm constructions do not
nor mal ly include a lower piston spring (22); all
metal diaphragm constructions MUST in clude
a lower piston spring (22).
5. Relax range spring (6) forces by turning adjusting screw (1) CCW (viewed from above)
until spring relaxes. The easiest way to check
this, is to carefully loosen the locknut (item
2). If the adjusting screw (item 1) sinks into
the chamber as the locknuts are loosened,
then the spring assembly is still in extension.
Turn the adjusting screw CW to remove the
extension. Fully remove the locknuts.
6. Loosen the diaphragm fl ange bolts (11) and
nuts (12) uniformly.
7. Place match marks on body (23) and spring
chamber (4) fl anges. Remove the spring
chamber (4).
8. Remove spring follower (5) and range
spring (6.1).
9. For composition diaphragm construction, hold
the milled “fl ats” on top of the valve plug (20)
stationary with appropriate socket wrench.
Loosen and remove the diaphragm lock nut
(7). NOTE: Metal diaphragm constructions
do NOT have a diaphragm lock nut (7).
10. Remove upper diaphragm pressure plate (8).
11. Remove diaphragm(s) (9, 9.1, 9.2, 9.9) and
o-ring upper stem seal (14.1). Examine
diaphragm(s) to determine whether failed; determine if op er at ing conditions are exceeding
pressure, pressure drop or temperature limits.
16. Remove o-ring cage seal (15).
17. Remove body (23) from vise. Clean all
reusable metal parts according to owner's
pro ce dures. (See Article VII.A.4. comments
concerning cleaning for ox y gen service.)
20
14.2
14.3
13
27
15
16
17
19
21
20
Figure 2: Assembled ITA,
Composition Di a phragm Construction
C. Disassembly of the ITA:
1. Removal of piston-guide bearing (13).
a. For a regulator with a composition
diaphragm(s) (see fi gure 2); pull the
valve plug (20) downwards and out
the piston-guide bearing (13) and out
of the lower end of the cage (19). Remove the piston-guide bearing (13)
from the upper end of the cage (19).
b. For a regulator with a metal diaphragm(s)
(see fi gure 3); hold the lower part of the
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IOM-DA2
Page 7
valve plug (20) in a bench vise, grasping
the milled fl ats directly under the seat disc
section of the plug (20). DO NOT clamp
the machined lower spindle area of the
plug (20) in the vise. The lower spindle
area must slide smoothly in the lower
guide bushing (24), therefore it cannot be
marred. Loosen the piston-guide bearing
(13) by turning CCW. A double-posted
spanner wrench should be used to allow
for easy loosening and correct reassembly
(see Double-Posted Spanner Wrench in
Section IX). Remove the valve plug from
the vise and complete the unthreading
of the valve plug from the piston-guide
bearing. Remove the valve plug from the
lower end of the cage (19) and remove
the piston-guide bearing from the upper
end of the cage.
"Flats"
Figure 3: Assembled ITA,
Metal Diaphragm Construction
D. Inspection of Parts:
1. After inspection remove from the work area
and dis card the old “soft goods” parts (i.e.
o-rings, di a phragms, seals, gaskets, etc.).
These parts MUST be re placed with fac to ry
supplied new parts.
13
27
15
17
19
21
20
2. Examine the com po nents (27.1, 27.2, 27.3,
27.4, 27.5) of the dy nam ic side seal (27)
mechanism to de ter mine if signifi cant leakage
was oc cur ring. If the dy nam ic side seal (27)
shows signs of sig nifi cant leakage, de ter mine
if op er at ing con di tions are ex ceed ing pres sure,
pressure drop, or tem per a ture limits.
Remove dynamic side seal (27) components.
Special care should be tak en when using
“tools” to remove the components to ensure
that no scratches are imparted to any portion
of the piston-guide bearing (13) groove.
3. Remove wiper seal (16), if supplied, from
within cage (19).
4. Remove wiper washer (17.1), camber adjusting washer (17.2), or seal retainer (17.3), if
sup plied, from within cage (19).
5. Remove o-ring lower stem seal (14.3) from
plug (20).
6. Remove seat ring (21); examine for signs
of leakage. If seat ring (21) shows signs of
signifi cant leakage, determine if op er at ing
con di tions of pressure, pres sure drop, or
temperature are ex ceed ing lim its.
7. Clean all reusable metal parts according to
owner's pro ce dures. NOTE: On regulators
originally supplied as Special Cleaning Option-55, -56, or -57, maintenance must include
a level of clean li ness equal to Cashco cleaning standards of #S-1134, #S-1542, #S-1589
re spec tive ly. Con tact factory for de tails.
2. Inspect the metal parts that will be reused. The
parts should be free of surface contaminants,
burrs, oxides, and scale. Rework and clean
the parts as necessary. Sur face con di tions that
affect the regulator per for mance are stated
below; replace parts that can not be re worked
or cleaned.
3. QC Requirements:
a. Valve plug (20);
1. 16 rms fi nish on its seating surface
for tight shutoff.
2. No major defects on bottom guide
spin dle.
b. Cage (19);
1. 16 rms fi nish on cylinder bore. No
“ledges” formed due to wear from
moving dynamic side seal (27) or
wiper seal (16).
c. Lower guide bushing (24) (non replaceable on 1/2" - 2" sizes):
1. 16 rms fi nish on bore.
2. Max 0.015 inch (0.38 mm) clearance
be tween valve plug (20) spindle and
lower guide bushing (24).
d. Internal sensing drilled plug (32);
1. Ensure that bore is minimum 0.125
inch (3.20 mm). Clean or drill out as
required.
4. Staging Material for Reassembly.
a. Inspect and clean parts, as necessary,
from the spare parts kit. (See Article
VII.A.4. comments concerning cleaning
for ox y gen service.)
b. Lay out all the regulator parts and check
against the bill of material.
IOM-DA2
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Page 8
E. Reassembly of the ITA:
1. When replacing the wiper seal (16), the wiper
seal (16) should be “performed” from the
factory. It will, however, require re form ing.
Reform the wiper seal (16) by press ing the
temporary assembly parts into the cage (19)
backwards as shown in Figure 4 (only applicable to composition diaphragm design).
The wiper seal (16) is best left in this position
overnight, but a min i mum of 30 minutes prior to
re as sem bly. Soaking in a bucket of hot water
will speed up the reforming process.
Not supplied. Use any
bolt, washers (2) and
nut of same approximate
hole size.
17
19
16
13
2. After reforming the wiper seal, remove parts
(13, 16, 17) from cage (19) and disassemble
the tem po rary assembly of Step 1. above.
3. Installation of dynamic side seal (27)
(See Figure 1):
a. Type OR:
1. Stretch o-ring seal (27.4) over lower
cir cum fer ence of piston-guide bearing (13), tak ing care not to “cut” o-ring
seal (27.4). Using thumbs, work the
o-ring seal (27.4) up and into the
groove of the piston-guide bearing
(13). NOTE: A very slight amount
of fl uid and elas tomer compatible
o-ring lubricant is rec om mend ed as
an installation aid.
2. For metal diaphragm construction, insert cam ber adjusting washer (17.2)
into cage (19) and allow to rest in the
bottom of the cage (19).
3. Position piston-guide bearing (13)
over upper end of cage (19) properly oriented. Using thumbs, evenly
press piston-guide bearing (13) into
the cage (19), ensuring not to “cut”
o-ring seal (27.4). Continue pressing
pis ton-guide bearing (13) until in approximate fi nal position.
b. Type CP:
1. Stretch o-ring energizer/seal (27.2)
over low er cir cum fer ence of pistonguide bear ing (13), tak ing care not
to “cut” o-ring energizer/seal (27.4).
Using thumbs, work the o-ring energizer/seal (27.4) up and into the
groove of the piston-guide bear ing
(13). NOTE: A very slight amount
of fl uid and elas tomer compatible
o-ring lubricant is rec om mend ed as
an installation aid.
Figure 4
2. For metal diaphragm construction,
insert cam ber adjusting washer
(17.2) into cage (19) and allow to
rest in the bottom of the cage (19).
3. Position TFE cap seal (27.1) ring
with rectangular cross-section at
end of pis ton-guide bearing (13).
Stretch cap seal (27.1) over lower
end of piston-guide bear ing (13)
using thumbs to work the cap
seal (27.1) onto the piston-guide
bearing (13). DO NOT USE A
TOOL FOR THIS STEP. Continue
pressing cap seal (27.1) up wards
towards the groove until the cap
seal (27.1) “snaps” into the groove
of the piston-guide bearing (13).
4. Position piston-guide bearing (13)
over and into upper end of cage
(19) until the cap seal (27.1) edge
touches the upper lip of the cage
(19). While gently applying force
to press the piston-guide bushing
(13) into the cage (19), simultaneously use fi ngers to lightly press
the cap seal (27.1) inwards into the
groove of the pis ton-guide bearing
(13) until the cap seal (27.1) “slips
into” the cage (19). DO NOT USE
TOOLS, LUBRICANT, OR HEAVY
FORCE TO EN GAGE THE CAP
SEAL (27.1) INTO THE CAGE
(19).
8
IOM-DA2
Page 9
IOM-DA2
c. Type CW:
1. Stretch o-ring energizer/seal (27.2)
over lower circumference of pistonguide bearing (13), taking care not
to “cut” o-ring energizer/seal (27.4).
Using thumbs, work the o-ring energizer/seal (27.4) up and into the
groove of the piston-guide bearing
(13). NOTE: A very slight amount
of fl uid and elastomer compatible
o-ring lubricant is recommended as
an installation aid.
2. Place wiper washer (17.1) into cage
(19). Allow wiper washer (17.1) to
rest on bottom of cage (19). Insert
wiper seal (16) into cage (19) at an
approximate 45° angled approach.
The turned-down lip of wiper seal (16)
entering cage (19) fi rst. Rotate wiper
seal (16) and wiper washer (17.1) to a
level position approximately half way
down into cage (19). The serrated
face of the wiper washer (17.1) must
contact the lower face of the wiper
seal (16) when the valve plug (20) is
inserted into the cage (19).
3. Position TFE cap seal (27.1) ring
with rectangular cross-section at
end of piston-guide bearing (13).
Stretch cap seal (27.1) over lower
end of piston-guide bearing (13) using
thumbs to work the cap seal (27.1)
onto the piston-guide bearing (13).
DO NOT USE A TOOL FOR THIS
STEP. Continue pressing cap seal
(27.1) upwards towards the groove
until the cap seal (27.1) “snaps” into
the groove of the piston-guide bearing
(13).
4. Position piston-guide bearing (13)
over and into upper end of cage (19)
until the cap seal (27.1) edge touches
the upper lip of the cage (19). While
gently applying force to press the
piston-guide bushing (13) into the
cage (19), simultaneously use fi ngers
to lightly press the cap seal (27.1)
inwards into the groove of the pistonguide bearing (13) until the cap seal
(27.1) “slips into” the cage (19). DO
NOT USE TOOLS, LUBRICANT, OR
HEAVY FORCE TO ENGAGE THE
CAP SEAL (27.1) INTO THE CAGE
(19).
d. Type PW:
1. Place wiper washer (17.1) into cage
(19). Allow wiper washer (17.1) to rest
on bottom of cage (19). Insert wiper seal
(16) into cage (19) at an approximate
45° angled approach. The turned-down
lip of wiper seal (16) entering cage (19)
fi rst. Rotate wiper seal (16) and wiper
washer (17.1) to a level position approximately half way down into cage
(19). The serrated face of the wiper
washer (17.1) must contact the lower
face of the wiper seal (16) when the
valve plug (20) is inserted into the cage
(19).
2. NOTE: Piston ring assy (27.5) consists
of one metal corrugated energizer and
two piston ring seals. Wrap corrugated
metal piston ring energizer into the
groove of piston-guide bearing (13).
3. Spread a piston ring seal and slide over
lower circumference of piston-guide
bearing (13). Using thumbs and fi n-
gers, work the piston ring seal into the
groove of the piston-guide bearing (13).
Repeat this procedure with a second
piston ring seal. Orient the Z-cuts in
the piston ring seals 180 degrees apart
to minimize leakage by the piston ring
assembly.
4. Position piston-guide bearing (13) over
and into upper end of cage (19) until
the lower piston ring seal touches the
upper lip of the cage (19). While gently
applying force to press the pistonguide bearing (13) into the cage (19),
simultaneously use fi ngers to lightly
circumferentially press the piston ring
assembly (27.5) inwards into the
piston-guide bearing (13) groove until
the piston ring assembly (27.5) “slips
into” the cage (19).
e. Type UC:
1. Insert seal retainer (17.3) into top of
cage and allow to rest in bottom of the
cage.
2. Position u-cup seal (27.3) over low er
circumference of piston-guide bearing (13). Ensure that the u-cup seal
(27.3) is oriented with the center-opendown wards as shown in Figure 1. The
u-cup seal (27.3) depends upon the
P1-Inlet Pres sure to activate the seal
for proper seal ing action.
9
Page 10
3. Position piston-guide bearing (13)
over and into upper end of cage (19)
until the cap seal (27.1) edge touches
the upper lip of the cage (19). While
gently applying force to press the
piston-guide bearing (13) into the
cage (19), simultaneously use fi ngers
to lightly press the u-cup seal (27.3)
inwards into the groove of the pistonguide bearing (13) until the u-cup seal
(27.3) “slips into” the cage (19). DO
NOT USE TOOLS, LUBRICANT, OR
HEAVY FORCE TO ENGAGE THE
U-CUP SEAL (27.3) INTO THE CAGE
(19).
F. Main Reassembly:
1. Place body (23) in a vise.
2. Reinstall internal sensing drilled plug (32) with
compatible thread sealant.
3. Insert the lower piston spring (22) into the
body (23), if supplied.
4. Fit the o-ring cage seal (15) into its body (23)
groove.
5. With the ITA held manually in the closed po si tion, insert ITA into body (23).
4. Place properly oriented seat ring (21) onto its
shoul der at the lower end of cage (19).
5. Composition Diaphragm Designs.
a. Place new o-ring lower stem seal (14.3)
into groove of valve plug (20).
b. Insert valve plug (20) upwards through
lower end of cage (19) and through the
center hole in piston-guide bearing (13),
also capturing camber adjusting washer
(17.2), wiper washer (17.1) and wiper seal
(16), if supplied. Hold plug (20) and cage
(19) together.
c. This completes ITA reassembly.
6. Metal Diaphragm Designs.
a. Insert valve plug (20) upwards through
lower end of cage (19) and through the
center hole of camber adjusting washer
(17.2) or wiper washer (17.1) and wiper
seal (16).
b. Engage valve plug (20) with piston-guide
bearing (13) threads and tighten manually
as far as possible.
c. Place ITA into a vise and grasp at a hub
location on the valve plug (20) that is not
in the “spindle” zone. (See Figure 3.)
d. Using a special double-posted spanner
wrench, (to order see NOTE in Sec tion
IX, Parts Ordering In for ma tion), tight en
the piston-guide bear ing (13) to the valve
plug (20) with the following torque values.
Do NOT allow valve plug (20) to rotate
against seat ring (21) during tight en ing.
Recommended Torque values are:
Body Size
in (DN)
1/2" - 1" (15-25)
1 1/4" - 2" (32-50)
Torque
ft-lbs (N-m)
30-50 (41-68)
45-70 (61-95)
6. Properly align all three cage bolt (18) holes
as there is only one circumferential location
pos si ble for this align ment. If a lower piston
spring (22) is used, apply downward force to
the top of the cage (19) until the ITA is lowered
suf fi cient ly to engage the cage bolts (18) into
the body (23). Engage all of the cage bolts
(18), then evenly screw in the cage bolts in
one-half revolution increments to pull down
the ITA, taking care NOT TO “COCK” THE ITA
IN THE BODY. Torque the cage bolts (18) to
13-15 ft-lbs (18-20 N-m).
7. Composition Diaphragm Designs:
a. For the following steps b.–h., the upper
end of valve plug (20) MUST be manually
held up if unit is not supplied with lower
piston spring (22).
b. Place new o-ring middle stem seal (14.2)
into groove of piston-guide bearing (13)
upper surface.
c. Position lower diaphragm pusher plate
(10) over upper end of valve plug (20)
with tongue and groove “groove” on up per
side.
d. Place new o-ring upper stem seal (14.1)
into groove on lower diaphragm pusher
plate (10).
e. Place diaphragm(s) (9) over end of valve
plug (20). NOTE: For multiple di a phragms
(9) that include TFE material, the TFE
should be on wetted side.
f. Place upper diaphragm pressure plate
(8) over upper end of valve plug (20) with
tongue and groove “ridge” on lower side.
g. Place anti-seize lubricant on valve plug
(20) thread ed end. Engage diaphragm
lock nut (7) with upper end of valve stem
(20) as far as possible manually.
h. Place a wrench on diaphragm lock nut (7)
and a torque wrench on the upper end
10
e. This completes ITA reassembly.
IOM-DA2
Page 11
of valve plug (20). Hold torque wrench
sta tion ary and rotate diaphragm lock nut
(7) to the following torque values:
Body Size
in (DN)
1/2" - 1" (15-25)
1 1/4" - 2" (32-50)
2 1/2" - 4" (65-100)
Torque
ft-lbs (N-m)
60-70 (81-95)
120-130 (163-176)
180-200 (244-271)
DO NOT allow valve plug (20) to rotate
against seat ring (21) during tightening.
i. This completes ITA reassembly.
8. Units with V-TFE & CTFE seat ring (21): Due
to the relative "hardness" of the V-TFE & CTFE
ma te ri al, to obtain the best possible shutoff it
is nec es sary to "coin" the V-TFE & CTFE with
a per ma nent in den ta tion.
a. Close-off the outlet connection.
b. The level of seat leakage can be quantifi ed
at the internal sens ing drilled plug (32) for
internal sensing units. For external sensing
units, it will be nec es sary to re move the
in ter nal sensing plug (33).
c. Pressurize the valve's inlet with gas or air
to 50 - 150 psig (3.5 - 10 Barg).
d. Using a soft-headed mallet (rubber,
leath er), sharply rap the top end of the
plug (20) for composition di a phragm designs, or the pis ton-guide bear ing (13) for
metal di a phragm designs. (NOTE: Gas
will escape as the plug (20) opens at the
seat ring (21). Allow suffi cient time for
leak age pressure on out let to bleed-off.)
The hammer rap should be strong enough
to "bounce" the plug (20) into the seat
ring (21), leaving the "coined" in den ta tion.
Check for leakage at the internal sensing port with a leak detection fl uid. One
bubble per second is typical of Class IV
shut off.
e. Repeat d. a minimum of 2 times until the
best possible seat leakage is ob tained.
f. After "coining" completed, remove gas
pressure source, remove outlet clo sure,
and re in stall plug (33) if removed.
9. Metal Diaphragm Designs:
a. Install new diaphragm gasket (37) onto
body (23) diaphragm fl ange.
b. Position diaphragm(s) (9) onto body's (23)
diaphragm fl ange.
c. Position upper diaphragm pressure plate
(8) onto center top of diaphragm(s)) (9)
with counterbore upwards.
10. Lubricate and install o-rings (34) into grooves
on the adjusting screw (1).
11. Assembly of range spring and spring chamber:
a. Lubricate the threads of adjusting screw
(1) then thread into the spring follower
(5).
The spring follower should be threaded
up adjusting the screw to within 3/8" of
the top threads (see sectional drawing,
fi gure 5.
b. Insert adjusting screw-spring follower into
spring chamber (4). NOTE: Milled slots in
spring follower must align with ribs in the
bore of the spring chamber. The top of
the adjusting screw must fi t in the center
hole of spring chamber. A light rap with
a wooden handle of a hammer may be
needed to fully install the adjusting screw
into the spring chamber.
c. Aligning match marks and bolt holes,
place spring chamber (4) over range
spring (6.1). If the spring chamber
fl ange reaches the body fl ange without
a gap, turn adjusting screw (1) CW 2-3
turns. Repeat this procedure until the
fl anges are approximately 1/8" apart. Be
sure that range spring is properly seated
into counterbore on spring follower.
NOTE: For metal diaphragm con struc tion,
if fl ang es do not come to geth er equal ly,
the upper di a phragm pres sure plate (8)
may be off-center. Remove spring cham ber (4) and reposition upper di a phragm
pres sure plate (8) until the spring chamber
(4) comes down evenly on all sides.
12. Reinstall all fl ange bolts (11) and nuts (12)
with nameplate (99) located under one bolt
head. Hand-tighten nuts (12).
NOTE: If a three-ply diaphragm is being used,
it is important that the diaphragm (9) is “pre formed” – allow formation of a diaphragm (9)
convolution. Starting with the body bolts and
nuts (11,12) hand tight ened, “preforming” can
be accomplished by any one of the following
techniques:
a. Relax range spring fully by rotating
ad just ing screw CCW.
b. Apply 30 psig (2.1 Barg) pressure to the
valve outlet.
OR
Block the valve outlet and apply 30 psig
(2.1 Barg) under the di a phragm through
the 1/4" NPT (plugged) external pres-
sure sens ing connection on the valve
diaphragm fl ange.
IOM-DA2
11
Page 12
c. Leave pressure on through tightening
of bolt ing (11,12).
13. Evenly tighten the body bolting (11,12) in an
alternating cross pattern in one revolution
increments to the following torque value:
Body Size
in (DN)
1/2" - 2" (15-50)
2 1/2" - 4" (65-100)
Torque
ft-lb (N-m)
30-35 (41-47)
45-50 (61-69)
If supplied, remove pressure of previous Step 12.
G. Units with Supported Diaphragm Designs:
1. A supported diaphragm (9) construction is
designated as Opt-81.
I. Pressure Testing:
1. Pressure Containment Test
(External Leak Test.).
a. See Section III, last paragraph and Table
1 for restrictions.
b. Spray leak detection solution over the
bolting, diaphragm edge, body, spring
chamber and all other pressure boundry
areas, during external leak test.
2. Inboard Leakage Test.
a. Release all range spring force by turning
adjusting screw CCW.
b. Pressurize inlet to 50 psig (3.5 Barg) with
air, GN
2.
c. Tube outlet to a beaker of water to ob-
serve number of escaping gas bubbles.
2. For a Model DA2 the only “special” part to be
supplied is the support plate (35) fi tted into
a counter bore cut into the body (23).
H. Converting Internal/External Sensing:
1. Disassemble the regulator and remove the
diaphragm(s) (9) according to Steps 1-12 in
Part B – Main Regulator Disassembly.
2. To convert from internal to external sensing,
remove the drilled pipe plug (32) and install
a solid pipe plug. Reverse this step for con vert ing from external to internal sensing.
3. Reassemble the regulator according to Part
F – Main Regulator Reassembly.
3. Excessive leakage will require disassembly,
examination of sealing elements, correction
of problem, reassembly and retesting. Leakage path may be via plug/seat or dynamic
side seal. Before disassemblying the regulator check the DAG-TB Table DAG-10 to
determine the acceptable inboard leak rates
of the seat and dynamic seal combination of
the regulator.
12
IOM-DA2
Page 13
SECTION VIII
VIII. TROUBLE SHOOTING GUIDE
When trouble shooting this regulator there are many possibilities as to what may be causing problems. Many times,
the regulator itself is not defective, but one or more of the accessories may be. Sometimes the pro cess may be
causing diffi culties.
The key to effi cient trouble shooting is information and communication. The customer should try to be as precise as
possible in their explanation of the problem, as well as their understanding of the application and operating
conditions.
It is imperative the following information be provided by the customer:
Fluid (with fl uid properties)
Range of fl ow rate
Range of inlet pressure
Range of outlet pressure
Range of fl uid temperature
Range of ambient temperature
Pressure readings should be taken at every location that pressure plays a role - i.e., regulator inlet (as close as
possible to inlet port), regulator outlet (as close as possible to outlet port), etc.
Below are some of the more common complaints along with possible causes and remedies.
1. Erratic regulation, instability or hunting.
Possible Causes Remedies
A. Sticking of internal parts A. Remove internals, clean and if necessary, replace.
B. Load changes are too quick for system B. Convert to external sensing (if necessary) and install an
orifi ce or needle valve in external sensing line.
C. Oversized regulator C. Check actual fl ow conditions; resize regulator for minimum
and maximum fl ow; if necessary, replace with smaller regulator.
D. Unstable loading pressure. D1. Stabilize loading pressure; i.e. pump, control valve, etc.
D2. Air in loading piping. Vent spring chamber.
2. Erratic regulation, instability or hunting (liquid service).
Possible Causes Remedies
A. Air trapped under diaphragm. A. Install valve on external sensing port and bleed off air.
(Install regulator upside down to help prevent reoccurrence.)
3. Downstream pressure will not reach desired setting.
Possible Causes Remedies
A. Supply pressure is down (conformation pressure gauge). A. Increase supply pressure.
B. Undersized regulator. B. Check actual fl ow conditions; resize regulator for minimum
and maximum fl ow; if necessary, replace with larger
regulator.
IOM-DA2
13
Page 14
4. Diaphragm continually breaks (steam service regulators).
Possible Causes Remedies
A. Stem seals (14) which protect fl uorocarbon elastomer in
diaphragm assembly may have deteriorated.
B. Diaphragm nut (7) may not be torqued to proper value. B. Confi rm torque value in accordance with Section VII, para-
C. Diaphragm too stiff causing it to crack in service.
A. Replace with new stem seals (14).
graph F-7.
C. Follow proper preforming and air evacuation techniques
during diaphragm installation in accordance with Section
VII, paragraph F-12.
5. Diaphragm continually breaks (all regulators).
Possible Causes Remedies
A. Differential pressure across diaphragm may have
exceeded limits. (See Table 1)
A. Be aware of limits as well as where the various pressures are
acting. Install pressure safety equipment as necessary.
6. Leakage at diaphragm fl ange.
Possible Causes Remedies
A. Body bolts not torqued properly.
B. Pressures at diaphragm may be too high for regulator
design.
A. Torque to proper value (see Section VII, paragraph F-13).
B. Consult factory.
7. Leakage across seat.
Possible Causes Remedies
A. Contamination (debris) in regulator. A1. Remove internals, clean and if necessary, replace sealing
and seating elements.*
A2. "Coin" seat if V-TFE or CTFE seat material.
B. Oversized regulator; valve plug operates directly next to
seat.
* Excess seat leakage may be diagnosed when a failure of the dynamic side seal has occurred. Inspect both potential
internal leak paths.
B. Check actual fl ow conditions; resize regulator for minimum
and maximum fl ow; if necessary, replace with smaller
regulator.
14
IOM-DA2
Page 15
SECTION IX
IX. ORDERING INFORMATION
NEW REPLACEMENT UNIT vs PARTS "KIT" FOR FIELD REPAIR
To obtain a quotation or place an order, please retrieve the Serial Number and Product Code that was stamped on
the metal name plate and attached to the unit. This information can also be found on the Bill of Material ("BOM"),
a parts list that was provided when unit was originally shipped. (Serial Number typically 6 digits). Product Code
typical format as follows: (last digit is alpha character that refl ects revision level for the product).
–
NEW REPLACEMENT UNIT:
Contact your local Cashco, Inc., Sales Rep re sen ta tive with the Serial Number and Product code.
With this information they can provide a quotation
for a new unit including a complete description,
price and availability.
CAUTION E
Do not attempt to alter the original construction
of any unit without assistance and approval from
the factory. All purposed changes will require a
new name plate with appropriate ratings and new
product code to accommodate the recommended
part(s) changes.
PARTS "KIT" for FIELD REPAIR:
Contact your local Cashco, Inc., Sales Rep re sen ta tive with the Serial Number and Product code.
Identify the parts and the quantity required to repair
the unit from the "BOM" sheet that was provided
when unit was originally shipped.
–
7
NOTE: In addition to ordering repair parts, it is
recommended that a special double-posted
spanner wrench fi tting be ordered for use
in the main te nance of the ITA. See the following table for correct size:
Double-Posted Spanner Wrench
Body Size
All A96-75-9-P0459-00
Part Number
NOTE: Those part numbers that have a quantity indicated
under "Spare Parts" in column "A” refl ect minimum
7
parts required for inspection and rebuild, - "Soft
Goods Kit". Those in column “B” include minimum
trim replacement parts needed plus those "Soft
Goods" parts from column "A".
If the "BOM" is not available, refer to the cross-
1
5
Figure 5: Location of Auxiliary Ports
2
sectional drawings included in this manual for part
identifi cation and selection.
A Local Sales Representative will provide quotation
for appropriate Kit Number, Price and Availability.
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. We reserve the right to
modify or improve the designs or specifi cations of such product at any time without notice.
Cashco, Inc. does not assume responsibility for the selection, use or maintenance of any product. Responsibility for proper selection, use and maintenance of any
Cashco, Inc. product remains solely with the purchaser.
IOM-DA2
15
Page 16
Figure 5
Composition Diaphragm
(w/Item 27.4 O-ring Seal)
Item No. Description
1 Adjusting Screw
3 Bleeder Valve Assembly
4 Spring Chamber
5 Spring Follower (Button)
6.1 Range Spring
7** Diaphragm Lock Nut
8 Upper Diaphragm Pressure Plate
9 Diaphragm
9.1 *** Diaphragm (Material #1)
9.2 *** Diaphragm (Material #2)
9.9 *** Diaphragm TFE Cover
10 ** Lower Diaphragm Pusher Plate
11 Flange Bolts
* 12 Flange Bolt Nuts
13 Piston-Guide Bearing
14 Stem Seals
14.1 Upper Stem Seal
14.2 Middle Stem Seal
14.3 Lower Stem Seal
15 Cage Seal
16 Wiper Seal
Cashco, Inc.
P.O. Box 6
Ellsworth, KS 67439-0006
PH (785) 472-4461
Fax. # (785) 472-3539
www.cashco.com
email: sales@cashco.com
Printed in U.S.A. DA2-IOM
Cashco GmbH
Handwerkerstrasse 15
15366 Hoppegarten, Germany
PH +49 3342 4243135
Fax. No. +49 3342 4243136
www.cashco.com
Email: germany@cashco.com
Item No. Description
17.1 Wiper Washer
18 Cage Cap Screws
19 Cage
20 Valve Plug
21 Seat Ring
22 Lower Piston Spring (if supplied)
23 Body
24 Lower Guide Bushing
26 Tap Plug (Not Shown)
27 ** Dynamic Side Seal
27.1 TFE Cap Seal
27.2 O-ring Energizer/Seal
27.3 U-cup with Metal Energizer
27.4 O-ring Seal
27.5 Piston Ring Seal w/Metal Energizer
32 Internal Sensing Plug (External Sensing Only)
33 Internal Sensing Drilled Plug (Internal Sensing Only)
34 Adjusting Screw O-ring
35 Support Plate (Not Shown)
* Not required on 2" CS & SST Body Material.
** Reference Figure 1 for details of Item #27 - Dynamic Side Seal.
*** Not utilized on metal diaphragm construction.
Cashco do Brasil, Ltda.
Al.Venus, 340
Indaiatuba - Sao Paulo, Brazil
PH +55 11 99677 7177
Fax. No.
www.cashco.com
Email: brazil@cashco.com
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