Emerson ENARDO 860 Series User manual

Enardo 860 and 960 Series Spring-Loaded
Pressure/Vacuum Relief Valve (ATEX Approved)
Table of Contents
Introduction..................................................................1
Specifications .............................................................. 2
Product Identification and Marking .............................. 4
Principle of Operation.................................................. 4
Installation ...................................................................5
Maintenance................................................................9
Weight Information .................................................... 11
Valve Repair .............................................................. 11
▲ WARNING
Failure to follow these instructions or
to properly install and maintain this
equipment could result in an explosion,
re and/or chemical contamination
causing property damage and personal
injury or death.
Fisher™ spring-loaded pressure/vacuum
relief valve must be installed, operated
and maintained in accordance with
federal, state and local codes, rules
and regulations, and Emerson Process
Management Regulator Technologies
Tulsa, LLC (Emerson) instructions.
Failure to correct trouble could result in
a hazardous condition. Call a qualied
service person to service the unit.
Installation, operation and maintenance
procedures performed by unqualied
person may result in improper adjustment
and unsafe operation. Either condition may
result in equipment damage or personal
injury. Only a qualied person shall install
or service the spring-loaded pressure/
vacuum relief valve.
Figure 1. Enardo Model 860 Spring-Loaded Pressure/
Vacuum Relief Valve
Figure 2. Enardo Model 960 Spring-Loaded Pressure/
Vacuum Relief Valve
Introduction
Scope of the Manual
This Instruction Manual provides instructions for
installation, maintenance and parts ordering information
for the Enardo 860 and 960 Series spring-loaded
pressure/vacuum relief valve (SL-PVRV).
Instruction Manual
D103814X012
February 2022
Enardo 860 and 960 Series
Outside North America Only

Specications
The Specications section on this page provides specications for the Enardo 860 and 960 Series spring-loaded
pressure/vacuum relief valve. Specication is stamped on the nameplate attached to the relief valve. Refer to
Product Identication and Marking section for the nameplate details.
Available Construction
See Figure 3
Inlet Connection Sizes
2 through 6 in. / 50 through 150 mm
Pressure Ranges(1)(2)
0.5 to 15.0 psi
0.5 to 32.0 oz./sq. in.
1.0 to 55.0 in. w.c.
2.0 to 138 mbar
Vacuum Pressure Ranges(1)(2)
0.5 to 15.0 psi
0.5 to 32.0 oz./sq. in.
1.0 to 55.0 in. w.c.
2.0 to 138 mbar
Construction Materials
Housing: Aluminum, Stainless steel or Carbon steel
Seat / Pallet: Polyphenylene Sulde (PPS) or 316
Stainless steel (standard above 5 psi)
Pallet Seal: Buna-N, FEP Teon®or Viton®
Hardware: Zinc plated carbon steel or Stainless steel
Weights: Zinc plated carbon steel, Stainless steel
or Lead
Gaskets: Buna-N, Teon®or Viton®
Certication
EN IEC 60079-0:2018
EN IEC 60079-11:2012
EN ISO 80079-36:2016
EN ISO 80079-37:2016
1. The pressure limits in this Instruction Manual and any applicable standard or code limitation should not be exceeded.
2. Pressure or vacuum setting has an increment of 0.5 psi, 0.5 oz./sq. in., 0.5 in. w.c. or 2.2 mbar.
Teon®and Viton®are marks owned by E. I. du Pont de Nemours and Co.
Figure 3. Pressure/Vacuum Relief Valve Model Number
ENARDO MODEL 860 SPRING-LOADED PRESSURE/VACUUM RELIEF VALVE MODEL NUMBER
ENARDO MODEL 960 SPRING-LOADED PRESSURE/VACUUM RELIEF VALVE MODEL NUMBER
Inlet
Connection
Size
(2 through
6 in.)
Inlet
Connection
Size
(2 through
6 in.)
Outlet
Connection
Size
(3 through
8 in.)
Housing Material
1 = Aluminum
4 = 316 Stainless
Steel
5 = Carbon Steel
Housing Material
1 = Aluminum
4 = 316 Stainless
Steel
5 = Carbon Steel
Pallet and Seat
Material
1 = PPS Polyphenylene
Sulde (max 5 psi)
2 = 316 Stainless steel
(max 14.99 psi)
Pallet and Seat
Material
1 = PPS Polyphenylene
Sulde (max 5 psi)
2 = 316 Stainless steel
(max 14.99 psig)
Pallet Seal
Material
1 = FEP
2 = Nitrile (NBR)
3 = Fluorocarbon
(FKM)
Pallet Seal
Material
1 = FEP
2 = Nitrile (NBR)
3 = Fluorocarbon
(FKM)
Body/Seat/Lid Seal
Material
1 = PTFE Body and
FEP Seat/Lid
2 = Nitrile (NBR)
3 = Fluorocarbon
(FKM)
Body/Seat/Lid Seal
Material
1 = PTFE Body and
FEP Seat/Lid
2 = Nitrile (NBR)
3 = Fluorocarbon (FKM)
Pressure Units
z = oz./sq.in.
n = in. w.c.
mm = mm w.c.
mb = mbar
p = psi
Pressure Units
z = oz./sq.in.
n = in. w.c.
mm = mm w.c.
mb = mbar
p = psi
Vacuum Units
z = oz./sq.in.
n = in. w.c.
mm = mm w.c.
mb = mbar
p = psi
Vacuum Units
z = oz./sq.in.
n = in. w.c.
mm = mm w.c.
mb = mbar
p = psi
Pressure Setting
Maximum = 14.99 psig /
1034 mbarg
Pressure Setting
Maximum = 14.99 psig /
1034 mbarg
Vacuum Setting
Maximum = 14.99 psig /
1034 mbarg
Vacuum Setting
Maximum = 14.99 psig /
1034 mbarg
Weight Material
C = Carbon Steel
Zinc-Plated
S = 316 Stainless steel
L = Lead
Weight Material
C = Carbon Steel
Zinc-Plated
S = 316 Stainless steel
L = Lead
Options
0 = No Options
F = Flat Face Flange (standard for Aluminum)
R = Raised Face Flange (standard for CS, DI, SS)
X = Epoxy
Options
0 = No Options
F = Flat Face Flange (standard for Aluminum
R = Raised Face Flange (standard for CS, DI, SS)
X = Epoxy
ENARDO 860 -
ENARDO 960 -
X - - /
- - /
- -
/ -
2
Enardo 860 and 960 Series
Outside North America Only

Product Description
The Enardo 860 and 960 Series spring-loaded
pressure/vacuum relief valves are designed to handle
higher pressure settings than standard dead weight-
loaded valves.The Enardo 860 Series is used for pipe-
away aplications while Enardo 960 Series is used for
vent-to-atmosphere applications. Fisher spring-loaded
line are designed for pressures up to 15 psig for tanks
with higher maximum allowable working pressures.
With proper installation, usage and preventative
maintenance, the Enardo 860 and 960 Series can
supply many years of pressure/vacuum relief with
continuous sealing abilities that exceed the most
stringent industry standards (1 SCFH at 90% set
point per valve). Spring-loaded pressure/vacuum
relief valves have the option of weight-loaded pallets
in either the vacuum or pressure portion of the valve.
The following is the list of the available spring-loaded
pressure/vacuum relief valve models. See Figure 4.
• Enardo Model 860:
Pressure/Vacuum Relief Valve - Pipe-Away
• Enardo Model 861: Top Mount Pressure or Side
Mount Vacuum Relief Valve - Pipe-Away
• Enardo Model 960:
Pressure/Vacuum Relief Valve - Vent-to-Atmosphere
• Enardo Model 961:
Pressure Relief Valve - Vent-to-Atmosphere
• Enardo Model 962:
Top Mount Vacuum Relief Valve - End of Line
• Enardo Model 963: Side Mount Vacuum Relief Valve
Figure 4. Enardo 860 and 960 Series Spring-Loaded Pressure/Vacuum Relief Valve Available Models
ENARDO MODEL 860 ENARDO MODEL 861 ENARDO MODEL 960
ENARDO MODEL 961 ENARDO MODEL 962 ENARDO MODEL 963
3
Enardo 860 and 960 Series
Outside North America Only

Product Identication and Marking
Hazardous Locations
Fisher™ spring-loaded pressure/vacuum relief valves
are available with outer housings of carbon steel,
stainless steel or aluminum, as indicated in Figure 5.
Nameplate
A nameplate is attached to the valve and contains the
following information:
• Model Number – Ex. 860- 3X4-4211
• Conn. Flange Size and Rating – Ex. 3 in.
• Serial Number
• Tag Number (Optional)
• Notied Body Number – Ex. 2460
• Cat. No. (Category Number) –
Ex. -
Category 1 - Stainless steel, Carbon steel or
Coated Aluminum vents
Category 2 - Uncoated Aluminum vents
• Date – Date of Manufacture
• Certicate – Ex. PRESAFE 17 ATEX 10273X
• Pressure
- Setting – Ex. Z4.0
- Flow Rate SCFH (Air) – Ex. 55000
• Vacuum
- Setting – Ex. Z0.5
- Flow Rate SCFH (Air) – Ex. 25000
Principle of Operation
The Fisher spring-loaded pressure/vacuum relief valveThe Fisher spring-loaded pressure/vacuum relief valve
maintains a tight seal, until system pressure or vacuummaintains a tight seal, until system pressure or vacuum
exceeds the set pressure of the valve. Set pressure isexceeds the set pressure of the valve. Set pressure is
established by the force of a spring or a set of multipleestablished by the force of a spring or a set of multiple
springs acting on the valve pallet. When the systemsprings acting on the valve pallet. When the system
pressure is above the set pressure, the pallet starts topressure is above the set pressure, the pallet starts to
lift, breaking the seal between the seat and pallet. Thislift, breaking the seal between the seat and pallet. This
allows vapors to pass through the valve orice and allows vapors to pass through the valve orice and
relieve pressure buildup. The valve reseals upon reliefrelieve pressure buildup. The valve reseals upon relief
and remains sealed.and remains sealed.
Relieving vapors near the set pressure in a continuous
manner may cause the pallet to utter or oscillate inside
the valve chamber. This is common to products of this
model. Operating the valve with utter or oscillation may
cause premature valve damage or wear over time. The
utter zone typically begins at the set point and ends at
the ow rate associated with 10% overpressure. The
Fisher Valve Sizing Program displays the utter zone.
Contact your local Sales O󰀩ce with any questions or
additional assistance.
Figure 5. ATEX Certified Markings
OUTER HOUSING OF STAINLESS STEEL,
CARBON STEEL OR COATED ALUMINUM
OUTER HOUSING OF UNCOATED ALUMINUM
II 1 G Ex h IIC T6 Ga
II 2 G Ex h IIC T6 Gb
4
Enardo 860 and 960 Series
Outside North America Only

2. Orient valve in desired direction. Enardo
Models 860 and 861 require the pipe-away
connection ange to be properly oriented before
the base is bolted down.
3. After the valve has been properly aligned, install nuts
and bolts. Tighten the bolts down in a cross-hatched
pattern. Ensure the valve is securely fastened.
Installation
△ CAUTION
Ensure the tank is at atmospheric pressure
before opening. A pressure build-up inside
the tank can cause a spray to be emitted
from the valve if opened under pressure.
Springs are energy storage devices and
are dangerous if handled improperly.
Never loosen any nuts or cap screws
until all spring preload has been relieved.
Always use appropriate safety equipment
including safety glasses or shields any
time you are working with a spring-
loaded valve.
Installing Pressure/Vacuum Relief Valves
with Only Spring-Loaded Pallets
1. Attach the valve to the appropriate mating ange
using a proper gasket. To ensure proper function,
install the valves to a level horizontal surface
so the pallet will move vertically. For Enardo
Models 860, 960 and 962, the valve shipped from
factory has certain studs installed.
Figure 6. Pressure and Vacuum Flow
PRESSURE FLOW VACUUM FLOW
Pressure Flow
Vacuum Flow
Pressure Flow
Vacuum Flow
5
Enardo 860 and 960 Series
Outside North America Only

3. Separate the protective cardboard coverings from
the pallets. Be careful not to damage the pallet
seal surface.
4. Reinsert uncovered valve pallets back into the
unit. Make sure the lower stem on the pallet is
centered into the valve seat. If the pallet appears
to be o󰀨 center to the valve chamber, or if there
is di󰀩culty positioning the lid or guide, carefully
inspect the pallet to ensure it is inserted properly.
Installing Pressure/Vacuum Relief Valves
with Weight-loaded Pallets
Note
The following steps 1 to 7 apply only to
valves that have a weight-loaded vacuum
or pressure pallet. These steps do not
apply to pallets that are spring-loaded on
both the pressure and vacuum sides.
1. If the valve has a weight-loaded vacuum, loosen
fasteners on top of the valve and remove the lid,
hood or guide.
2. Remove valve pallets from the unit.
6
Enardo 860 and 960 Series
Outside North America Only

5. To adjust valve settings higher than minimum,
use the weights included with the shipment to
increase the pressure setting. Weights are packed
separately within the unit shipping package and are
labeled “PRESSURE” and/or “VACUUM”. If weights
are shipped with the unit, they should be installed
onto the pallets in the valve chamber in which they
are labeled. Gently slide the weights onto the pallet
stem and down on top of the valve pallet.
6. Replace any lid, hood or guide that was previously
removed, and fasten securely. When tightening
down lids, make sure the O-ring in the lid has full
contact with the sealing surface.
7. Attach the valve to the appropriate mating ange
using proper gasket. To ensure proper function,
install the valve to a level horizontal surface so the
pallet will move vertically. Units that are tilted during
usage may su󰀨er premature damage or wear.
For more details on using weights to adjust the pallet
setting, refer to the Weight Information section.
Note
Before using your new Fisher™ pressure/
vacuum relief valve, make sure that your
valve is properly set for the appropriate
pressure and vacuum settings. Early or
delayed relief could be dangerous and/or
expensive depending on the application.
Spring–loaded valves are set at the
factory. Additional adjustment should not
be required and is not recommended.
7
Enardo 860 and 960 Series
Outside North America Only

Figure 7. Enardo 860 and 960 Series Common Valve Configurations
PIPE-AWAY SPRING-LOADED PRESSURE/VACUUM RELIEF VALVE
VENT-TO-ATMOSPHERE SPRING-LOADED PRESSURE/VACUUM RELIEF VALVE
ENARDO MODEL 860
SPRING LOADED PRESSURE/
SPRING LOADED VACUUM
SPRING LOADED PRESSURE/
SPRING LOADED VACUUM
SPRING LOADED PRESSURE/
SPRING LOADED VACUUM
SPRING LOADED VACUUM
SPRING LOADED VACUUM
SPRING LOADED VACUUM
SPRING LOADED VACUUM
SPRING LOADED VACUUM
ADAPTER
COVER
SPRING LOADED VACUUM
WEIGHT LOADED PRESSURE/
SPRING LOADED VACUUM
WEIGHT LOADED PRESSURE/
SPRING LOADED VACUUM
ENARDO MODEL 861
ENARDO MODEL 860
ENARDO MODEL 963
ENARDO MODEL 960
ENARDO MODEL 961
ENARDO MODEL 960
ENARDO MODEL 962
8
Enardo 860 and 960 Series
Outside North America Only

Maintenance
▲ WARNING
Ensure the tank is at atmospheric pressure
before opening or removing a valve.
Pressure build-up inside the tank can
cause a spray to be emitted from the valve
if opened under pressure.
Springs are energy storage devices and
are dangerous if handled improperly.
Never loosen any nuts or screws until
all spring preload has been relieved.
Instructions for removing spring preload
are provided in this section. Always use
appropriate safety equipment including
safety glasses or shields any time you are
working with a spring-loaded valve.
Determine if the pressure/vacuum relief valve
assembly is an Enardo 860 Series pipe-away
in-line conguration or an Enardo 960 Series vent-to
atmosphere conguration.
Enardo 860 Series Pipe-Away
See Figure 8 for reference.
1. Remove the cylindrical cap(s) from the lid(s) by
removing the small screws.
2. Turn the spring plunger clockwise to remove all
spring preload. Note the number of turns the
plunger has been turned to facilitate reassembly.
3. Remove the hex bolts holding the lid to the body
and lift o󰀨 the lid.
△ CAUTION
If the lid shows signs of any remaining
spring preload, do not continue with
the disassembly until this condition is
corrected. If the cap screws seem to be
under a load or if the lid starts to rise as
the cap screws are loosened, the spring
is still under load.
Figure 8. Enardo 960 Series Pressure/Vaccum Relief Valves
2 AND 3 IN. RELIEF VALVES
HEX NUTS
TYPICAL
4 PLACES
SCREWS
TYPICAL
4 PLACES
4 AND 6 IN. RELIEF VALVES
SCREWS
TYPICAL
3 PLACES
ENLARGED HOLES
WITH HEX NUTS
TYPICAL 3 PLACES
WING NUTS
TYPICAL
3 PLACES
9
Enardo 860 and 960 Series
Outside North America Only

4. The valve contains a single spring or a multiple
nested spring arrangement. Inspect the springs and
other internal parts for signs of deterioration and/or
corrosion. Replace any worn or damaged parts.
5. Remove any valve pallets and weights from the
unit if so equipped. Keep in mind that these will be
reinstalled, so keep track of the chamber from which
they were removed.
6. Inspect the pallets for any damage and/or buildup
that may a󰀨ect its sealing characteristics or its ability
to move properly inside the valve. If necessary, gently
clean the pallet and seal with a suitable solvent and
nonabrasive cloth.
7. Clean the removed parts with a suitable solvent.
8. Inspect the valve seats installed in the unit. The
sealing surfaces should be smooth and free of nicks
or buildup. Check the guides for anything that may
keep the valve pallet from moving properly inside
the valve. If necessary, gently clean the seats with a
suitable solvent and nonabrasive cloth.
9. If lid is available on the valve, clean any buildup that
may exist in or around the guide hole located in the
center of the part.
10. If the valve is tted with a screen of some type,
clear away any blockage that may impede
proper ow.
11. Reassemble the valve in reverse order
from disassembly.
12. Make sure the lower stem on the pallet is centered
into the valve seat. If the pallet appears to be o󰀨
center to the valve chamber, or if there is di󰀩culty
positioning the lid or guide, the pallet may be
inserted improperly.
13. Adjust the spring preload by returning the spring
plunger to its factory set location as noted earlier
or install on a pressure test stand and adjust to the
desired setting.
Enardo 960 Series Vent to Atmosphere
See Figures 8 and 9 for reference.
1. For 4 and 6 in. valves, remove the cylindrical cap(s)
from the lid(s) by removing the small screws.
2. Remove the hood by removing the wing nuts or
screws holding it in place. Hood can be removed
without releasing spring preload, but do not
remove the hex nuts until the spring preload has
been removed.
3. Follow steps 2 to 13 from the Enardo 860 Series
Pipe-Away Maintenance section on page 7.
Figure 9. Weights on Pallet
10
Enardo 860 and 960 Series
Outside North America Only

Weight Information
Note
Spring-loaded valves can have a weight-
loaded component.
The Fisher™ pressure/vacuum relief valve can achieve
various pressure and vacuum settings in units of
ounces per square inch (oz./sq. in.) or inches of water
column (in. w.c.) when weights are used. Standard Fisher
weight-loaded valve pallets installed without weights or
springs reach minimum settings of
1/2 oz./sq. in. or 1 in. w.c. The pallets’ setting is stamped
into the seal support located on the bottom side of the
pallet. The pallet’s setting of 1/2 oz./sq. in. or 1 in. w.c. is
etched into the support.
When a valve requires a setting higher than the
1/2 oz./sq. in. or 1 in. w.c. basic pallet setting, use weights
to increase the pallet’s set pressure. Fisher weights also
come in units of ounces per square inch (oz./sq. in.) or
inches of water column (in. w.c.). The individual setting
of each weight is either etched or imprinted into the
weight. Emerson o󰀨ers several di󰀨erent sizes of pressure/
vacuum relief valves. To ensure that the right weight is
placed on the right pallet, keep in mind that the weights
and pallets that go together will have the same outside
diameter. Standard Fisher weights allow the user to stack
in increments of 1/2 oz./sq. in. or 1/2 in. w.c.
Your Fisher pressure/vacuum relief valve shipment
includes prepackaged weight kits used to achieve the
proper settings for the valve you ordered. The package
labeled “PRESSURE” goes on the pallet in the pressure
chamber. The package labeled “VACUUM” goes on
the pallet in the vacuum chamber. All of the weights in
these packages should be installed. If one or neither of
these packages is included with your order, then they are
not needed.
If the pressure and vacuum weights are mixed together,
sort and reorganize the weights.
When installing weights for the Fisher pressure/vacuum
relief valve, check the required settings for the valve
located on the tag attached to the unit. Then add weights
to the pallet to achieve the required setting. For example,
if the relief valve’s setting is 6 oz./sq. in., add weights with
the total setting of 5-1/2 oz./sq. in. to the valve; the pallet
alone achieves 1/2 oz. setting. Therefore, the weights to
be added must total the remaining balance of the required
setting, which in this example is 5-1/2 oz. Hence, the
valve pressure setting is the sum of the settings of the
pallet and the weights.
Valve Repair
On occasion, valve housings or internal components
can be damaged due to accidents, improper usage
or wear. With Fisher’s modular design and unique
replaceable seat, many repairs to damaged valves
can be made on site instead on a remote repair site.
This feature causes minimal downtime if there is an
equipment breakdown or malfunction.
A damaged valve may require replacement of the
entire pressure or vacuum assembly, or it may require
a single component, such as a valve seat or pallet.
All Fisher seats and pallets are tested for their sealing
capabilities before they are shipped from the plant.
Fisher assemblies and components can be quickly and
easily installed. Once installed, the valve is ready for
continued dependable operation.
Contact your local Sales O󰀩ce with any questions
or additional assistance you may need for repairing
your valve.
11
Enardo 860 and 960 Series
Outside North America Only

Enardo 860 and 960 Series
Facebook.com/EmersonAutomationSolutions
LinkedIn.com/company/emerson-automation-solutions
Twitter.com/emr_automation
[email protected]
Outside North America Only
D103814X012 © 2015, 2022 Emerson Process Management Regulator
Technologies, Inc. All rights reserved. 02/22.
The Emerson logo is a trademark and service mark of Emerson Electric
Co. All other marks are the property of their prospective owners.
Fisher™ is a mark owned by Fisher Controls International LLC, a
business of Emerson Automation Solutions.
The contents of this publication are presented for informational purposes
only, and while every e󰀨ort 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
specications of such products at any time without notice.
Emerson Process Management Regulator Technologies Tulsa, LLC
does not assume responsibility for the selection, use or maintenance of
any product. Responsibility for proper selection, use and maintenance of
any Emerson Process Management Regulator Technologies Tulsa, LLC
product remains solely with the purchaser.
Emerson Automation Solutions
Americas
McKinney, Texas 75070 USA
T [phone]
[phone]
Tulsa, OK 74146 USA
T [phone]
Europe
Bologna 40013, Italy
T [phone]
Asia Pacic
Singapore 128461, Singapore
T [phone]
Middle East and Africa
Dubai, United Arab Emirates
T [phone]
Enardo.com