cashco DA2 Instruction manual

INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM) IOM-DA2
03-16
I. DESCRIPTION AND SCOPE
The Model DA2 is a differential pressure reducing regulator used to control differential pressure between down-
stream (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 utilization, the unit is suitable for liquid, gaseous, or steam service. Refer to Technical Bulletin DA2-
TB for design conditions and selection recommendations.
MODEL DA2
DIRECT-ACTING, POSITIVE BIAS DIFFERENTIAL
PRESSURE REDUCING REGULATOR
SECTION I
II. REFERENCES
Refer to Technical Bulletin DA2-TB and DAG-TB for
technical specifications.
ABBREVIATIONS
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
installing the regulator. Strainers are recom-
mended.
7. In placing thread sealant on pipe ends prior to
engagement, ensure that excess material is
removed and not allowed to enter the regulator
upon startup.
8. Flow Direction: Install so the flow direction
matches the arrow cast on the body.
9. If the loading pressure is not lowered sufficiently
prior to shutting off the process fluid 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 fluid
supply pressure. If the regulator is specified with
a fully supported diaphragm, then the diaphragm
will withstand a loading pressure equal to the
Diaphragm Proof Rating for the fully supported
diaphragm.
SECTION III
SECTION II
1. Regulator may be rotated around pipe axis 360
degrees. For ease of maintenance, the recom-
mended position is with the spring chamber (4)
upwards. In liquid service it is recommended that
the spring chamber (4) be oriented downwards,
and that a customer supplied and installed vent
valve be provided at the external sensing con-
nection to bleed-off trapped gas/air under the
diaphragm.
2. Provide space below, above, and around regula-
tor for removal of parts during maintenance.
3. Install block valves and pressure gauges to pro-
vide means for adjustment, operation, bypass,
or removal of the regulator. An isolation valve
on the loading line is not recommended.
4. An outlet pressure gauge should be located ap-
proximately ten pipe diameters downstream, and
within sight. A loading pressure (or differential
pressure) gauge is recommended.
5. All installations should include a downstream
relief device if the inlet pressure could exceed
the pressure rating of any downstream equip-
ment or the maximum outlet pressure rating of
the unit.
III. INSTALLATION
ISO Registered Company

IOM-DA2
2
10. Downstream Sensing Installation Considerations
– Internal or External Sensing:
a. The regulator may be installed with internal or
external sensing. Unless otherwise specified,
the regulator is supplied by factory with internal
sensing. The regulator may be converted in
the field to external sensing (see Section VII
Maintenance, Paragraph H).
b. Reference DAG-TB, Table DAG-11 for recom-
mendations 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 diaphragm
flange (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 regu-
lator. 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 degrees
to outlet piping to prevent water pockets, which
allows the diaphragm chamber to always be
self draining. The external sensing line may
be sloped upward for liquids or gases.
Recommended Piping Schematic for
Differential Pressure Reducing Station
CAUTION
The proof test pressure must not exceed the
diaphragm and body rating for the regulator.
CAUTION
Installation of adequate overpressure protection
is recommended to protect the regulator from
overpressure and all downstream equipment
from damage in the event of regulator failure.
Model DA2 & DA7 Differential
Pressure Reducing Regulator
A hydrostatic or pneumatic proof test is allowable un-
der 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 exam-
ple, a 1" DA2 with Cast Iron Body and Spring Chamber,
Neoprene Diaphragm (BC) has an Outlet Pressure Rat-
ing 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 pressur-
izing the DA2 to 600 psig is allowable.
TABLE 1
MAXIMUM DIAPHRAGM RATING * - psig (Barg)
*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
DIAPHRAGM
MATERIAL
BODY SIZE 1/2" - 2" (DN15-50) BODY SIZE 3" - 4" (DN80-100)
STD DIAPHRAGM
CONSTRUCTION
**OPT-81 FULL DIAPHRAGM
SUPPORT
STD DIAPHRAGM
CONSTRUCTION
P2MAX P2MAX P2MAX
BC, EPR 1250
(86.1)
1250
(86.1)
800
(55.1)
NBR 450
(31.0)
1250
(86.1)
300
(20.6)
FKM, FKM+TFE, FK 700
(48.2)
1250
(86.1)
550
(37.9)
3-ply (PTFE+FKM+PTFE) 125
(8.6)
125
(8.6)
125
(8.6)
METAL
Be-Cu
1500
(103) NA NA
NOTE: The below ratings may be further "derated" by limitations thru the Pressure Equipment Directive (97/23/EC-May '97).

IOM-DA2 3
IV. PRINCIPLE OF OPERATION
1. Valve plug movements modulate the flow across
the valve seat to maintain the outlet pressure
(P2) equal to the sum of the differential pressure
(∆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
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.
2. For a DA2 (single diaphragm) design, a complete
diaphragm failure will cause the outlet process
fluid to mix with the loading fluid.
SECTION V
V. STARTUP
1. Start with the block valves closed.
2. Relax the range spring by turning the adjusting
screw CCW for the DA2 (viewed from above) a
minimum of three (3) full revolutions. This reduces
the ∆PDIFF (differential) pressure set point.
3. If it is a “hot” piping system, and equipped with
a bypass valve, partially open the bypass valve
to preheat the system piping and to allow slow
expansion of the piping. Check for proper steam
trap operation if installed. Closely monitor outlet
(downstream) pressure via gauge to ensure not
over-pressurizing. NOTE: If no bypass valve is
installed, extra caution should be used in starting
up a cold system; (i.e. do everything slowly).
4. Crack open the outlet (downstream) block valve.
CAUTION
Do not walk away and leave a bypassed regulator
unattended!
5. Slowly open the inlet (upstream) block valve to
about 25% open, observing the outlet (down-
stream) pressure gauge. Determine if the regulator
is flowing. If not, slowly rotate the DA2 regulator
adjusting screw CW (viewed from above) until
flow begins. Slightly open the bleeder valve to
vent any air as the spring chamber is filling with
a liquid loading fluid.
6. Continue to slowly open the inlet (upstream) block
valve until fully open.
7. Continue to slowly open the outlet (downstream)
block valve, especially when the downstream
piping system is not pressurized. If the outlet
(downstream) pressure exceeds the desired pres-
sure, close the inlet block valve and go to Step
2. Close bypass valve approximately 25%, and
repeat procedure.
8. When flow is established steady enough that the
outlet (downstream) block valve is fully open, begin
to slowly close the bypass valve if installed.
9. Set the DA2 regulator set point (∆PDIFF) by turning
the adjusting screw clockwise (CW) to increase
outlet pressure or CCW to reduce outlet pres-
sure. The outlet (P2) pressure under these con-
ditions will approximate the desired differential
pressure when loaded with PLoad for the DA2.
10. Pressurize the source of loading (PLoad) pressure
and allow to fill the spring chamber cavity. Slightly
open the bleeder valve to vent any air as the
spring chamber is filling with a liquid loading fluid.
11. Develop system flow and pressure and readjust
setpoint as required to obtain desired response.
Performance should be analyzed at minimum and
maximum flow 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.
SECTION IV

IOM-DA2
4
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.....
Piston Ring Seal w/Metal Energizer
* Metal Diaphragm Only.
† Comp. Diaphragm Only.
SECTION VII
VII. MAINTENANCE
A. General:
1. The regulator may be serviced without remov-
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
information should include: Size, Product Code
and Serial Number.
3. Refer to Section VIII for recommended spare
parts. Only use original equipment parts sup-
plied by Cashco for rebuilding or repairing
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, mainte-
nance must include a level of cleanliness equal
to Cashco cleaning standards of #S-1134,
#S-1542, and #S-1589 respectively. Contact
factory for details.
5. The Inner Trim is removed and replaced in the
body ( 23) as an assemblage of parts. The
Inner Trim Assembly, hereinafter called ITA,
consists of the following parts depending on
what dynamic sealing system the regulator is
using:
A detailed view of the dynamic side seal parts is
shown in Figure 1 on the next page.
SECTION VI
VI. SHUTDOWN
1. To prevent force imbalances and possible dia-
phragm failure of the standard diaphragm con-
struction, the loading pressure (PLoad) should be
lowered until the loading pressure (PLoad) is less
than 50% of the diaphragm proof rating for the
standard construction. System sequencing
must ensure this occurs.
2. It is recommended that manual operation not be
attempted by a bypass valve during a shutdown.
3. When the outlet pressure (P2) 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 (down-
stream) block valve is closed.
CAUTION
Loading Pressure should be lowered as described
in Section III, paragraph 9 before shutting down the
system pressure.
WARNING
SYSTEM UNDER PRESSURE. Prior to performing
any maintenance, isolate the regulator from the
system and relieve all pressure. Failure to do so
could result in personal injury.*
* Includes external sensing connection if applicable.

IOM-DA2 5
Figure 1: Dynamic Side Seals
Type OR — O-Ring
Dynamic Seal
Type CW — TFE Cap
Dynamic Seal + Wiper
Type CP— TFE Cap
Dynamic Seal
Type PW — PRA Dynamic
Seal + Wiper
Type UC — U-Cup
Dynamic Seal
SECTION "A"
20
27.4
BODY
19
13 13
27.2
19
27.1
20
20
17.1
16
27.1
19
27.2
13
20
17.3
27.3
19
13
13
19
27.5
16
17.1
20
19
27.5
13
Piston Rings (2) w/Metal Energizer

IOM-DA2
6
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
regulator contains 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 applied to the top of
the piston-guide bearing (13) to prevent the
ITA from popping 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:
Composition diaphragm constructions do not
normally include a lower piston spring (22); all
metal diaphragm constructions MUST include
a lower piston spring (22).
16. Remove o-ring cage seal (15).
17. Remove body (23) from vise. Clean all
reusable metal parts according to owner's
procedures. (See Article VII.A.4. comments
concerning cleaning for oxygen service.)
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 disas-
sembly 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.
5. Relax range spring (6) forces by turning ad-
justing 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 flange bolts (11) and
nuts (12) uniformly.
7. Place match marks on body (23) and spring
chamber (4) flanges. Remove the spring
chamber (4).
8. Remove spring follower (5) and range
spring (6.1).
9. For composition diaphragm construction, hold
the milled “flats” 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; de-
termine if operating conditions are exceeding
pressure, pressure drop or temperature limits.
Figure 2: Assembled ITA,
Composition Diaphragm Construction
C. Disassembly of the ITA:
1. Removal of piston-guide bearing (13).
a. For a regulator with a composition
diaphragm(s) (see figure 2); pull the
valve plug (20) downwards and out
the piston-guide bearing (13) and out
of the lower end of the cage (19). Re-
move the piston-guide bearing (13)
from the upper end of the cage (19).
b. For a regulator with a metal diaphragm(s)
(see figure 3); hold the lower part of the
20
14.2 14.3
13
27
15
16
17
19
21
20

IOM-DA2 7
Figure 3: Assembled ITA,
Metal Diaphragm Construction
"Flats"
13
27
15
17
19
21
20
valve plug (20) in a bench vise, grasping
the milled flats 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.
2. Examine the components (27.1, 27.2, 27.3,
27.4, 27.5) of the dynamic side seal (27)
mechanism to determine if significant leakage
was occurring. If the dynamic side seal (27)
shows signs of significant leakage, determine
if operating conditions are exceeding pressure,
pressure drop, or temperature limits.
Remove dynamic side seal (27) components.
Special care should be taken 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 adjust-
ing washer (17.2), or seal retainer (17.3), if
supplied, 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
significant leakage, determine if operating
conditions of pressure, pressure drop, or
temperature are exceeding limits.
7. Clean all reusable metal parts according to
owner's procedures. NOTE: On regulators
originally supplied as Special Cleaning Op-
tion-55, -56, or -57, maintenance must include
a level of cleanliness equal to Cashco clean-
ing standards of #S-1134, #S-1542, #S-1589
respectively. Contact factory for details.
D. Inspection of Parts:
1. After inspection remove from the work area
and discard the old “soft goods” parts (i.e.
o-rings, diaphragms, seals, gaskets, etc.).
These parts MUST be replaced with factory
supplied new parts.
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. Surface conditions that
affect the regulator performance are stated
below; replace parts that can not be reworked
or cleaned.
3. QC Requirements:
a. Valve plug (20);
1. 16 rms finish on its seating surface
for tight shutoff.
2. No major defects on bottom guide
spindle.
b. Cage (19);
1. 16 rms finish 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 finish on bore.
2. Max 0.015 inch (0.38 mm) clearance
between 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 oxygen service.)
b. Lay out all the regulator parts and check
against the bill of material.

IOM-DA2
8
Figure 4
Not supplied. Use any
bolt, washers (2) and
nut of same approximate
hole size.
17
19
16
13
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 reforming.
Reform the wiper seal (16) by pressing the
temporary assembly parts into the cage (19)
backwards as shown in Figure 4 (only ap-
plicable to composition diaphragm design).
The wiper seal (16) is best left in this position
overnight, but a minimum of 30 minutes prior to
reassembly. Soaking in a bucket of hot water
will speed up the reforming process.
2. After reforming the wiper seal, remove parts
(13, 16, 17) from cage (19) and disassemble
the temporary 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
circumference of piston-guide bear-
ing (13), taking 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 fluid and elastomer compatible
o-ring lubricant is recommended as
an installation aid.
2. For metal diaphragm construction,
insert camber 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) prop-
erly oriented. Using thumbs, evenly
press piston-guide bearing (13) into
the cage (19), ensuring not to “cut”
o-ring seal (27.4). Continue pressing
piston-guide bearing (13) until in ap-
proximate final position.
b. Type CP:
1. Stretch o-ring energizer/seal (27.2)
over lower circumference of piston-
guide bearing (13), taking care not
to “cut” o-ring energizer/seal (27.4).
Using thumbs, work the o-ring en-
ergizer/seal (27.4) up and into the
groove of the piston-guide bearing
(13). NOTE: A very slight amount
of fluid and elastomer compatible
o-ring lubricant is recommended as
an installation aid.
2. For metal diaphragm construction,
insert camber 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 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), simultane-
ously use fingers to lightly press
the cap seal (27.1) inwards into the
groove of the piston-guide 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).

IOM-DA2 9
c. Type CW:
1. Stretch o-ring energizer/seal (27.2)
over lower circumference of piston-
guide bearing (13), taking care not to
“cut” o-ring energizer/seal (27.4). Us-
ing 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 fluid and elas-
tomer 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) first. 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 fingers
to lightly press the cap seal (27.1)
inwards into the groove of the piston-
guide 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)
first. Rotate wiper seal (16) and wiper
washer (17.1) to a level position ap-
proximately 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 fin-
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 piston-
guide bearing (13) into the cage (19),
simultaneously use fingers 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 lower
circumference of piston-guide bear-
ing (13). Ensure that the u-cup seal
(27.3) is oriented with the center-open-
downwards as shown in Figure 1. The
u-cup seal (27.3) depends upon the
P1-Inlet Pressure to activate the seal
for proper sealing action.

IOM-DA2
10
Recommended Torque values are:
Body Size Torque
in (DN) ft-lbs (N-m)
1/2" - 1" (15-25) 30-50 (41-68)
1 1/4" - 2" (32-50) 45-70 (61-95)
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 fingers
to lightly press the u-cup seal (27.3)
inwards into the groove of the piston-
guide 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) INTOTHECAGE
(19).
4. Place properly oriented seat ring (21) onto its
shoulder 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 Section
IX, Parts Ordering Information), tighten
the piston-guide bearing (13) to the valve
plug (20) with the following torque values.
Do NOT allow valve plug (20) to rotate
against seat ring (21) during tightening.
e. This completes ITA reassembly.
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 posi-
tion, insert ITA into body (23).
6. Properly align all three cage bolt (18) holes
as there is only one circumferential location
possible for this alignment. If a lower piston
spring (22) is used, apply downward force to
the top of the cage (19) until the ITA is lowered
sufficiently 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 upper
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 diaphragms
(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) threaded 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

IOM-DA2 11
Body Size
in (DN)
Torque
ft-lbs (N-m)
1/2" - 1" (15-25) 60-70 (81-95)
1 1/4" - 2" (32-50) 120-130 (163-176)
2 1/2" - 4" (65-100) 180-200 (244-271)
of valve plug (20). Hold torque wrench
stationary and rotate diaphragm lock nut
(7) to the following torque values:
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
material, to obtain the best possible shutoff it
is necessary to "coin" the V-TFE & CTFE with
a permanent indentation.
a. Close-off the outlet connection.
b. The level of seat leakage can be quantified
at the internal sensing drilled plug (32) for
internal sensing units. For external sensing
units, it will be necessary to remove the
internal 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,
leather), sharply rap the top end of the
plug (20) for composition diaphragm de-
signs, or the piston-guide bearing (13) for
metal diaphragm designs. (NOTE: Gas
will escape as the plug (20) opens at the
seat ring (21). Allow sufficient time for
leakage pressure on outlet to bleed-off.)
The hammer rap should be strong enough
to "bounce" the plug (20) into the seat
ring (21), leaving the "coined" indentation.
Check for leakage at the internal sensing
port with a leak detection fluid. 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 obtained.
f. After "coining" completed, remove gas
pressure source, remove outlet closure,
and reinstall plug (33) if removed.
9. Metal Diaphragm Designs:
a. Install new diaphragm gasket (37) onto
body (23) diaphragm flange.
b. Position diaphragm(s) (9) onto body's (23)
diaphragm flange.
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,
figure 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 fit 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
flange reaches the body flange without
a gap, turn adjusting screw (1) CW 2-3
turns. Repeat this procedure until the
flanges are approximately 1/8" apart.
Be sure that range spring is properly
seated into counterbore on spring follower.
NOTE: For metal diaphragm construction,
if flanges do not come together equally,
the upper diaphragm pressure plate (8)
may be off-center. Remove spring cham-
ber (4) and reposition upper diaphragm
pressure plate (8) until the spring chamber
(4) comes down evenly on all sides.
12. Reinstall all flange 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 tightened, “preforming” can
be accomplished by any one of the following
techniques:
a. Relax range spring fully by rotating
adjusting 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 diaphragm through
the 1/4" NPT (plugged) external pres-
sure sensing connection on the valve
diaphragm flange.
c. Leave pressure on through tightening
of bolting (11,12).

IOM-DA2
12
Body Size
in (DN)
Torque
ft-lb (N-m)
1/2" - 2" (15-50) 30-35 (41-47)
2 1/2" - 4" (65-100) 45-50 (61-69)
13. Evenly tighten the body bolting (11,12) in an
alternating cross pattern in one revolution
increments to the following torque value:
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.
2. For a Model DA2 the only “special” part to be
supplied is the support plate (35) fitted 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-
verting from external to internal sensing.
3. Reassemble the regulator according to Part
F – Main Regulator Reassembly.
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, GN2.
c. Tube outlet to a beaker of water to ob-
serve number of escaping gas bubbles.
3. Excessive leakage will require disassembly,
examination of sealing elements, correction
of problem, reassembly and retesting. Leak-
age path may be via plug/seat or dynamic
side seal. Before disassemblying the regu-
lator check the DAG-TB Table DAG-10 to
determine the acceptable inboard leak rates
of the seat and dynamic seal combination of
the regulator.

IOM-DA2 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 process may be
causing difficulties.
The key to efficient 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 fluid properties)
Range of flow rate
Range of inlet pressure
Range of outlet pressure
Range of fluid 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.
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
orifice or needle valve in external sensing line.
C. Oversized regulator C. Check actual flow conditions; resize regulator for minimum
and maximum flow; 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.
1. Erratic regulation, instability or hunting.
Possible Causes Remedies
A. Supply pressure is down (conformation pressure gauge). A. Increase supply pressure.
B. Undersized regulator. B. Check actual flow conditions; resize regulator for minimum
and maximum flow; if necessary, replace with larger
regulator.
3.Downstream pressure will not reach desired setting.
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.)
2. Erratic regulation, instability or hunting (liquid service).

IOM-DA2
14
4. Diaphragm continually breaks (steam service regulators).
Possible Causes Remedies
A. Stem seals (14) which protect fluorocarbon elastomer in
diaphragm assembly may have deteriorated. A. Replace with new stem seals (14).
B. Diaphragm nut (7) may not be torqued to proper value. B. Confirm torque value in accordance with Section VII, para-
graph F-7.
C. Diaphragm too stiff causing it to crack in service. 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 flange.
Possible Causes Remedies
A. Body bolts not torqued properly. A. Torque to proper value (see Section VII, paragraph F-13).
B. Pressures at diaphragm may be too high for regulator
design. 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.
B. Check actual flow conditions; resize regulator for minimum
and maximum flow; if necessary, replace with smaller
regulator.
* Excess seat leakage may be diagnosed when a failure of the dynamic side seal has occurred. Inspect both potential
internal leak paths.

IOM-DA2 15
SECTION IX
Figure 5: Location of Auxiliary Ports
2
1
7
5
Double-Posted Spanner Wrench
Body Size Part Number
All A96-75-9-P0459-00
NEW REPLACEMENT UNIT:
Contact your local Cashco, Inc., Sales Represen-
tative 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.
–7–
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 reflects revision level for the product).
PARTS "KIT" for FIELD REPAIR:
Contact your local Cashco, Inc., Sales Represen-
tative 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.
NOTE: Those part numbers that have a quantity indicated
under "Spare Parts" in column "A” reflect minimum
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-
sectional drawings included in this manual for part
identification and selection.
A Local Sales Representative will provide quotation
for appropriate Kit Number, Price and Availability.
CAUTION
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.
NOTE: In addition to ordering repair parts, it is
recommended that a special double-posted
spanner wrench fitting be ordered for use
in the maintenance of the ITA. See the fol-
lowing table for correct size:
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 specifications 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.

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
‡‡ Recommended Repair Parts
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.
Figure 5
Composition Diaphragm
(w/Item 27.4 O-ring Seal)
Cashco, Inc.
P.O. Box 6
Ellsworth, KS 67439-0006
PH [phone]
Fax. # [phone]
www.cashco.com
email: [email protected]
Printed in U.S.A. DA2-IOM
Cashco do Brasil, Ltda.
Al.Venus, 340
Indaiatuba - Sao Paulo, Brazil
PH [phone]
Fax. No.
www.cashco.com
email: [email protected]
Loading Connection
Cashco GmbH
Handwerkerstrasse 15
15366 Hoppegarten, Germany
PH [phone]
Fax. No. [phone]
www.cashco.com
email: [email protected]