cashco DA5 Instruction manual

INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM) IOM-DA5
03/16
I. DESCRIPTION AND SCOPE
The Model DA5 is a spring operated back pressure regulator used to control upstream (inlet or P1) pressure. Sizes
are 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. The Model DA5
is available in a more common “reverse” flow direction arrangement, that is balanced against outlet pressure varia-
tions, and a “standard” flow direction arrangement that is unbalanced. Refer to Technical Bulletin DA5-TB for design
conditions and selection recommendations. (NOTE: This product was formerly identified as a Model D5 or Type V;
a Model DA5, D5 and Type V are one and the same product.)
MODEL DA5
DA5 - DIRECT-ACTING, SPRING LOADED
BACK PRESSURE REGULATOR
SECTION I
II. REFERENCES
Refer to Technical Bulletin DA5-TB and DAG-TB for
technical specifications of a Model DA5 regulator.
ABBREVIATIONS
CCW – Counter Clockwise
CW – Clockwise
ITA – Inner Trim Assembly
III. INSTALLATION 4. Install block valves and pressure gauges to pro-
vide means for adjustment, operation, bypass, or
removal of the regulator. A pipeline strainer is
recommended upstream of inlet port to remove
typical pipeline debris from entering valve and
damaging internal “soft goods”, primarily the dy-
namic side seal and V-TFE seat when applied.
5. Upstream Sensing Installation Considerations –
Internal or External Sensing:
a. The regulator may be installed with internal
or external sensing. Unless otherwise speci-
fied, the regulator is supplied by the factory
with internal sensing. The regulator may be
converted in the field to external sensing. (See
Section VII maintenance, Part H – Converting
Internal/External Sensing.
b. Reference DAG-TB, Table DAG-12 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" (DN8) NPT on the side of the body
diaphragm flange (see following schematic)
to a pressure tap upstream of the regulator.
SECTION III
SECTION II
CAUTION
For welded installations, all internal trim parts, seals and
diaphragm(s) must be removed from regulator body prior
to welding into pipeline. The heat of fusion welding will
damagenon-metallicpartsifnotremoved. NOTE:Thisdoes
not apply to units equipped with extended pipe nipples.
1. Install per direction of flow arrow indicated on body,
or "IN" and "OUT" markings.
2. 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 be oriented downwards, and
that a customer supplied and installed vent valve
be provided at the external sensing connection
to bleed-off trapped gas/air under the diaphragm
during initial startup.
3. Provide space below, above, and around regulator
for removal of parts during maintenance.
ISO Registered Company

IOM-DA5
2
A tubing outside diameter of 0.25 inch is
adequate for short sensing lines (less than
4 feet). Use 3/8" tubing or 1/4" schedule 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 inlet piping to prevent water pockets, which
allows the diaphragm chamber to always be
self draining. The external sensing line may
be sloped upward for gas or liquid service;
i.e. non-condensibles.
IV. PRINCIPLE OF OPERATION
Recommended Piping Schematic
For Back Pressure/Relief Station
V. STARTUP
1 Start with the block valves closed.
2. Relax the range spring by turning the adjusting
screw CCW (viewed from above) a minimum of
three (3) full revolutions. This reduces the inlet
(upstream) pressure set point.
3. Crack open manual bypass valve. Initially pres-
surize system while simultaneously controlling
P1pressure through manual actuation of bypass
valve.
trap operation if installed. Closely monitor inlet
(upstream) 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).
5. Open the outlet (downstream) block valve.
6. Slowly open the inlet (upstream) block valve to
about 25% open, observing the inlet (upstream)
pressure gauge. Determine if the regulator is
flowing. If not, slowly rotate the regulator adjusting
screw CCW (viewed from above) until flow begins.
7. When flow is established steady enough that the
inlet (upstream) block valve can be fully opened,
begin to slowly close the bypass valve if installed.
8. Develop system flow to a level near its expected
normal rate, and reset the regulator set point by
turning the adjusting screw CW to increase inlet
pressure, or CCW to reduce inlet pressure.
9. Reduce system flow to a minimum level and ob-
serve pressure set point. Inlet pressure will de-
1. Movement occurs as pressure variations register
on the diaphragm. The registering pressure is the
inlet, P1, or upstream pressure. The range spring
opposes diaphragm movement. As inlet pressure
increases, the diaphragm pushes the range spring
SECTION IV
SECTION V
up,lifting the valve plug further off the seat; as inlet
pressure decreases, the range spring pushes the
diaphragm down closing the valve plug toward the
seat.
2. A complete diaphragm failure will cause the regu-
lator to fail closed and process fluid will discharge
from the spring chamber vent hole.
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.
CAUTION
DO NOT HYDROSTATIC TEST THROUGH AN INSTALLED
UNIT; ISOLATE REGULATOR FROM TEST. The upper range
spring pressure level on the nameplate is the recommended
“upper operating limit” for the sensing diaphragm. Higher
pressures could cause internal damage. See Table 2 in
DA5-TB for pressure limits of different diaphragm materials.
CAUTION
Do not walk away and leave a bypassed regulator
unattended!
4. If it is a “hot” piping system, and equipped with
a bypass valve, slowly open the bypass valve
to preheat the system piping and to allow slow
expansion of the piping. Ensure proper steam

IOM-DA5 3
crease from the set point of Step 8. The maximum
build in inlet pressure on increasing flow should not
exceed the stated upper limit of the range spring
by greater than 30%. If it does, consult factory.
VI. SHUTDOWN
1. Shutoff inlet block valve.
2. Remove range spring compression by turning the
adjusting screw CCW to reduce the inlet pressure.
3. Shutoff the outlet block valve.
4. Relieve the trapped upstream and downstream
pressure.
5. The regulator may now be removed from the
pipeline or disassembled for inspection and pre-
ventative maintenance while in-line.
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 requisi-
tion spare parts for the regulator. The informa-
tion should include: size, KM Product Code,
Serial Number.
3. Refer to Section IX for selection of recom-
mended spare parts. Only use original
equipment parts supplied by Cashco/KM 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 supplied as
“oxygen clean” – Opt-55, maintenance must
include a level of cleanliness equal to Cashco
cleaning standard #S-1134.
5. The Inner Trim Assembly (ITA) is removed and
replaced in the body (23) as an assemblage
of parts. The ITA consists of the following
parts:
Item Dynamic Side
No. Seal Type Part Description
7 ...................... All ........................... Diaphragm Fastener
(Cap Screw or Locknut)
8 ...................... All .......Upper Diaphragm Pressure Plate
9 ...................... All ...................................... Diaphragm(s)
10 ..................... All ..........Lower Diaphragm Pusher Plate
13 .................... All.........................Piston/Guide Bearing√
14 ..................... All ......................................... Stem Seals
14.1 ............... All ................................ Upper Stem Seal
14.2 ............... All ................................Middle Stem Seal
14.3 ............... All ..............................Lower Stem Seal√
14.4 ............... All ................ Lower Pusher Plate Gasket
20 ..................... All ...........................................Valve Plug
27 ..................... All ........................... Dynamic Side Seal *
27.1 ...............CP..................................... TFE Cap Seal
27.2 ...............CP......................... O-ring Energizer/Seal
27.3 .............. UC .......... U-Cup Seal w/Metal Energizer
27.5 ...............PR................................. Piston Ring Seal
27.6 ...............PR................. Piston Ring SST Energizer
28 ..................... All ............................................ Seat Disc
29 ..................... All ............................... Seat Disc Washer
30 ..................... All ......................................Seat Disc Nut
* The Dynamic Side Seal (27) and the Cage Seal (15) are
omitted for the FTC flow direction regulator. This is Type
NO. See Figure 1.
√2-1/2" thru 4" body sizes only.
SECTION VII
SECTION VI
A detailed view of the dynamic side seal parts is
shown in Figure 1 on the next page.

IOM-DA5
4
Figure 1: Dynamic Side Seals
(FTC Flow Direction Only)

IOM-DA5 5
B. Main Valve Disassembly:
1. Shut down the system in accordance with
Section VI.
2. Disconnect the external sensing line, if in-
stalled.
3. Though it is possible to disassemble the regu-
lator while installed in a pipeline, it is recom-
mended that maintenance be done in a shop
when possible. The descriptions hereafter will
assume shop disassembly. Remove regulator
from pipeline.
4. Place the body (23) in a vise with the spring
chamber (4) oriented upwards.
5. Loosen adjusting screw lock nut (2) and relax
range spring (6) forces by turning adjusting
screw (1) CCW (viewed from above) until
removed from spring chamber (4).
6. Loosen the diaphragm flange bolts (11) and
nuts (12) uniformly.
7. Place matchmarks on body (23) and spring
chamber (4) flanges. Completely remove bolt-
ing (11,12) Remove the spring chamber (4).
8. Remove spring follower (5) and range spring
(6).
9. Grasp opposite edges of diaphragm (9) and
withdraw the ITA from within the cage (19).
Set the ITA aside.
10. Evenly loosen the cage cap screws (18) in
single revolution increments until fully loos-
ened; remove cage cap screws (18).
11. Pull cage (19) up and out of body.
12. Remove o-ring cage seal (15).
13. Remove lower cage gasket (21).
14. Ifsupplied, remove internal sensing drilled plug
(32) using 5/32" (4 mm) Allen key wrench for
1/2" - 2" size regulators. Use 3/16" Allen key
wrench for 2 1/2" - 4" size regulators.
NOTE: Valves with “Large Internal Sensing” will not
be equipped with any plug (32,33).
15. For metal diaphragm constructions, remove
diaphragm gasket (37) from body (23) dia-
phragm flange.
16. Remove body (23) from vise. Solvent clean
all removed metal parts.
C. Disassembly of the ITA:
1. Body Sizes 1/2" – 2". (See Figures 3 and 4):
a. Obtain two pieces of square-section
barstock with a 3/8"-7/16" dimension,
approximately 2 inches long.
b. Place plug (20) into a vise using the bars
of a. above, use "flats" located on plug
(20) to prevent vise jaw marks from direct
surface contact with the plug (20). Orient
with diaphragms on topside.
c. Sizes 1/2"-1": Remove diaphragm locknut
(7) by rotating CCW.
Sizes 1-1/4"-2": Remove diaphragm cap-
screw (7) by rotating CCW.
d. Remove upper diaphragm pressure plate
(8).
e. Remove diaphragm(s) (9, 9.1, 9.2, 9.9).
Examine diaphragm(s) to determine
whether failed; determine if operating
conditions are exceeding pressure drop
or temperature limits.
f. For composition diaphragm construction,
remove upper stem seal (14.1).
g. For metal diaphragm construction, remove
lower pusher plate gasket (14.4).
h. Remove lower diaphragm pusher plate
(10).
i. Remove middle stem seal (14.2).
j. Remove plug (20) from vise, rotate end-
for-end, and re secure in vise using same
metal bars above.
k. Loosen seat disc nut (30) CCW (viewed
from above) approximately two (2) revolu-
tions.
l. Remove assembly (20, 27, 28, 29, 30)
from vise. Complete removal of seat disc
nut (30), seat disc washer (29), and seat
disc (28).
2. Body Sizes 2-1/2" – 4". (See Figure 2):
a. Place seat disc nut (30) into a vise with
the plug (20) oriented vertically. DO NOT
over-tighten nut (30) in vise.
b. Place closed-end hex wrench onto dia-
phragm locknut (7). Place socket wrench
on hex upper end of plug (20). Loosen
diaphragm locknut (7) while holding plug
(20) from rotating by socket wrench.
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-DA5
6
Remove diaphragm locknut (7) after fully
loosened and socket wrench is removed.
c. Remove upper diaphragm pressure plate
(8).
d. Remove diaphragm(s) (9, 9.1, 9.2, 9.9).
Examine diaphragm(s) to determine
whether failed; determine if operating
conditions are exceeding pressure drop
or temperature limits.
e. Remove upper stem seal (14.1).
f. Remove lower diaphragm pusher plate
(10).
g. Remove middle stem seal (14.2).
h. Remove piston/guide bearing (13) with
dynamic side seal (27) in place.
i. Remove lower stem seal (14.3).
j. Place socket wrench on upper end of plug
(20) as in Step b. above. Rotate plug (20)
CCW (viewed from above) to loosen seat
disc nut (30). Once nut (30) is loosened,
remove partial assembly (20, 27, 28, 29,
30) from vise. Complete removal of seat
disc nut (30), seat disc washer (29) and
seat disc (28).
3. Examine the components (27.1, 27.2, 27.3,
27.5, 27.6) of the dynamic side seal (27) 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
from plug (20) for sizes 1/2" – 2", or from
piston/guide bearing (13) for sizes 2-1/2" –
4". Special care should be taken when using
“tools” to remove the components to ensure
that no scratches are imparted to any portion
of the plug (20) or piston/guide bearing (13)
groove.
4. Solvent clean all metal parts to be reused.
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, etc.). Metal dia-
phragms should always be replaced. 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 Finish & Dimensional Requirements:
a. Valve plug (20);
1. No major defects on plug's (20) bottom
guide spindle, or at guide area near
dynamic seal groove.
b. Cage (19);
1. 16 rms finish on cylinder bore. No
“ledges” formed due to wear from
moving dynamic side seal (27).
2. 16 rms finish on its seating surface
for tight shutoff.
c. Lower guide bushing (24);
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). Drill out as required.
e. Piston/Guide Bearing (13)(2-1/2"-4" only);
1. No defects at guide area near dynamic
seal groove.
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.
E. Reassembly of the ITA:
1. Position valve plug (20) with seat disc-end
upwards. Place new seat disc (28) into re-
cess of lower end of valve plug (20) properly
oriented.
2. Position seat disc washer (29) next to seat
disc (28).
3. Engage seat disc nut (30) to secure washer
(29) and seat disc (28) to valve plug (20).
Firmly hand-tighten.
4. Body Sizes 1/2" thru 2":
a. Using the two square-section metal bar-
stock pieces of VII.C.1.a., clamp the plug
(20) into a vise with the plug's (20) spindle
pointed upwards.
b. Using a torque wrench, tighten the seat
disc nut (30) to 20-35 ft-lbs. by rotating
CW.
c. Remove assembly (20, 28, 29, 30) from
vise and rotate end-for-end and re secure

IOM-DA5 7
in vise using same metal bars.
5. Body Sizes 2-1/2" thru 4":
a. Orient plug (20) with threaded end up-
wards, place into a vise, grasping the seat
disc nut (30); tighten the vise lightly, only
enough to "hold" the plug (20) from rotating
out of the vise. Caution: Over-tightening
the vise can distort the seat disc nut (30)
and give bad final torque values.
b. Place a torque wrench on the 3/4" hex
upper end of the plug (20); tighten the
seat disc nut (30) to 40-60 ft-lbs by rotat-
ing CW.
6. Installation of dynamic side seal (27) (See
Figure 1): NOTE: Dynamic side seal (27) for
sizes 2-1/2"-4" is located on the piston/guide
bearing (13). The dynamic side seal can be
installed on a work bench without need of a
vise.
a. Type CP:
1. Stretch o-ring energizer/seal (27.2)
over lower circumference of valve
plug (20), 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 valve plug (20). NOTE: A very
slight amount of fluid and elastomer
compatible lubricant is recommended
as an installation aid. DO NOT “ROLL”
O-RING.
2. Position TFE cap seal (27.1) ring with
rectangular cross-section at lower end
of valve plug (20). Stretch cap seal
(27.1) over lower end of valve plug
(20) using thumbs to work the cap
seal (27.1) onto the valve plug (20).
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 valve plug (20).
b. Type PR:
1. Wrap corrugated metal piston ring
energizer (27.6) over lower circumfer-
ence groove of valve plug (20). Using
thumbs work the energizer (27.6) into
the valve plug (20) groove.
2. Spread a piston ring seal (27.5) and
slide over lower circumference groove
of valve plug (20), taking care not to
“cut” piston ring seal (27.5). Using
thumbs, work the piston ring seal
(27.5) into the groove of the valve plug
(20). Repeat this procedure with a
second piston ring seal (27.5). Orient/
rotate the "splits" in piston ring seals
(27.5) 180° across from each other.
c. Type UC:
1. Stretch u-cup seal (27.3) over upper
circumference of valve plug (20), tak-
ing care not to “cut” u-cup seal (27.3)
on the protruding shelf that is part of
the valve plug's (20) groove. Ensure
that the u-cup seal (27.3) is oriented
with the center-open-upwards as
shown in Figure 1, as the u-cup seal
(27.3) depends upon the P1-Inlet
Pressure to pressure activate the seal
for proper sealing action.
d. Type NO:
1. For “FTC” flow direction applications,
it is not required that a dynamic side
seal (27) be installed. (When included
with the dynamic seal (27), better
guiding of valve plug (20) results.)
Type “NO” dynamic seal (27) means
NO dynamic seal.
2. The more common “FTO Reverse”
flow direction always requires a dy-
namic side seal (27).
7. Place fluid compatible thread anti-seize,
Locktite Corp., "Nickel Anti-Seize", or equal
on threaded portion of diaphragm cap screw
(7), sizes 1-1/4" and 1-1/2"; or, threaded post
portion of valve plug (20), sizes 1/2" – 1" and
2-1/2" – 4". ( NOTE: Regulators cleaned for
oxygen service should use Fisher Scientific
Co., "Fluorolube GR-362", or equal.)
8. Body sizes 2-1/2" thru 4".
a. Place o-ring lower stem seal (14.3) over
upper-end of plug (20) and into groove
in plug (20).
b. Place properly oriented piston/guide bear-
ing (13) over upper-end of plug (20) and
into position on plug (20).
c. Place o-ring middle seal (14.2) over upper-
end of plug (20) and into groove of piston/
guide bearing (13).
9. Body sizes 1/2" thru 2".
Place new o-ring middle stem seal (14.2) into
groove of valve plug (20) upper surface.
10. Position lower diaphragm pusher plate (10) on/
over upper end of valve plug (20) properly ori-
ented. For composition diaphragm construc-
tion the “tongue and groove” “ridge” should
be on upper side, “flat” side downwards. For

IOM-DA5
8
metal diaphragm construction the “rounded”
surface of the lower diaphragm pusher plate
(10) should be on upper side, “flat” side down-
wards.
11. For composition diaphragm construction,
place new o-ring upper stem seal (14.1) on/
over upper end of valve plug (20) and into
groove of lower diaphragm pusher plate (10).
12. For metal diaphragm construction, place
compatible gasket sealant on both sides and
place new lower pusher plate gasket (14.4)
on/over upper end of valve plug (20) and onto
lower diaphragm pusher plate (10). (Gasket
sealant is Federal Process Corp. “Gasoila” , or
equal.) A Teflon gasket (37) may alternatively
be fitted between diaphragm and flange of
body.
13. Position new diaphragm(s) (9) on/over upper
end of valve plug (20). NOTE: For multiple
diaphragms (9) that include TFE material, the
TFE should be on the wetted side; for 3-ply
elastomeric TFE diaphragm (9), stackup is
TFE-HK-TFE, beginning with the lower wetted
diaphragm (9) first.
14. Position upper diaphragm pressure plate (8)
on/over upper end of valve plug (20) prop-
erly oriented. For composition diaphragm
construction the "tongue and groove" "ridge"
should be on lower side, "flat" side upwards.
For metal diaphragm construction the "round-
ed" surface of the upper diaphragm pressure
plate (8) should be on lower side, "flat" side
upwards.
15. a. Body sizes 1/2" thru 1": Engage dia-
phragm locknut (7) to threaded post
portion of valve plug (20) and torque
to 60-70 ft-lbs. by rotating CW.
b. Body Sizes 1-1/4" thru 2": Insert anti-
seize coated diaphragm cap screw
(7) through stacked parts (8, 9, 10,
14.1, 14.4) and into upper end of valve
plug (20). Torque-tighten diaphragm
cap screw (7) to 120-130 ft-lbs.
c. Body Sizes 2-1/2" thru 4": Engage dia-
phragm lock nut (7) to threaded post
of valve plug (20) and wrench-tighten
firmly. While restraining valve plug
(20) from rotating by torque wrench
on upper end 3/4" hex, use another
wrench to tighten diaphragm locknut
(7) to a torque of 180 - 200 ft-lbs.
16. This completes assembly of ITA; remove from
vise.
F. Main Reassembly:
1. Place body (23) in a vise.
2. Reinstall internal sensing drilled plug (32) with
compatible thread sealant.
3. Fit the o-ring cage seal (15) into its body (23)
groove for reverse flow regulators.
4. For metal diaphragm construction, place
sealant (“Gasoila” or equal) on both sides of
diaphragm gasket (37) and position on body
(23) diaphragm flange.
5. Position properly oriented lower cage gasket
(21) onto lower shoulder of cage (19).
6. Insert cage (19) into body (23) recess. Properly
align all three cage bolt (18) holes as there is
only one circumferential location possible for
this alignment. Engage all of the cage bolts
(18), then evenly screw in the cage bolts in
one-half revolution increments, taking care
NOT TO “COCK” THE CAGE (19) IN THE
BODY. Torque the cage bolts (18) to 13-15
ft-lbs.
7. Dynamic Side Seals:
a. Type CP: Position the ITA's valve plug
(20) lower end 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
valve plug (20) into the cage (19), simulta-
neously use hand thumbs to lightly press
the cap seal (27.1) inwards into the groove
of the valve plug (20) 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). Do not press
inwards on the cap seal (27.1) too much
or the cap seal (27.1) may slide out of its
groove.
b. Type PR: Position the ITA's valve plug
(20) lower end over and into upper end
of cage (19) until the lower piston ring
seal (27.5) touches the upper lip of the
cage (19). While gently applying force to
press the valve plug (20) into the cage
(19), simultaneously use fingers to lightly
circumferentially press the first (lower)
piston ring seal (27.5) inwards into the
valve plug (20) groove until the first piston

IOM-DA5 9
ring seal (27.5) “slips into” the cage (19).
Repeat for the second piston ring seal
(27.5)
c. Type UC: Position the ITA's valve plug (20)
lower end 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 valve plug
(20) into the cage (19), simultaneously
use hand thumbs to lightly press the u-
cup seal (27.3) inwards into the groove
of the valve plug (20) 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).
d. Type NO: Position the ITA's valve plug
(20) lower end over and into the cage
(19), allowing plug (20) to enter fully.
8. For composition diaphragm construction,
align diaphragm (9) bolt holes with body (23)
diaphragm bolt holes.
9. Place a small amount of heavy grease into
the adjusting screw (1) threaded opening of
spring chamber (4). Reengage both adjust-
ing screw (1) and its lock nut (2) with spring
chamber (4). Allow end of adjusting screw to
protrude into interior approximately 1/2 inch.
10. Place range spring (6) centered on upper
diaphragm pressure plate (8).
11. Place a dab of heavy grease in the recess of
the spring follower (5). Place spring follower
on upper end of range spring (6).
12. Aligning matchmarks and bolt holes, place
spring chamber (4) over range spring (6). If
spring chamber (4) flange reaches body (23)
flange without a gap, remove and lower ad-
justing screw (1) deeper into spring chamber
(4) cavity another 1/4 inch. Repeat this pro-
cedure until the adjusting screw (1) keeps the
two flanges from touching by approximately
1/8 inch.
13. 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” – pulled together to remove as much
entrapped air as possible and 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. Apply 30-50 psig pressure to the regula-
tor inlet and the regulator outlet.
OR
b. Block the valve inlet and outlet and apply
30-50 psig under the diaphragm through
the 1/4" NPT external pressure sens-
ing connection on the valve diaphragm
flange.
AND
c. Leave pressure on through tightening
of bolting (11,12).
14. 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
13.
G. 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 convert-
ing from external to internal sensing.
3. Reassemble the regulator according to Part
F – Main Regulator Reassembly.
H. Pressure Testing:
1. If a hydrostatic pressure test is performed,
pressure must be applied uniformly to the
spring chamber, inlet and outlet of body.
2. Inboard Leakage Test (Seat + Dynamic Seal
Leakage).
a. Determine test pressure. If upper value
of range spring is less than 55 psig, use
test pressure of 5 psig less than upper
value of range spring. If upper value of
range spring is greater than 55 psig, use
CAUTION
DO NOT HYDROSTATICALLY TEST WITHOUT SPRING
CHAMBER PRESSURIZED. NOT ADHERING WILL DO
PHYSICAL INTERNALS DAMAGE THAT COULD RENDER
THE UNIT INOPERABLE.
Body Size Torque
in. (DN) ft-lb (N-m)
1/2"-2" (15-50) 30-35 (41-47)
2 1/2"-4" (65-100) 45-50 (61-69)

IOM-DA5
10
test pressure of 50 psig.
b. While applying GN2or air pressurization
fluid, turn adjusting screw CCW until valve
appears to be closed. Add one additional
revolution CCW to adjusting screw.
c. Tube outlet to a beaker of water to observe
number of escaping gas bubbles.
3. Pressure Containment Test.
a. Pressurize inlet and outlet to 1.0 x Upper
Value of Range Spring or 30 psig with air
or GN2, whichever is higher.
b. Soap solution test all external leak points;
plugged connections, diaphragm flange,
diaphragm bolting and spring chamber
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.
Following are some of the more common complaints along with possible causes and remedies.
SECTION VIII
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
a 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.
1. Erratic regulation, instability or hunting.
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.)
vent opening.
4. Excessive leakage will require disassembly,
examination of sealing elements, correction
of problem, reassembly and retesting. NOTE:
This valve is NOT a bubble-tight shutoff de-
vice. See DAG-TB, Table DAG-10 for leakage
classes.

IOM-DA5 11
3. Upstream pressure too high.
Possible Causes Remedies
A. Debris in trim preventing movement. A. Clean unit of debris.
B. Undersized regulator. B. Check actual flow conditions; resize regulator for
minimum and maximum flow; if necessary, replace
with larger regulator.
4. Diaphragm continually breaks (steam service regulators).
Possible Causes Remedies
A. Stem seals, which protect fluorocarbon elastomer in
diaphragm assembly, may have deteriorated.
A. Replace with new seals.
B. Diaphragm nut may not be torqued to proper value. B. Confirm torque value in accordance with Section VII,
paragraph E-15.
C. Diaphragm too stiff causing it to crack in service. C. Follow proper preforming and air evacuation tech-
niques during diaphragm installation in accordance
with Section VII, paragraph F-13.
5. Diaphragm continually breaks (all regulators).
Possible Causes Remedies
A. Differential pressure across diaphragm may have
exceeded limits.
A. Reference limits as recorded in technical bulletin
DA5-TB, as well as where the various pressures
are acting.
6. Leakage at diaphragm flange.
Possible Causes Remedies
A. Body bolts not torqued high enough. A. Torque to proper value (see Section VII, paragraph
F-14).
7. Leakage across seat or dynamic side seal.
Possible Causes Remedies
A. Contamination (debris) in regulator. A. Remove internals, clean, and if necessary, replace
regulator.
B. Oversized regulator. B. Check actual flow conditions; resize regulator for
minimum and maximum flow; if necessary, replace
with smaller regulator.

IOM-DA5
12
SECTION IX
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.
Item No. Description
7 Diaphragm Cap Screw
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
19 Cage
20 Valve Plug
21 Lower Cage Gasket
24 Lower Guide Bushing
28 Seat Disk
29 Seat Disk Washer
30 Seat Disk Nut
Figure 2: Body Sizes
2-1/2" – 4", Composition Diaphragm
FTO – Reverse Flow Direction

IOM-DA5 13
Item No. Description
1 Adjusting Screw
2 Adjusting Screw Lock Nut
4 Spring Chamber
5 Spring Follower (Button)
6 Range Spring
7 Diaphragm Lock Nut
8 Upper Diaphragm Pressure Plate
9 ‡‡ Diaphragm
9.1 Diaphragm (Material #1)
9.2 Diaphragm (Material #2)
10 Lower Diaphragm Pusher Plate
11 Flange Bolts
12 * Flange Bolting Nuts
14 ‡‡ Stem Seal
14.2 Middle Stem Seal
14.4 Lower Pusher Plate Gasket
Item No. Description
18 Cage Cap Screws
19 Cage
20 Valve Plug
21 ‡‡ Seat Ring
23 Body
24 Lower Guide Bushing
26 Tap Plug (Not Shown)
28 ‡‡ Seat Disc
29 Seat Disc Washer
30 Seat Disc Nut
32 Internal Sensing Plug
(External Sensing Only)
33 Internal Sensing Drilled Plug
(Internal Sensing Only)
37 Diaphragm Gasket
99 Name Plate (Not Shown)
* Not required on 2" CS & SST Body Material.
‡‡ Recommended Repair Parts
Figure 3
Metal Diaphragm
FTO – Flow To Open

IOM-DA5
14
Item No. Description
1 Adjusting Screw
2 Adjusting Screw Lock Nut
4 Spring Chamber
5 Spring Follower (Button)
6 Range Spring
7 Diaphragm Cap Screw or 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 Bolting Nuts
14 ‡‡ Stem Seal
14.1 Upper Stem Seal
14.2 Middle Stem Seal
15 ‡‡ Cage Seal
18 Cage Cap Screws
Item No. Description
19 Cage
20 Valve Plug
21 ‡‡ Lower Cage Gasket
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
27.5 Piston Ring Seal
27.6 Piston Ring Energizer
28 ‡‡ Seat Disc
29 Seat Disc Washer
30 Seat Disc Nut
32 Internal Sensing Plug (External Sensing Only)
33 Internal Sensing Drilled Plug (Internal
Sensing Only)
99 Nameplate (Not Shown)
* Not required on 2" CS & SST Body Material.
‡‡ Recommeded Repair Parts
Figure 4
Composition Diaphragm
FTO – Flow to Open
Reverse Flow Direction

IOM-DA5 15
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.

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. DA5-IOM
Cashco do Brasil, Ltda.
Al.Venus, 340
Indaiatuba - Sao Paulo, Brazil
PH [phone]
Fax. No.
www.cashco.com
email: [email protected]
Cashco GmbH
Handwerkerstrasse 15
15366 Hoppegarten, Germany
PH [phone]
Fax. No. [phone]
www.cashco.com
email: [email protected]