cashco 123-1+6+S Instruction manual

IIl. PRINCIPLE OF OPERATION
1. Movement occurs as pressure variations register
on the diaphragm (3). The registering pressure is
the inlet (P1) or upstream pressure which registers
onthe"underneath"sideofthediaphragm(3). The
second pressure registered is the loading (PLOAD)
pressure in the spring chamber (2) "above" the
diaphragm (3). The range spring (18) determines
the differential pressure setpoint (PSET). As inlet
I. DESCRIPTION AND SCOPE
The Model 123-1+6+S Differential is designed for high pressure liquid or gas applications to Cashco drawing nos.
32934 (NACE construction) and 32935 (Non-NACE construction). It is used to control differential upstream (inlet or
P1) pressure and a loading (PLoad) pressure to a rotating shaft seal. Sizes are 1/2", 3/4", 1", and 1-1/2" (DN15, 20,
25, and 40).
SECTION III
IOM-123 1+6+S
DIFF
02-16
MODEL 123-1+6+S DIFFERENTIAL
BACK PRESSURE / RELIEF REGULATOR
INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)
SECTION I
SECTION II
II. INSTALLATION
This unit was designed and is used almost exclusively on compressor and turbo expander seal systems. REFER
TO COMPRESSOR/EXPANDER MANUFACTURER'S MANUAL FOR DETAILED INSTALLATION, START-UP
AND SHUTDOWN OF THIS UNIT. Install regulator with Inlet (P1) pressure coming in the side body (1) connection
in accordance with the directional flow arrow cast on body (1).
∆PSIZING = P1- P2
P1> PLOAD
P1= PLOAD + PSET
∆PDIFFERENTIAL = P1 - PLOAD
LOADING FLUID
@ PLOAD
DIAPHRAGM
RANGE SPRING:
SETTING @ PSET
(Optional)
INLET
@ P1
OUTLET @ P2
Model 123-1+6+S Differential Schematic
(P1) pressure drops, the range spring (18) pushes
the diaphragm (3) down, closing the port; as
inlet (P1) pressure increases, the diaphragm (3)
pushes up and the port opens. As the loading
(PLOAD) pressure varies, the inlet (P1) pressure
tends to follow. An increase in (PLOAD) will increase
inlet (P1)pressure by nearly an equal amount ;
a decrease in (PLOAD)will decrease the inlet (P1)
pressure.
2. A complete diaphragm (3) failure will cause the
fluids to mix in the spring chamber (2) or loading
pressure piping. Regulator action will "fail close"
under a diaphragm (3) failure.
3. Under normal operating conditions, the inlet (P1)
pressure should be greater than the loading
(PLOAD) pressure by the range spring (PSET)
setpoint.
INLET
@ P1
Limit any field hydrostatic test to 1-1/2 times the
Maximum Pressure Rating (See Table 1). Ensure
that the test pressure is applied uniformly to the
body inlet, body outlet, and spring chamber.
CAUTION
This is not a safety device and must not be substituted for a code approved pressure safety
relief valve or rupture disc. NOT FOR STEAM SERVICE. NOT FOR OXYGEN SERVICE.
CAUTION
ISO Registered Company

IOM-123-1+6 +S DIFF
2
VI. MAINTENANCE
A. General:
1. Maintenance procedures hereinafter are
based upon removal of the regulator unit from
the pipeline where installed.
V. SHUTDOWN
SECTION V
REFER TO THE COMPRESSOR/EXPANDER MANUFACTURER'S MANUAL FOR DETAILED SHUTDOWN OF
THIS UNIT.
1. On initial start-up with your system operating at
normal conditions, check the differential gauge to
ensure the desired differential pressure is being
maintained. If not, go to step 2 and make one final
adjustment. (This should only be necessary on
first start-up.) NOTE: It is crucial that the adjusting
screw (17) threads not be damaged. Do not use
pliers or locking pliers on the adjusting screw (17).
2. To adjust differential setting, use one of these two
methods:
a. Loosen the closing cap (22) by turning CCW
3-4 complete revolutions. Loosen lock nut (9)
by turning CCW until it is tight (double-nutted)
against closing cap (22). Now the differential
setting may be adjusted by turning the closing
cap (22) CW to increase differential or CCW
to decrease. After desired setting is reached,
loosen lock nut (9) from closing cap (22) and
tighten each securely to spring chamber (2).
b. Remove closing cap (22) from adjusting screw
(17) by turning CCW. Loosen lock nut (9) by
turning CCW. Turn the adjusting screw (17)
CW to increase differential pressure or CCW
to decrease. Tighten lock nut (9) and replace
closing cap (22).
REFER TO THE COMPRESSOR/EXPANDER MANUFACTURER'S MANUAL FOR DETAILED STARTUP OF
THIS UNIT.
IV. STARTUP
SECTION VI
WARNING
SPRING UNDER COMPRESSION. Prior to removing
spring chamber subassembly (2), relieve range spring
(18) compression by backing out the adjusting screw
(17). Failure to do so may result in flying parts that
could cause personal injury.
2. Owner should refer to owner's procedures for
removal, handling, cleaning and disposal of
nonreusable parts, i.e. gaskets, etc.
3. Refer to Figure 5 for differential regulator
cutaway drawing.
WARNING
SYSTEM UNDER PRESSURE. Prior to performing any
maintenance, isolate the regulator from the system and
relieve all pressure(s). Failure to do so could result in
personal injury.
TABLE 1
MAX OPERATING PRESSURES & TEMPERATURE RATING SPECIFICATIONS
DESCRIPTION
NPT and 1500# ANSI Flg. 600# ANSI Flg. 900# ANSI Flg.
100°F
(38°C)
400°F
(205°C)
100°F
(38°C)
400°F
(205°C)
100°F
(38°C)
400°F
(205°C)
psig (Barg) psig (Barg) psig (Barg) psig (Barg) psig (Barg) psig (Barg)
Max. Pressure for CS Body/Spg. Ch, 1500 (103) 1500 (103) 1480 (102) 1270 (88) 1500 (103) 1500 (103)
Max. Pressure for SST Body/Spg. Ch. 1500 (103) 1500 (103) 1440 (99) 995 (69) 1500 (103) 1500 (103)
Operating Temperature Range -20°F (-28°C) to +400F (+204C)
SECTION IV

IOM-123-1+6 +S DIFF 3
B. Disassembly:
1. Securely install the body (1) in a vise with the
spring chamber (2) directed upwards.
2. Remove closing cap (22).
3. Loosen sealing locknut (9) by rotating CCW.
Relax range spring (18) by turning adjusting
screw (17) CCW.
4. Draw or embed a match mark between
body (1) casting and spring chamber (2)
subassembly along flanged area.
5. Remove all body flange hardware
(7,8,30,41,42).
6. Remove spring chamber (2) and connected
parts, range spring (18) and spring button
(19).
DO NOT ATTEMPT TO REMOVE ADJUSTING SCREW
(6) FROM TOP OF SPRING CHAMBER (2). The
adjusting screw (6) is threaded up from inside the
spring chamber (2) and the CCW rotation used to
relieve range spring (14) tension will come to a stop.
At the stopping point, do not apply any torque to
adjusting screw (6) or damage may occur and render
the unit inoperable. See Figure 1.
CAUTION
7. Adjusting screw (17) o-ring inspection:
a. With locknut (9) and closing cap (22)
removed, turn adjusting screw (17) CW
as far as possible by grasping the flats
on top end. Carefully reach inside spring
chamber (2) and grasp adjusting screw
(17) by hand. Remove adjusting screw
(17) by rotating CCW. See Figure 1A.
b. Inspect the backup ring (28) and quad ring
(29) for wear. If nicked or torn - replace.
NOTE: Make certain the teflon backup
ring (28) will insert into spring chamber
(2) first, before the quad ring (29). (See
Figure 7 blow-up illustration). Make sure
the quad ring (29) is on straight with
no twist. Use a good grade lightweight
grease on the ring seals (28,29).
c. Lubricate adjusting screw (17) threads.
Carefully reinstall adjusting screw (17)
up into the spring chamber (2) by rotating
adjusting screw (17) CW until top of
adjusting screw (17) protrudes from top
of spring chamber (2) (See Figure 1B.).
NOTE: Care should be taken when
holding and rotating adjusting screw (6)
so the quad ring (29) and backup ring
(28) are not inadvertently nicked or torn.
Grasp top of adjusting screw (17) and turn
CCW until rotation stops (see CAUTION
C).
d. Loosely install the lock nut (9) and closing
cap (22).
8. Liftupandremovethediaphragmsubassembly
consisting of the piston (14), piston nut (6),
diaphragm (3), diaphragm covers (24) (NACE
unit only, Cashco Dwg. 32934), pressure
plate (20), pusher plate (21), sealing washer
(27), pressure plate o-ring (31) and pusher
plate o-ring (34). Remove the flange o-ring
(32).
9. Loosen piston nut (6) and separate all parts
(3,24 (NACE units only),14,20,21,27,31,34)
of the diaphragm (3) subassembly.
Figure 1: Adjusting screw (17) o-ring inspection.
9
28
29
28
29
9
17
17
2
B. Reassembly
A. Removal
2
When body flange hardware (7,8,30,41,42) is removed
from this unit it should always be replaced with new.
The new hardware (7,8,30,41,42) must have the proper
grade specification identification markings and meet
the following standards:
1. All cap screws (7,30) and flange stud nuts (8)
must have "heavy hex heads".
2. All studs (41,42) and cap screws (7,30) must
comply with or exceed the requirements of
ASTM-A-193, Grade B7.
3. All flange stud nuts (8) must comply with
or exceed the requirements of ASTM A-194,
Grade 2H.
New body flange hardware (7,8,30,41,42) may be
purchased from Cashco, Inc. or through the OEM.
CAUTION

IOM-123-1+6 +S DIFF
4
6. Place pusher plate o-ring (34) into recess of
pusher plate (21). Lubricate with good grade
lightweight grease.
7. Place diaphragm (3) and diaphragm covers
(24) (NACE construction only) according to
following instructions:
a. NACE variation only (Cashco Dwg.
#32934): Place one of the two diaphragm
cover(s) (24) over piston (14) post. Place
diaphragm (3) and second diaphragm
cover (24) over piston (14) post.
b. NON-NACE variation only (Cashco
Dwg. #32935): Place diaphragm (3)
over piston (14) post.
8. Place pressure plate o-ring (31) into recess
of pressure plate (20). Lubricate with a good
grade lightweight grease. Position pressure
plate (20) over the piston (14) post.
9. Place the sealing washer (27) (metal side up)
over the piston (14) post.
10. Thread piston nut (6) onto piston (14) post.
Torque to the following value:
All sizes: 45-50 Ft-lbs (61-68 N-m).
11. Release the piston (14) from vise. Insert the
piston/diaphragm subassembly into the body
(1) with piston (14) engaging the cylinder (12).
Align diaphragm (3) and body (1) bolt holes.
12. Place the range spring (18) onto the retainer
hub of the pressure plate (20).
13. Place multipurpose, high temperature grease
into depression of spring button (19) where
adjusting screw (17) bears. Set spring button
(19) onto range spring (18); ensure spring
button (19) is laying flat.
14. Aligning matchmarks, place spring chamber
(2) over the stacked parts. Rotate adjusting
screw (17) CW into spring chamber (2)
until contact is made with the spring button
(19). NOTE: Contact will begin to lift the
spring chamber (2) up from body (1). Relax
adjustment screw (17) so that spring chamber
(2) and body (1) just make contact. (This will
keep the range spring (18) from falling over
while the body (1) and spring chamber (2) are
bolted back together).
10. Inspect pressure plate (20) and pusher plate
(21) to assure no deformation due to over-
pressurization. Inspect diaphragm (3). If
deformed, replace.
11. Remove cylinder subassembly (12) by
rotating CCW. NOTE: For 1-1/2" (DN40)
body reduced orifice only, also remove the
cylinder bushing (33) at this time. See Figure
6.
12. Inspect cylinder seat (12.2). If seat shows
erosion or wear, the entire cylinder/seat
assembly (12) must be replaced.
13. Remove body (1) from vise.
14. Clean all parts to be reused according
to owner's procedures. Use special care
cleaning the flat mating surfaces of the body
(1), cylinder (12) and cylinder bushing (33)
shoulders (1-1/2" (DN40) size only) as these
pressurized joints are metal-to-metal.
C. Reassembly:
1. Place body (1) back into vise.
2. a. For standard orifice: Lubricate the
cylinder (12) threads lightly with thread
sealant, insert the cylinder (12) into the
body (1) and screw CW until finger tight.
Impact the cylinder (12) into the body (1).
b. For 1-1/2" (DN40) body reduced orifice
ONLY: Lubricate cylinder (12) and
cylinder bushing (33) threads lightly with
thread sealant. Screw the cylinder (12)
into the cylinder bushing (33) until finger
tight. Then screw the cylinder (12) and
cylinder bushing (33) "subassembly"
into the body (1) until finger tight. Impact
this cylinder (12)/cylinder bushing (33)
"assembly" into the body (1). See Figure
6.
3. Place diaphragm flange o-ring (32) on body
(1) flange.
4. Place piston (14) in a vise with threaded post
portion directed upwards, grasping on the
hexagonal surface.
5. Position properly oriented pusher plate (21)
over piston (14) post.

IOM-123-1+6 +S DIFF 5
15. Using "NEW" studs (41,42) and nuts (8) (see
CAUTION D), thread one nut (8) onto each
stud (41,42) approximately 1.25" (32 mm).
Drop the studs (41,42) with nuts (8) through
holes in spring chamber (2). (This will assist
in keeping the spring chamber (2) centered on
valve body (1) and prevent parts from moving
during reassembly).
Using "match marks" made in Step B.4 as a
guide, replace spring chamber (2) onto body
(1). Thread lower nuts (8) onto studs (41,42)
and tighten by hand. Adjust length of studs
(41,42) by using the top nut (8) to allow at
least 3-4 threads protruding from the lower
nut (8).
Torque body flange hardware (7,8,30,41,42)
using small increments in a 180° alternating
pattern until flange mating surfaces of body
(1) and spring chamber (2) are metal to
metal. This creates a "fixed compression"
on the diaphragm (12) and o-ring seal (32).
Recommended torque values are listed in
Table 2.
differential setting, check seat leakage
at 40% below 15 psig (1.0 Barg); or 9
psig (.62 Barg). Seat leakage should
be minimal (less than 20 SCFH). See
SECTION VII-5. TROUBLE SHOOTING
GUIDE if seat leakage is excessive.
2. Proof test to check for external leakage.
a. Close No. 1, No. 3, and No. 5 shut-off
valves. Open No. 2 and No. 4 shut-off
valves. Build inlet pressure to No. 1 shut-
off valve to 1-1/2 times maximum inlet
pressure, but not to exceed 1-1/2 times
Maximum Pressure Rating (See Table 1).
b. Crack open No.1 shut-off valve and allow
a pressure buildup simultaneously in the
body (1) and spring chamber (2). Spray
the entire regulator with a liquid leak
detector and visually inspect for external
leakage. Repair unit if leak is detected.
See SECTION VI MAINTENANCE.
c. Shut off line pressure to No. 1 shut-off
valve. Open No. 3 shut-off valve to
relieve all pressure from the test valve
and all shut-off valves.
3. Return to Section II for Installation and
Section IV for Startup.
TABLE 2
D. Bench test for suitable operation (Test Fluid:
Air or compressed gas).
1. Check for desired differential spring setting
and regulator performance (with no loading
pressure):
a. Close No. 1, No. 2, and No. 4 shut-off
valves. Open No. 3 and No. 5 shut-off
valves.
b. Apply inlet (P1) pressure to No. 1 shut-off
valve (10-15 psig (.69-1.0 Barg) above
desired differential spring setting). Crack
open No. 1 shut-off valve and check
for valve opening at desired differential
setting. Refer to SECTION IV-2. if range
spring (18) adjustment is required.
c. Check for performance. NOTE: A
metal seat will experience a slight
seat leakage). Seat leakage should be
quantified at 40% deviation from setpoint.
For example: For a 15 psid (1.0 Bard)
No. 1
Shut-off
Valve
No. 2
Shut-off
Valve
Pressure
Gauge
No. 3
Shut-off
Valve
Inlet P1
Pressure
Outlet P2
Pressure
No. 5 Isolation Valve
No. 4
Shut-off
Valve
Figure 2: Recommended Bench Test
Piping Schematic for 123-1+6+S
BODY SIZE ITEM
NO.
THREAD
SIZE
TORQUE VALUE
in (DN) Ft-lbs (N-m)
1/2" - 1-1/2" (15-40) 7, 8, 30,
41, 42 7/16-20 32-36 (43-49)

IOM-123-1+6 +S DIFF
6
SECTION VII
VII. TROUBLE SHOOTING GUIDE
1. Erratic Operation; chattering
Possible Causes Remedies
A. Oversized regulator. A1. Check actual flow conditions, resize regulator for minimum and
maximum flow.
A2. Increase flow rate.
A3. Install next step higher range spring. Contact factory.
A4. Before replacing regulator, contact factory.
B. Inadequate rangeability. B1. Increase flow rate.
B2. Decrease regulator pressure drop.
B3. Install next step higher range spring. Contact factory.
C. Worn piston/cylinder; inadequate guiding. C. Replace trim.
D. Unstable loading pressure. D1. Stabilize loading pressure; i.e. pump, control, valve, etc.
D2. Air in loading piping in liquid service. Vent as fully as possible.
2. Regulator inlet (upstream) pressure too high.
Possible Causes Remedies
A. Regulator undersized. A1. Confirm by opening bypass valve together with regulator.
A2. Check actual flow conditions, resize regulator; if regulator has
inadequate capacity, replace with larger unit.
B. Plugged inlet strainer. B. Remove strainer screen and clean; consider leaving screen out.
C. Plugged trim. C. Remove trim and check for plugged holes in cylinder.
D. Incorrect range spring (screwing out CCW of
adjusting screw does not allow bringing
pressure level to a stable and proper level).
D. Replace range spring with proper lower range. Contact factory.
E. Too much proportional band (rise). E1. Review Proportional Band (rise) expected.
E2. Contact factory.
F. Restricted diaphragm movement. F1. Ensure no moisture in spring chamber at temperatures below
freezing.
F2. Ensure no dust or debris entering vent opening. If rainwater or
debris can enter, re-orient spring chamber.
G. Diaphragm failure. G. Replace diaphragm.
3. Main valve fluid in loading fluid piping.
Possible Causes Remedies
A. Normal-life diaphragm failure. A. Replace diaphragm.
B. Abnormal short-life diaphragm failure. B1. Can be caused by excessive chattering. See No. 1 to remedy
chatter.
B2. Ensure not subjecting diaphragm to over-temperature conditions.
B3. Upstream (inlet) pressure buildup occurring that overstresses
diaphragms.
4. Sluggish operation.
Possible Causes Remedies
A. Plugged piston guides. A. Remove trim and clean.
B. Fluid too viscous. B. Heat fluid. Contact factory.
C. Diaphragm failure. C. Replace diaphragm.
5. Excessive seat leakage.
Possible Causes Remedies
A. Foreign matter on seating surface. A. Remove trim and clean.
B. Erosion/damage to seating surface. B1. Relap seating surface.
B2. Replace cylinder sub-assembly and piston.

IOM-123-1+6 +S DIFF 7
POSITION OF MOUNTING BRACKET STUDS
SECTION VIII
Figure 4: 1-1/2" (DN40) Body Size
Figure 3: 1/2" & 3/4" (DN15 & DN20) Body Sizes
Bolt Circle
1/2" (DN15) NPT
Loading
Pressure
Connection
Bolt Circle
Position of Longer Studs
(41,42) used for mounting
customer supplied bracket.
Position of two "Short" Cap
Screws (7,30) must straddle
1/2" (DN15) NPT Loading
Pressure Connection.
1/2" (DN15) NPT
Loading
Pressure
Connection
Position of Longer Studs
(41,42) used for mount-
ing customer supplied
bracket.
Position of two "Short" Cap
Screws (7,30) must straddle
1/2" (DN15) NPT Loading Pres-
sure Connection
Body SIze No. of 1/2" (12.7 mm)
Dia. Bolt Holes
Bolt Circle Position
in (DN) in (mm) A B
1/2", 3/4",
1"
(15, 20,
25) 12 6-1/4" (159 mm) 15° 30°
1-1/2" (40) 16 7-1/2" (191 mm) 11.25° 22.5°
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–
VIII. 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
(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).
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.
PARTS "KIT" for FIELD REPAIR:
Contact your local Cashco, Inc., Sales Representa-
tive with the Serial Number and Product code. Identify
the parts and the quantity required to repair the unit
from the Bill of Materials 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.
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 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.

....... Repair
Item No. Description Parts
1 ..................................................Body
2 ................................Spring Chamber
3 .........................................Diaphragm
6 ..........................................Piston Nut
7 ..................... Cap Screw (Hex Head)
8 ...........................................Nut (Hex)
9 ............................................Lock Nut
10 .................. Name Plate (not shown)
12 ....................Cylinder Sub-Assembly
12.1...................................... Cylinder
12.2............................................Seat
14 ............................................... Piston
17 ............................... Adjusting Screw
18 ................................... Range Spring
19 ................................... Spring Button
9
2
19
18
6
27
42 41
8
3
1
21
34
12.2
12.1
12
22
17
28
29
Seal Welded per ASME
BPVC Code Section IX
1/2" (DN15) NPT
Loading Connection.
20
730
32
31
35
14
Seal welded per ASME BPVC
Code Section IX & API 614
(Both Nipples)
Figure 6: Cylinder Bushing (33)
(Used on 1-1/2" (DN40)
reduced orifice ONLY)
33
Figure 5: Model 123-1+6+S
(Non-NACE Construction)
Opt-33 Third Body
Connection
....... Repair
Item No. Description Parts
20 ................................. Pressure Plate
21 .................................... Pusher Plate
22 ..................................... Closing Cap
24 ..........................Diaphragm Covers1
27 ................................Sealing Washer
28 .....................................Backup Ring
29 ........................................Quad Ring
30 .....................Cap Screw (Hex head)
31 ...................... Pressure Plate O-ring
32 ................ Diaphragm Flange O-ring
33 ..............................Cylinder Bushing
(Used on 1-1/2" Reduced Orifice only)
34 ......................... Pusher Plate O-ring
35 ..........................................Pipe Plug
41 ..................................................Stud
42 ..................................................Stud
17
29
28
Figure 7: Orientation of
Ring Seals (28,29)
*
*
*
*
*
*
*
**
*
*
*
*
**
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
1NACE Construction only (not shown).
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. IOM-123-1+6+S
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]

ATEX 94/9/EC: Explosive Atmospheres and Cashco Inc. Regulators
These valves satisfy the safety conditions according to EN 13463-1 and EN 13463-5 for equipment group IIG 2 c.
Caution: Because the actual maximum temperature depends not on the equipment itself, but upon the fluid temperature, a
single temperature class or temperature cannot be marked by the manufacturer.
Specific Precaution to Installer: Electrical grounding of valve must occur to minimize risk of effective electrical discharges.
Specific Precaution to Installer: Atmosphere vent holes should be plugged to further minimize the risk of explosion.
Specific Precaution to Maintenance: The Valve Body/ Housing must be regularly cleaned to prevent buildup of dust deposits.
Specific Precaution to Maintenance: Conduct periodic Continuity Check between Valve Body/ Housing and Tank to minimize
risk of electrical discharges.
Attention: When repairing or altering explosion-protected equipment, national regulations must be adhered to. For maintenance
and repairs involving parts, use only manufacturer's original parts.
ATEX requires that all components and equipment be evaluated. Cashco pressure regulators are considered components.
Based on the ATEX Directive, Cashco considers the location where the pressure regulators are installed to be classified
Equipment-group II, Category 3 because flammable gases would only be present for a short period of time in the event of a leak.
It is possible that the location could be classified Equipment-group II, Category 2 if a leak is likely to occur. Please note that the
system owner, not Cashco, is responsible for determining the classification of a particular installation.
Product Assessment
Cashco performed a conformity assessment and risk analysis of its pressure regulator and control valve models and their
common options, with respect to the Essential Health and Safety Requirements in Annex II of the ATEX directive. The details
of the assessment in terms of the individual Essential Health and Safety Requirements, are listed in Table 1. Table 2 lists all of
the models and options that were evaluated and along with their evaluation.
Models and options not listed in Table 2 should be assumed to not have been evaluated and therefore should not be selected
for use in a potentially explosive environment until they have been evaluated.
Standard default options for each listed model were evaluated even if they were not explicitly listed as a separate option in the
table. Not all options listed in the tables are available to all models listed in the tables. Individual TB’s must be referenced for
actual options.
When specifying a regulator that is to be used in a potentially explosive environment one must review the evaluations in Table 1
and 2 for the specific model and each and every option that is being specified, in order to determine the complete assessment
for the unit.
A summary of the models and options found to have an impact on ATEX assessment due to potential ignition sources or other
concerns from the ATEX Essential Health and Safety Requirements, are listed below.
1. The plastic knob used as standard on some models, (P1, P2, P3, P4, P5, P7, 3381, 4381, 1171, and 2171) is a
potential ignition source due to static electricity. To demonstrate otherwise, the knob must be tested to determine
if a transferred charge is below the acceptable values in IEC 60079-0 Section 26.14 (See items 25, 27, and 28 in
Appendix A). Until the plastic knob has been shown to be acceptable, then either the metal knob option, or a preset
outlet pressure option is required to eliminate this ignition source (See items 45 and 64 in Tables).
2. The pressure gauges offered as options on a few of the regulator models (DA’s, P1-7, D, 764, 521), use a plastic
polycarbonate window that is a potential ignition source due to static electricity. To demonstrate that the gauges are
not a potential source of ignition, the gauges would need to be tested to determine if a transferred charge is below
the acceptable values in IEC 60079-0 Section 26.14 or the pressure gauge supplier must provide documentation
indicating the gauge is compliant with the ATEX Directive (See items 26, 27, and 28 in Appendix A). Until compliance
is determined, regulators should not be ordered with pressure gauges for use in potentially explosive environments.
NOTICE
Only for Product Codes wherein hazard
category ATEX has been selected.

IOM-123-1+6 +S DIFF
10
3. Tied diaphragm regulators with outlet ranges greater than 100 psig should be preset to minimize the risk that improper
operation might lead to an outboard leak and a potentially explosive atmosphere (See item 6 in Table 1).
4. Regulators must be ordered with the non-relieving option (instead of the self-relieving option) if the process gas they are
to be used with is hazardous (flammable, toxic, etc.). The self-relieving option vents process gas through the regulator
cap directly into the atmosphere while the non-relieving option does not. Using regulator with the self- relieving option
in a flammable gas system could create an explosive atmosphere in the vicinity of the regulator.
5. Regulators with customer supplied parts are to be assumed to not have been evaluated with regard to ATEX and thus
are not to be used in a potentially explosive environment unless a documented evaluation for the specific customer
supplied parts in question has been made. Refer to Table 1 for all models and options that have been evaluated.
Product Usage
A summary of ATEX related usage issues that were found in the assessment are listed below.
1. Pressure regulators and control valves must be grounded (earthed) to prevent static charge build-up due to the flowing
media. The regulator can be grounded through any mounting holes on the body with metal to metal contact or the
system piping can be grounded and electrical continuity verified through the body metal seal connections. Grounding
of the regulator should follow the same requirements for the piping system. Also see item 30 in Table 1.
2. The system designer and users must take precautions to prevent rapid system pressurization which may raise surface
temperatures of system components and tubing due to adiabatic compression of the system gas.
3. Heating systems installed by the user could possibly increase the surface temperature and must be evaluated by the
user for compliance with the ATEX Directive. User installation of heating systems applied to the regulator body or
system piping that affects the surface temperature of the pressure regulator is outside the scope of this declaration and
is the responsibility of the user.
4. The Joule-Thomson effect may cause process gases to rise in temperature as they expand going through a regulator.
This could raise the external surface temperature of the regulator body and downstream piping creating a potential
source of ignition. Whether the Joule-Thomson effect leads to heating or cooling of the process gas depends on
the process gas and the inlet and outlet pressures. The system designer is responsible for determining whether the
process gas temperature may rise under any operating conditions. If a process gas temperature rise is possible under
operating conditions, then the system designer must investigate whether the regulator body and downstream piping
may increase in temperature enough to create a potential source of ignition.
The process gas expansion is typically modeled as a constant enthalpy throttling process for determining the temperature change.
A Mollier diagram (Pressure – Enthalpy diagram with constant temperature, density, & entropy contours) or a Temperature –
Entropy diagram with constant enthalpy lines, for the process gas, can be used to determine the temperature change. Helium
and hydrogen are two gases that typically increase in temperature when expanding across a regulator. Other gases may
increase in temperature at sufficiently high pressures.
Product Declaration
If the above issues are addressed by selecting options that do not have potential sources of ignition, avoiding options that
have not been assessed, and by taking the proper usage issue precautions, then Cashco regulators can be considered to be a
mechanical device that does not have its own source of ignition and thus falls outside the scope of the ATEX directive.