cashco HP-1+6+S Instruction manual

INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM) IOM-HP-S-
DIFF
12-16
MODEL HP-1+6+S
HIGH PRESSURE DIFFERENTIAL
REDUCING REGULATOR
I. DESCRIPTION AND SCOPE
The Model HP-1+6+S is a heavy duty, high pressure
differential reducing regulator used to control
differential pressure between downstream outlet (P2)
pressure and a loading (PLOAD) pressure to the spring
chamber. This unit applies to Cashco drawing nos.
32911 (Non-NACE construction), 32909 (CS NACE
construction), or 32907 (SST NACE construction).
Sizes are 1/2", 3/4", and 1-1/2" (DN15, 20, and
II. INSTALLATION
This unit was designed and is used almost exclusively on compressor and turbo expander seal gas systems. REFER
TO COMPRESSOR / EXPANDER MANUFACTURER'S MANUAL FOR DETAILED INSTALLATION, START-UP
AND SHUTDOWN OF THIS UNIT. Install regulator in accordance with direction of flow arrow cast on body (1).
SECTION III
III. PRINCIPLE OF OPERATION
1. The HP-1+6+S is used to maintain a constant
differential pressure across the seals of a
compressor/expander. A differential pressure
reducing regulator senses the downstream or
outlet (P2) pressure on the lower side of the
diaphragm and is opposed by the force of the
range spring plus an additional loading (PLOAD)
pressure connected to the spring chamber. The
loading (PLOAD) pressure plus the range spring
(14) setting (PSET) equals the outlet (P2) pressure
of the regulator. The range spring setting (PSET) is
the differential setting.
SECTION II
HP-1+6+S
DIFFERENTIAL SCHEMATIC
SECTION I
CAUTION
NOT FOR STEAM SERVICE. NOT FOR OXYGEN SERVICE.
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.
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
Option-1+6 contains single diaphragm construction. In
the event of diaphragm failure, the process fluid will mix
with the loading fluid. Please alert your representative so
an alternative product can be selected.
40). This unit is most commonly applied to develop
a constant differential pressure across a rotating
shaft seal to provide proper sealing and lubricating
conditions over varying pressure ranges. Refer
to Technical Bulletin HP-S-DIFF-TB for design
conditions and selection recommendations.
ISO Registered Company

IOM-HP-S-DIFF
2
V. SHUTDOWN
SECTION V
SECTION IV
* NOTE: Systems sequencing operations at startup,
normal operation, failure mode(s), and shutdown must
assure that the pressure (PLoad) on the spring chamber does
not exceed the pressure registering on the wetted side of
the diaphragm. Should this "pressure reversal" occur,
particularly to metal diaphragms, the diaphragm may be
permanently damaged and cause improper operation.
P1> P2> PLoad
Pressure reversal is normally caused by the inlet pressure
toaregulatorbeinginterrupted(automaticallyormanually).
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 (6) threads not be damaged. Do not use
any type of pliers on the adjusting screw (6).
REFER TO THE COMPRESSOR / EXPANDER MANUFACTURER'S MANUAL FOR DETAILED SHUTDOWN
OF THIS UNIT.
2. To adjust differential setting, use one of the two
following methods: (NOTE: Both methods require
a flowing condition.)
a. Loosen the closing cap (28) by turning CCW
(as viewed from above) 3 to 4 complete
revolutions. Loosen lock nut (7) by turning CCW
until it is tight (double-nutted) against closing
cap (28). Now the differential setting may be
adjusted by turning the closing cap (28) CW
to increase differential or CCW to decrease.
After desired setting is reached, loosen lock
nut (7) from closing cap (28) and tighten each
securely to spring chamber (2).
b. Remove closing cap (28) from adjusting screw
(6) by turning CCW. Loosen lock nut (7) by
turning CCW. Adjust the differential setting by
turning the adjusting screw (6) CW to increase
differential pressure or CCW to decrease.
Tighten lock nut (7) securely to spring chamber
(2). Replace closing cap (28) and tighten.
REFER TO THE COMPRESSOR / EXPANDER MANUFACTURER'S MANUAL FOR DETAILED START-UP OF
THIS UNIT.
IV. STARTUP
CAUTION
Limit any field hydrostatic test to 1-1/2 times the Maximum
Outlet and Spring Chamber Pressure Rating (See Table
2 in HP-S-DIFF TB). Ensure that the test pressure is
applied uniformly to the body inlet, body outlet, and spring
chamber.
2. A complete diaphragm failure will cause the
regulator to fail open.

IOM-HP-S-DIFF 3
6. Adjusting screw (6) o-ring inspection:
a. With locknut (7) and closing cap (28)
removed, turn adjusting screw (6) CW
as far as possible by turning flats on
top end. Carefully reach inside spring
chamber (2) and grasp adjusting screw
(6) by hand. NOTE: For 1/2" (DN15)
and 3/4" (DN20) size regulators a small
piece of plastic tubing with a 3/4" (19 mm)
inside diameter may be used to grasp the
adjusting screw (6). Complete adjusting
screw (6) removal by rotating CCW. See
Figure 1.
b. Inspect the backup ring (32) and quad ring
(31) for wear. If nicked or torn - replace.
NOTE: Make certain the Teflon backup
ring (32) will insert into spring chamber (2)
before the quad ring (31). (See Figure 3
blow-up illustration). Make sure the quad
ring (31) is on straight with no twist. Use
a good grade lightweight grease on both
ring seals (31,32).
A. General:
1. Maintenance procedures hereinafter are
based upon removal of the regulator unit from
the pipeline where installed.
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 3 for view of regulator.
WARNING
SPRING UNDER COMPRESSION. Relieve spring
compression prior to removing diaphragm flange bolts.
Failure to do so may result in flying parts that could cause
personal injury.
CAUTION
DO NOT ATTEMPT TO REMOVE ADJUSTING SCREW (6)
FROM TOP OF SPRING CHAMBER (2). The adjusting
screw (6) is threaded upward from inside the spring
chamber (2). 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
When body flange hardware (9,23,34,35) is removed
from this unit it should always be replaced with new.
The new hardware (9,23,34,35) must have the proper
grade specification identification markings and meet the
following standards:
1. All cap screws (23) and flange stud nuts (9) must have
"heavy hex heads".
2. All studs (34,35) and cap screws (23) must comply with
or exceed the requirements of ASTM A-193, Grade B7.
3. All flange stud nuts (9) must comply with or exceed
the requirements of ASTM A-194, Grade 2H.
New body flange hardware (9,23,34,35) may be purchased
from Cashco, Inc. or through the OEM.
Figure 1: Adjusting screw (6) o-ring inspection.
B. Diaphragm Replacement:
1. Securely install the body (1) in a vise with the
spring chamber (2) directed upwards.
2. To relieve range spring (14) compression,
remove closing cap (28) by turning CCW.
Remove lock nut (7) by turning CCW. Turn
adjusting screw (6) CCW until range spring
(14) compression is relieved. NOTE: See
CAUTION C).
3. Draw or embed a match mark between body
(1) casting, body spacer (24), and spring
chamber (2) casting along flanged area.
4. Removeallbodyflangehardware(9,23,34,35).
5. Remove spring chamber (2), range spring
(14),spring button (4),pressure plate (3),body
spacer (24), diaphragm (12), and o-rings (30).
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.
SECTION VI
VI. MAINTENANCE

IOM-HP-S-DIFF
4
c. Lubricate adjusting screw (6) threads.
Carefully reinstall the adjusting screw (6)
up into the spring chamber (2) by rotating
the adjusting screw (6) CW until top of
adjusting screw (6) protrudes from top of
spring chamber (2). NOTE: Care should
be taken when holding and rotating the
adjusting screw (6) so the quad ring (31)
and backup ring (32) are not inadvertently
nicked or torn. Grasp top of adjusting
screw (6) and turn CCW until rotation
stops (see CAUTION C). See Figure 1.
d. Loosely install lock nut (7) and closing cap
(28).
7. Inspect pressure plate (3) for defects due to
over-pressurization. Replace if defective.
8. Clean all parts to be re-used according to
owner's procedures.
9. Place first o-ring (30) on body (1) and lubricate
with a lightweight multi-purpose grease.
Position body spacer (24) on body with match
marks aligned. Place pusher plate (11) on body
spacer (24) and check for vertical movement.
NOTE: The vertical movement should be free
and unobstructed as the pusher plate (11) is
pushed down and the lower piston spring (17)
contracts and expands. If movement is not
free, go to Subsection C following to inspect
the inner trim parts.
10. Place second o-ring (30) on body spacer (24)
and lubricate with lightweight multi-purpose
grease. Position diaphragm (12) on body
spacer (24) inside of o-ring (30).
11. Visually center the pressure plate (3) on
diaphragm (12). Place range spring (14) onto
retainer hub of pressure plate (3).
12. Place multi-purpose, high temperature grease
into depression of spring button (4) where
adjusting screw (6) bears. Set spring button (4)
onto range spring (14); ensure spring button
(4) is laying flat.
13. Using "NEW" studs (34,35) and nuts (9) (see
CAUTION D), thread a nut onto each stud
approximately 1.25" (32 mm). Drop the studs
(34,35) with nuts (9) through the holes in
spring chamber (2). (This will assist in keeping
the spring chamber (2) centered on body
(1) and prevent parts from moving during re-
assembly).
Using the "match marks" made in Step 3 as a
guide, replace spring chamber (2) onto body
spacer (24). Thread on lower nuts (9) and
tighten by hand. Adjust length of studs (34,35)
by using the top nut (9) so that there are at least
3 to 4 threads protruding from the lower nut.
Torque body flange hardware (9,23,34,35)
using small increments in a 180° alternating
pattern until flange mating surfaces of body
(1), body spacer (24) and spring chamber
(2) are metal to metal. This creates a "fixed
compression" on the diaphragm (12) and
o-ring (30) seals. Recommended torque
values are listed in Table 1.
TABLE 1
Body Size
in. (DN)
Item
No.
Thread
Size
Torque Values
Ft-lbs (N-m)
1/2"-1" (15-25) 9,23,34 3/8"-24 35-40 (47-54)
1-1/2" (40) 9,23,34,35 7/16"-20 55-60 (75-81)
14. With locknut (7) tight against closing cap
(28), turn closing cap (28) CW until tension is
applied to range spring (14).
15. Proceed to Section D. for bench test.
C. Trim Replacement:
NOTE: Do not release tension on range spring
(14). (Only necessary when removing spring
chamber). The range spring (14) tension
keeps pusher plate (11) in alignment and
assures proper fit upon replacement of trim.
1. Install body (1) in a vise with the body cap (5)
on top and spring chamber (2) downwards.
2. Loosen and remove body cap (5). NOTE:
Piston spring (17) may stick in body cap (5)
when removing.
3. Remove piston spring (17), piston (15) and
cylinder (16). Inspect parts for excessive
wear, especially at piston (15) seat surface.
Ensure there are no nicks or foreign particles
embedded in the piston (15) TFE seat.
Replace piston w/ TFE seat (15) if necessary.
Inspect the backup ring (27) and quad ring (26)
on piston (15). Replace rings if worn, nicked,
or depressed.
4. Remove body cap O-ring (25). Clean
contacting surfaces of body (1) and body cap
(5). Be careful not to scratch either surface.
Inspect inside surface of the body cap for
scratches or nicks. These could result in
leakage past the quad ring (26) and backup
ring (27). If worn or scratched replace body
cap (5).

IOM-HP-S-DIFF 5
5. Clean debris from within the regulator body
(1) cavity. Make certain the old cylinder gasket
(18) is cleaned out of the body (1) recess.
Clean all parts to be reused according to
owner's procedures.
6. Reinstall a new cylinder gasket (18). Press
firmly and evenly into place using the cylinder
(16). Do not use a “homemade” cylinder
gasket. Pipe sealant may be lightly coated to
the gasket (18) surfaces prior to installation.
Inspect to see that cylinder gasket (18) is
completely pressed into place and cylinder
(16) is centered with body cap (5) opening.
7. Install a new back up ring (27) and quad ring
(26) on piston (15). Make certain the teflon
back up ring (27) will insert the body cap (5)
first, before the quad ring (26) (See Figure 3).
Make sure the quad ring (26) is on straight with
no twist.Use a good grade lightweight grease
on both ring seals (26,27). Slide piston (15)
into cylinder (16).
8. Place piston spring (17) into the cavity of the
piston (15).
9. Insert new body cap o-ring (25) into groove of
body cap (5). Use a good grade lightweight
grease on body cap o-ring (25). Use pipe
thread sealant applied to the body cap (5)
threads. Screw body cap (5) into body (1).
Impact until body cap (5) is metal to metal
against body (1) at the body cap (5) shoulder.
D. Bench test for suitable operation (Test Fluid:
Air or compressed gas).
NOTE: Regulators are not tight shutoff devices.
Even if pressure builds up beyond setpoint, a
regulator may or may not develop tight shutoff.
1. Check for internal trim leakage: With No.
1 shut-off valve closed and No. 2 shut-off
valve cracked open, turn on inlet operating
pressure. Follow instructions from SECTION
IV-2. and set a differential pressure of 20
psig (1.4 Barg) in the downstream line (No.
2 Gauge). Close No. 2 shut-off valve and
check for tight shutoff. NOTE: Seat leakage
not to exceed 15 bubbles per minute. Do
not allow excessive buildup if seat leakage
exists (crack open No. 2 shut-off valve to
prevent buildup). If seat leakage is excessive,
proceed with the following steps to determine
location of leak:
a. Close No. 1 shut-off Valve.
b. Turn off inlet operating pressure (P1).
c. Remove entire topworks per SECTION
VI-B., steps 1-5.
d. Turn inlet operating pressure (P1) on.
e. Spray liquid leak detector in the space
between cylinder (16) and body (1) to
check for cylinder gasket (18) leakage.
f. Pour a few drops into recess along piston
post (15) to check for seat leakage.
g. Fill the recess to check for quad ring (26)
leakage.
Once location of leak is detected, proceed
to SECTION VII-6 for Cause/Remedy and
SECTION VI-C. for internal trim replacement.
After leak is remedied, proceed to SECTION
VI-B., steps 8-15 to reassemble topworks.
2. Check regulator performance: With Step No.
1 conditions met, open and close No. 2 shut-
off valve to check regulator's performance for
smoothness and repeatability.
3. Proof test to check for external leakage:
a. Build inlet pressure to 1-1/2 times
maximum outlet pressure; but not to
exceed 1-1/2 times the Max. Outlet and
Spring Chamber Pressure Rating (See
HP-S-DIFF TB, Table 2). Close No. 2 shut-
off valve and crack open No. 1 shut-off
valve until full inlet pressure exists in the
spring chamber (2) and downstream line
(No. 2 gauge will register same pressure
as No. 1 gauge).
b. 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. To relieve all pressures simultaneously
(preventing diaphragm (12) damage
due to excessive ∆P across diaphragm
(12)), crack open No. 2 shut-off valve and
shut off inlet pressure. This will uniformly
bleed off all pressure contained within the
regulator.
4. Return to Section II for Installation and Section
IV for Startup.
Figure 2: Recommended Bench Test
Piping Schematic for HP-1+6+S

IOM-HP-S-DIFF
6
SECTION VII
VII. TROUBLE SHOOTING GUIDE
Possible Cause Remedy
A. Oversized regulator; inadequate rangeability. A1.
A2.
A3.
A4.
A5.
Check actual flow conditions, resize regulator for minimum and
maximum flow.
Increase flow rate.
Decrease regulator pressure drop; decrease inlet pressure by placing
a throttling orifice in inlet piping union.
Install next step higher range spring. Contact factory.
Before replacing regulator, contact factory.
B. Worn piston; inadequate guiding. B. Replace trim.
C. Weakened/broken piston spring. C. Replace piston spring. Determine if corrosion is causing the failure.
If so, consider NACE acceptable trims.
D. Unstable loading pressure. D. Stabilize loading pressure; i.e. pump, control valve, etc.
1. Erratic operation; chattering.
Possible Cause Remedy
A. Regulator undersized; A1.
A2.
Confirm by opening bypass valve together with regulator.
Check actual flow conditions, resize regulator; if regulator has
inadequate capacity, replace with larger unit.
B. Plugged trim. B. Remove trim and check for plugged holes in cylinder.
C. Incorrect range spring (screwing in adjusting screw CW does not
bring pressure up to proper level).
C. Replace range spring with proper higher range. Contact factory.
D. Too much proportional band (droop); outlet (P2) pressure droops
below load pressure (PLOAD).
D1.
D2.
Review Proportional Band (droop) expected.
Contact factory.
E. Restricted diaphragm movement. E. Ensure no moisture in spring chamber at temperatures below freeze
point.
2. Downstream pressure will not reach desired setting.
Possible Cause Remedy
A. Normal-life diaphragm failure. A1.
A2.
Replace diaphragm.
Check actual flow conditions, resize regulator; if regulator has
inadequate capacity, replace with larger unit.
B. Abnormal short-life diaphragm failure. B1.
B2.
B3.
B4.
B5.
Can be caused by excessive chattering. See VII - 1. to remedy
chatter.
Can be caused by corrosive action. Consider NACE acceptable
trims.
Ensure not subjecting to over-temperature conditions.
Downstream outlet (P2) pressure buildup occurring that overstresses
diaphragms. Protect with safety relief valve.
Inlet (P1) pressure valve is shutoff while loading (PLOAD) pressure
is still on.
3. Leakage through body spacer vent hole, or mixing of fluids.
Possible Cause Remedy
A. Regulator not closing tightly. A1.
A2.
Inspect the seating. Replace if depressed, nicked or embedded
with debris.
Inspect guides in body cap. If damaged, replace body cap and/or
piston.
B. Downstream block. B. Check system; isolate (block) flow at regulator inlet - not outlet.
Relocate regulator if necessary.
C. No pressure relief protection. C. Install safety relief valve, or rupture disc.
D. Restricted diaphragm movement. D1. Ensure no moisture in spring chamber at temperatures below
freeze point.
4. Excessive pressure downstream.

IOM-HP-S-DIFF 7
SECTION VIII
Possible Cause Remedy
A. Plugged body spacer vent hole. A. Clean vent opening.
B. Plugged piston balance port. B. Remove trim and clean balance port.
C. Fluid too viscous. C. Heat fluid. Contact factory.
5 Sluggish operation.
6. Excessive seat leakage.
Possible Cause Remedy
A. Foreign matter on seating surface, erosion of seating surface. A. Inspect and replace damaged parts.
B. Quad ring/backup ring damaged, scratched body cap. B. Inspect and replace damaged parts.
C. Cylinder gasket damaged. C. Inspect and replace damaged part.
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
("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.
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.

IOM-HP-S-DIFF
8
Repair
Item No. Description Parts
1 Body
2 Spring Chamber
3 Pressure Plate
4 Spring Button
5 Body Cap
6 Adjusting Screw
7 Lock Nut
9 Flange Stud Nut
11 Pusher Plate
12 Diaphragm
14 Range Spring
Repair
Item No. Description Parts
15 Piston w/ TFE Seat
16 Cylinder
17 Piston Spring
18 Cylinder Gasket
23 Cap Screw
24 Body Spacer
25 Body Cap O-Ring
26 Quad Ring
27 Backup Ring
28 Closing Cap
30 O-ring (2 req'd)
31 Quad Ring
32 Backup Ring
34 Stud
35 Stud
FIGURE 3
Model HP-1+6+S
2
6
28
34 35
9
3
24
11
7
31 32
4
14
23
12
30
16
1
18
15 26 27
17
25
5
1/2" (DN15) female NPT
Loading Connection.
31
32
6
27
26
15
*
*
*
*
*
*
*
*
*
*
*
*
*
Seal Welded per ASME
BPVC Code Section IX
18
16
*
*
TFE
SEAT
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
**
*
*
**

IOM-HP-S-DIFF 9
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
NOTICE
Only for Product Codes wherein hazard
category ATEX has been selected.

IOM-HP-S-DIFF
10
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-HP-S-Diff
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]
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.
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.