Emerson ENARDO 860 Series User manual

860 and 960 Series
February 2022
North America Only
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.
Enardo 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.
Introduction
Scope of the Manual
This Instruction Manual provides instructions
for installation, maintenance and parts ordering
information for the 860 and 960 Series spring-loaded
pressure/vacuum relief valve (SL-PVRV).
Figure 1. Model 860 Spring-Loaded Pressure/
Vacuum Relief Valve
Figure 2. Model 960 Spring-Loaded Pressure/
Vacuum Relief Valve
Instruction Manual
D103813X012

860 - X - - /
- -
/ -
960 - - - /
2
860 and 960 Series
North America Only
Specications
The Specications section on this page provides specications for the 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.
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
Pallet and Seat
Material
1 = PPS Polyphenylene
Sulde (max 5 psi)
2 = 316 Stainless Steel
(max 14.99 psi)
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)
Pressure 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
Vacuum Units
z = oz./sq.in.
n = in. w.c.
mm = mm w.c.
mb = mbar
p = psi.
Vacuum Setting
Maximum = 14.99 psig /
1034 mbarg
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
Inlet
Connection
Size
(2 through
6 in.)
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 psig)
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)
Pressure 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
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
Vacuum Units
z = oz./sq.in.
n = in. w.c.
mm = mm w.c.
mb = mbar
p = psi.
Vacuum Setting
Maximum = 14.99 psig /
1034 mbarg
MODEL 860 SPRING-LOADED PRESSURE/VACUUM RELIEF VALVE MODEL NUMBER
MODEL 960 SPRING-LOADED PRESSURE/VACUUM RELIEF VALVE MODEL NUMBER
Figure 3. Pressure/Vacuum Relief Valve Model Number
Teon®and Viton®are marks owned by E. I. du Pont de Nemours and Company.

3
860 and 960 Series
North America Only
Product Description
The 860 and 960 Series spring-loaded pressure/
vacuum relief valves are designed to handle higher
pressure settings than standard dead weight-
loaded valves.The 860 Series is used for pipe-away
aplications while 960 Series is used for vent-to-
atmosphere applications. Enardo 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 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.
• Model 860: Pressure/Vacuum Relief Valve -
Pipe-Away
• Model 861: Top Mount Pressure or Side Mount
Vacuum Relief Valve - Pipe-Away
• Model 960: Pressure/Vacuum Relief Valve -
Vent-to-Atmosphere
• Model 961: Pressure Relief Valve -
Vent-to-Atmosphere
• Model 962: Top Mount Vacuum Relief Valve -
End of Line
• Model 963: Side Mount Vacuum Relief Valve
MODEL 860 MODEL 861 MODEL 960
MODEL 961 MODEL 962 MODEL 963
Figure 4. 860 and 960 Series Spring-Loaded Pressure/Vacuum Relief Valve Available Models

II 1 G Ex h IIC T6 Ga
II 2 G Ex h IIC T6 Gb
4
860 and 960 Series
North America Only
Principle of Operation
The Enardo spring-loaded pressure/vacuum reliefThe Enardo spring-loaded pressure/vacuum relief
valve maintains a tight seal, until system pressure orvalve maintains a tight seal, until system pressure or
vacuum exceeds the set pressure of the valve. Setvacuum exceeds the set pressure of the valve. Set
pressure is established by the force of a spring or a setpressure is established by the force of a spring or a set
of multiple springs acting on the valve pallet. When theof multiple springs acting on the valve pallet. When the
system pressure is above the set pressure, the palletsystem pressure is above the set pressure, the pallet
starts to lift, breaking the seal between the seat andstarts to lift, breaking the seal between the seat and
pallet. This allows vapors to pass through the valvepallet. This allows vapors to pass through the valve
orice and relieve pressure buildup. The valve reseals orice and relieve pressure buildup. The valve reseals
upon relief and remains sealed.upon relief 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 Enardo Valve Sizing Program
displays the utter zone. Contact your local Sales
O󰀩ce with any questions or additional assistance.
Product Identication and Marking
Hazardous Locations
Enardo 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
OUTER HOUSING OF STAINLESS STEEL,
CARBON STEEL OR COATED ALUMINUM
OUTER HOUSING OF UNCOATED ALUMINUM
Figure 5. ATEX Certified Markings

Pressure Flow
Vacuum Flow
Pressure Flow
Vacuum Flow
5
860 and 960 Series
North America Only
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 Models 860,
960 and 962, the valve shipped from factory has
certain studs installed.
2. Orient valve in desired direction. 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.
PRESSURE FLOW VACUUM FLOW
Figure 6. Pressure and Vacuum Flow

6
860 and 960 Series
North America Only
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.
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.

7
860 and 960 Series
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 Enardo 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.

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

9
860 and 960 Series
North America Only
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.
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 860 Series pipe-away in-
line conguration or a 960 Series vent-to
atmosphere conguration.
SCREWS
TYPICAL
4 PLACES
HEX NUTS
TYPICAL
4 PLACES SCREWS
TYPICAL
3 PLACES
ENLARGED HOLES
WITH HEX NUTS
TYPICAL 3 PLACES
WING NUTS
TYPICAL
3 PLACES
2 AND 3 IN. RELIEF VALVES 4 AND 6 IN. RELIEF VALVES
Figure 8. 960 Series Pressure/Vaccum Relief Valves

10
860 and 960 Series
North America Only
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 860 Series Pipe-
Away Maintenance section on page 7.
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.
Figure 9. Weights on Pallet