cashco HP Instruction manual

INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM) IOM-HP
12-16
MODEL HP
PRESSURE REDUCING REGULATOR
SECTION I
I. DESCRIPTION AND SCOPE
The Model HP is a heavy duty, high pressure reducing regulator used to control downstream (outlet or P2) pressure.
Sizes are 1/2", 3/4", 1" and 1-1/2" (DN15, 20, 25 and 40). With proper trim utilization, the unit is suitable for liquid and
gaseous service. Refer to Technical Bulletin HP-TB for design conditions and selection recommendations. NOT FOR
STEAM SERVICE.
SECTION II
II. INSTALLATION
1. An inlet block valve should always be installed.
2. If service application is continuous such that shutdown
is not readily accomplished, it is recommended that
an inlet block valve, outlet block valve, and a manual
bypass valve be installed.
3. Pipe unions should be installed to allow removal from
piping.
4. An outlet pressure gauge should be located
approximately ten pipe diameters downstream, and
within sight.
5. All installations should include a downstream relief
device if the inlet pressure could exceed the pressure
rating of any downstream equipment or the maximum
outlet pressure rating of the unit.
6. Clean the piping of all foreign material including chips,
welding scale, oil, grease and dirt before installing the
regulator. Strainers are recommended.
7. In placing thread sealant on pipe ends prior to
engagement, ensure that excess material is removed
and not allowed to enter the regulator upon startup.
8. Flow Direction: Install so the flow direction matches
the arrow cast on the main regulator body.
9. Basic Regulator - (Refer to Figure 1): Regulator may
be rotated around the pipe axis 360°. Recommended
position is with spring chamber vertical upwards. Orient
such that the spring chamber vent hole does not collect
rainwater or debris.
10. Regulators are not to be direct buried underground.
11. For insulated piping systems, recommendation is to not
insulate regulator.
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 damage non-metallic parts if
not removed. NOTE: This does 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.
ISO Registered Company

IOM-HP2
SECTION III
* 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
to a regulator being interrupted (automatically or manually).
IV. STARTUP
1. Start with the block valves closed. A bypass valve may
be used to maintain outlet pressure in the downstream
system without changing the following steps.
2. Relax the range spring by turning the adjusting screw
counter clockwise (CCW) a minimum of three (3) full
revolutions. This reduces the outlet (downstream)
pressure set point.
3. If it is a “hot” piping system, and equipped with a bypass
valve, slowly open the bypass valve to pre-heat the
system piping and to allow slow expansion of the
piping. Closely monitor outlet (downstream) pressure
via gauge to ensure not over-pressurizing. NOTE: If no
bypass valve is installed, extra caution should be used
in starting up a cold system; i.e. do everything slowly.
SECTION V
V. SHUTDOWN
1. On systems with a bypass valve, and where system
pressure is to be maintained as the regulator is shut
down, slowly open the bypass valve while closing
the inlet (upstream) block valve. Fully close the inlet
(upstream) block valve. (When on bypass, the system
pressure must be constantly observed and manually
regulated. Close the outlet (downstream) block valve.
2. If the regulator and system are to both be shut down,
slowly close the inlet (upstream) block valve. Close the
outlet (downstream) valve only if regulator removal is
required.
4. Crack open the outlet (downstream) block valve.
5. Slowly open the inlet (upstream) block valve observing
the outlet (downstream) pressure gauge. Determine if
the regulator is flowing. If not, slowly rotate the regulator
adjusting screw clockwise (CW) until flow begins.
6. Continue to slowly open the inlet (upstream) block valve
until fully open.
7. Continue to slowly open the outlet (downstream) block
valve, especially when the downstream piping system
isn't pressurized. If the outlet (downstream) pressure
exceeds the desired pressure, close the block valve
and go to Step 2, then return to Step 4.
8. When flow is established steady enough that the outlet
(downstream) block valve is fully open, begin to slowly
close the bypass valve if installed.
9. 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 outlet pressure, or
CCW to reduce outlet pressure.
10. Reduce system flow to a minimum level and observe set
point. Outlet pressure will rise from the set point of Step
9. The maximum rise in outlet pressure on decreasing
flow should not exceed the stated upper limit of the
range spring by greater than 10%; i.e. 400–750 psig
(27.5 –51.7 Barg) range spring, at low flow the outlet
pressure should not exceed 825 psig (56.8 Barg), if it
does, consult factory.
III. PRINCIPLE OF OPERATION
1. Movement occurs as pressure variations register
on the diaphragm. The registering pressure is the
outlet, P2, or downstream pressure. The range spring
opposes diaphragm movement. As outlet pressure
drops, the range spring pushes the diaphragm down,
opening the port; as outlet pressure increases, the
diaphragm pushes up and the port opening closes.
2. A complete diaphragm failure will cause the regulator
to fail open.
SECTION IV
CAUTION
The maximum outlet pressure is listed on the
nameplate as the upper range spring pressure
level, and is the recommended "upper operative
limit" for the sensing diaphragm. Higher pressures
could damage the diaphragm. Refer to HP-TB, Table
5, for “emergency over-pressure level”. NOTE:
Inlet pressure and outlet pressure ratings are at
different levels. (Field hydrostatic tests frequently
destroy diaphragms. DO NOT HYDROSTATIC TEST
THROUGH AN INSTALLED UNIT; ISOLATE FROM
TEST.).
CAUTION
Do not walk away and leave a bypassed regulator
unattended.

IOM-HP 3
SECTION VI
VI. MAINTENANCE
2. Relax range spring (14) by turning adjusting screw
(6) CCW until removed from spring chamber (2).
3. Draw or embed a match mark between body
casting (1) and spring chamber casting (2) along
flanged area.
4. Remove all diaphragm flange nuts (9) and bolts
(8, 23).
5. Remove spring chamber (2), range spring
(14), spring button (4), pressure plate (3),
diaphragm(s) (12), and diaphragm gasket (13),
for metal diaphragm (no diaphragm gasket (13) for
composition diaphragm). NOTE: For units with
spring ranges 120-225 psig (8.27 - 15.5 Barg) and
higher, also remove the thrust bearing (21) and
bearing washer (22).
6. Remove pusher plate (11) and inspect for a fit
which limits its travel to a vertical direction. Wear
will show as excessive wobble in pusher plate
NOTE: Never replace bolting (8 & 9) (23) with just
any bolting if lost. Bolt heads and nuts are marked
with specification identification markings. Use only
proper grades as replacements.
12. Reinstall adjusting screw (6) with locknut (7).
13. Pressurize with air and soap solution test around
bolting (8 & 9) (23), body (1) and spring chamber
(2) for leakage. Ensure that an outlet pressure is
maintained during this leak test of at least mid-
range spring level; i.e. 120-255 psig (8.27-15.5
Barg) range spring, 173 psig (11.9 Barg) test
pressure minimum.
(11). If apparent, recommend trim removal and
inspection; go to Sub-section C or D following.
Reinstall pusher plate (11).
7. Inspect pressure plate (3) to ensure no deformation
due to over-pressurization. If deformed, replace.
8. Clean body (1) and diaphragm flange. NOTE: On
regulators originally supplied as “oxygen clean”,
Option-55, maintenance must include a level of
cleanliness equal to Cashco's cleaning standard
#S-1134. Contact factory for details.
9. Place diaphragm gasket (13) on body (1) flange.
Positiondiaphragm(s)(12)intoplace.NOTE: Refer
to the quantity of diaphragms (12) incorporated in
the bill of materials listing. Depending on the outlet
pressure level; multiple metal diaphragms may be
“stacked”. Visually center pressure plate (3) on
diaphragm(s) (12), and set range spring (14) onto
retainer hub of pressure plate (3).
10. Place multi-purpose, high temperature grease into
depression of spring button (4) where adjusting
screw bears. Set spring button (4) onto range
spring (14); ensure spring button is laying flat.
NOTE: For units with range springs 120-225 psig
(8.27-15.5 Barg) and higher, position spring button
(4), thrust bearing (21) and bearing washer (22) on
top of range spring (14).
11. Aligning matchmarks, place spring chamber (2)
over the above stacked parts. Install all bolts (8),
(23) and nuts (9) by hand tightening. Mechanically
tightening bolting in a cross pattern that allows
spring chamber (2) to be pulled down evenly.
Recommended torque values are as follows:
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 1 for the basic regulator and Figure
2 for a blowup of the balanced trim.
B. Diaphragm Replacement:
1. Securely install the body (1) in a vise with the spring
chamber (2) directed upwards.
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.
WARNING
SPRING UNDER COMPRESSION. Prior to removing
diaphragm flange bolts, relieve spring compression
by backing out the adjusting screw. Failure to do so
may result in flying parts that could cause personal
injury.
Regulator Size Bolt Size Metal Diaph. Comp. Diaph.
1/2", 3/4" & 1"
(DN15, 20 & 25) 3/8-24 30 Ft-lbs 25 Ft-lbs
1-1/2" (DN40) 7/16-20 50 Ft-lbs 30 Ft-lbs

IOM-HP4
E. Special Instructions for Diaphragm Replacement:
1. For the Option -1+6 Differential Construction,
reassemble the diaphragm subassembly in Sub-
Section B. Step 9.
2. For metal diaphragm(s) (12) only, install a second
diaphragm gasket (13) on the top side of the
diaphragm (4). NOTE: Clean the diaphragm flange
area of the spring chamber (2) thoroughly before
assembly.
3. Utilize a new lock nut seal (22) when installing the
adjusting screw (13) and locknut (14).
4. Install new closing cap gasket (21), reinstall closing
cap (20).
D. Trim Replacement (For Composition Seated Units):
Follow the same steps as listed under “Trim
Replacement for Metal Seated Units”, except for the
following guidelines:
1. When inspecting parts for excessive wear (C.3)
ensure there are no foreign particles embedded in
the TFE seat. Inspect for nicks. Inspect the backup
ring (27) and quad ring (26) on piston post.
2. After removing the body cap (5) (C.4), inspect the
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 the body cap (5).
3. Remove the body cap O-ring (25) and clean
contacting surface of body (1).
C. Trim Replacement (For Metal Seated Units):
1. Install body (1) in a vise with the body cap (5) on
top and the body (1) flange downwards.
2. Loosen body cap (5) with a hex head wrench with
a lever length of at least 15 inches (381 mm). The
wrench should be rapped with a hammer to loosen.
Remove body cap (5).
3. Remove piston spring (17), and piston (15.1) and
cylinder (15.2). Inspect parts for excessive wear,
especially at seat surfaces. Replace if worn, nicked
or depressed.
4. Clean flat mating surfaces of body (1) to body
cap (5) shoulder. Be careful not to scratch either
surface.
5. Clean debris from within the regulator body (1)
cavity. Clean parts to be reused. NOTE: On
regulators originally supplied as "oxygen clean",
Options-55, maintenance must include a level of
cleanliness equal to Cashco's cleaning standard
#S-1134. Contact factory for details.
6. Reinstall a new cylinder gasket (18). Press firmly
and evenly into place using the cylinder (15.2).
Remove the cylinder (15.2) and inspect the
pressed in cylinder gasket (18). Do not use a
“homemade” cylinder gasket. Pipe sealant may
be lightly coated to the gasket surfaces prior to
installation, except when utilizing Option-55.
7. Reinstall the cylinder (15.2), observing that when
finally setting, the cylinder (15.2) appears to be
concentrically located within the body cap (5)
opening.
8. Slide the piston (15.1) slowly into place, ensuring
that the piston (15.1) post slides into the female
groove of the pusher plate (11).
9. Place piston spring (17) into the cavity of the piston
(15.1).
10. Use pipe thread sealant applied to the body cap (5)
threads. Screw body cap (5) into body (1). When
body cap (5) is fully down against body (1) at the
body cap shoulder, use the wrench with 15" (381
mm) lever handle and a hammer to impact the body
cap (5) into the body (1).
11. Bench test for suitable operation. NOTE:
Regulators are not tight shutoff devices. Even if
pressure builds up beyond setpoint, a regulator
may or may not develop bubble tight shutoff. In
general, tighter shutoff can be expected with a
composition seat.
12. Soap solution test around body cap (5) and
body (1) for leakage. Test pressure should be a
minimum of 100 psig (6.9 Barg) at the inlet.
CAUTION
When piston (15) assemblies are used with
compositionseats,Cashco,Inc.doesnotrecommend
attempting to remove the composition seat, as it is
retained by the piston's post being force pressed
into the lower cylinder section, and the outer (OD)
edge of the composition seat is retained by the
piston's thinned wall being forcefully crimped into
the composition seat material (bent over and into). If
composition seat is damaged, replace entire piston
assembly.
CAUTION
Option-1+6containssingle diaphragmconstruction.
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.

IOM-HP 5
SECTION VII
VII. TROUBLE SHOOTING GUIDE
1. Erratic operation; chattering.
Possible Causes Remedies
A. Oversized regulator; inadequate rangeability. A1. Check actual flow conditions, resize regulator for minimum and maximum flow.
A2. Increase flow rate.
A3. Decrease regulator pressure drop; decrease inlet pressure by placing a throttling
orifice in inlet piping union.
A4. Install next step higher range spring. Contact factory.
A5. 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, then consider
NACE acceptable trims.
2. Downstream pressure will not reach desired setting.
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.
A3. Decrease regulator pressure drop; decrease inlet pressure by placing a throttling
orifice in inlet piping union.
A4. Install next step higher range spring. Contact factory.
A5. Before replacing regulator, contact factory.
B. Plugged trim. B. Remove trim and check for plugged holes in cylinder.
C. Incorrect range spring (screwing in CW of
adjusting screw does not allow bringing
pressure level up to proper level).
C. Replace range spring with proper higher range. Contact factory.
D. Too much proportional band (droop). D1. Review P.B. (droop) expected.
D2. Contact factory.
E. Restricted diaphragm movement. E. Ensure no moisture in spring chamber at temperatures below freeze point. Ensure no
dust or debris entering vent opening. If rainwater or debris can enter, reorient spring
chamber.
3. Leakage through the spring chamber vent hole.
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. Can be caused by corrosive action. Consider alternate diaphragm material.
B3. For composition diaphragms, ensure not subjecting to over-temperature conditions.
B4. Downstream (outlet) pressure buildup occurring that overstresses diaphragms. Relocate
regulator or protect with safety relief valve.
4. Excessive pressure downstream.
Possible Causes Remedies
A. Regulator not closing tightly. A1. Inspect the seating. Clean and lap metal seat surfaces; replace if lapping does not
remedy. If composition seats are depressed, nicked or embedded with debris, replace
trim.
A2. Inspect guides in body cap (balanced trim). 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. D. Ensure no moisture in spring chamber at temperatures below freeze point. Ensure no
dust or debris entering vent opening. If rainwater or debris can enter, re-orient regulator.

IOM-HP6
SECTION VIII
5. Sluggish operation.
Possible Causes Remedies
A. Plugged spring chamber vent. 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.
6. Excessive Seat Leakage.
Possible Causes Remedies
A. Foreign matter on seating surface, erosion of
seating surface, scratched body cap.
A. Inspect and replace damaged parts.
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 7
FIGURE 1
Model HP – Metal Seat
Item Repair Parts
No. Description Kit A Kit B
1 Body
2 Spring Chamber
3 Pressure Plate
4 Spring Button
5 Body Cap
6 Adjusting Screw
7 Sealing Lock Nut * **
8 Flange Bolt
9 Flange Bolt Nut
10 Name Plate
11 Pusher Plate
12 Diaphragm * **
14 Range Spring
15 Piston/Comp Seat **
15.1 Piston - Metal **
15.2 Cylinder - Metal **
16 Cylinder – Comp **
17 Piston Spring **
18 Cylinder Gasket * **
21 Thrust Bearing
22 Bearing Washer
23 Flange Bolt (No Nut)
25 Body Cap O-Ring * **
26 Quad Ring * **
27 Backup Ring * **
Items Not Shown
13 Diaphragm Gasket used only *
with metal diaphragm(s) ***
24 Diaphragm Ring (1-1⁄2" size only)
28 Closing Cap
29 Closing Cap Gasket * **
FIGURE 2
Balanced Composition Seat

IOM-HP8
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 9
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
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.