The Y695VR Series direct-operated vacuum regulators are used where a decrease in vacuum must be limited,
such as between a tank and vacuum source to control vacuum in tank. The Type Y695VR has internal pressure
registration. The Type Y695VRM has a control line connection and blocked throat for external pressure registration.
Features
• Tamper Resistant Adjustment—Closing cap
and spring case on many types allow installation
of sealing wire to discourage or detect
unauthorized adjustment of pressure setting.
• Precision Control of Low Pressure Settings—
Large diaphragm areas provide more accurate
control at low pressure settings.
• Easy Conversion—The Y695VR Series Vacuum
Regulators are easily adapted between external
and internal registration.
• Common Spare Parts—The Type Y695VR and
Type Y695VRM share common spare parts with
the other Y690A Series products.
• Corrosion Resistance—Constructions are
available in a variety of materials for compatibility
with corrosive process gases.
www.emersonprocess.com/regulators
D102597X012
Bulletin 71.3:Y695VR
Specications
Available Congurations
Type Y695VR: Direct-operated vacuum regulator
Type Y695VRM: Direct-operated vacuum regulator
with blocked throat for external pressure registration
Body Sizes and End Connection Styles
BODY SIZE,
INCHES (DN)
3/4 or 1 (20 or 25)NPT
1. Weld-on ange dimension is 14-inches (356 mm) face-to-face.
Maximum (Casing) Pressure
END CONNECTION STYLES
Ductile IronSteel or Stainless Steel
(2)
(1)
NPT, SWE,
or CL150 RF
Full Vacuum
Maximum Downstream Pressure
(2)
Full Vacuum
Change in Control Pressure to Wide-open
(2)
See Table 2
Pressure RegistrationType Y695VR: Internal Type Y695VRM: External
Orice Size7/16-inch (11 mm)
CapacitiesSee Table 2
1. End connections for other than U.S. standards can usually be provided; consult the local Sales Ofce.
2. The pressure/temperature limits in this bulletin and any applicable standard or code limitation should not be exceeded.
Flow Coefcients
Cg: 120
Cv: 3.43
C1: 35
Material Temperature Capabilities
Nitrile (NBR): -20° to 180°F (-29° to 82°C)
Fluorocarbon (FKM):40° to 300°F (4° to 149°C)
Peruoroelastomer (FFKM):
-20° to 300°F (-29° to 149°C)
Spring Case Connection1/4-inch NPT
Diaphragm Case Connection1/2-inch NPT
Construction MaterialsSee Table 1
Pressure Setting AdjustmentAdjusting nut
Additional OptionsUmbrella vent assembly for spring
case connection
The Y695VR Series vacuum regulators are used
to maintain a constant vacuum at the regulator
inlet. A decrease in this vacuum (increase in
absolute pressure) beyond this value registers on
the diaphragm and opens the disk. This permits a
downstream vacuum of lower absolute pressure than
the upstream vacuum to restore the upstream vacuum
to its original pressure setting. On the Type Y695VR,
pressure registers underneath the diaphragm. The
Type Y695VRM has a control line connecting the
diaphragm casing to the vacuum line and an O-ring
stem seal blocking the throat causing pressure to
register through the control line.
Capacity Information
To determine the ow capacities for the Y695VR Series
vacuum regulators, use the following formula:
Bulletin 71.3:Y695VR
Q = P
1abs Cg
SIN
3415
C
∆P
Deg.
P
1
1abs
where,
Q = ow capacity in SCFH (60°F and 14.7 psia) of
air at 60°F
P
= absolute inlet pressure in psia (P1 gauge + 14.7)
If the actual change in (control) pressure
(from the service conditions) is less
than the minimum change in (control)
pressure required to fully open the
vacuum regulator (Table 2), the Cg in the
formula must be reduced accordingly.
To obtain the correct reduced Cg,
multiply the Cg from specications
table by the ratio of the actual change
in (control) pressure to the minimum
change in (control) pressure required to
fully open the vacuum regulator.
Conversion Factors
To determine equivalent capacities of natural gas,
propane, butane, or nitrogen, multiply the calculated
capacity by the following appropriate conversion
factor: 1.29 for natural gas, 0.810 for propane,
0.707 for butane, or 1.018 for nitrogen. For gases of
Figure 2. Type Y695VR Operational Schematic
other specic gravities, divide by the square root of
the appropriate specic gravity. Then, if capacity is
desired in normal cubic meters per hour at 0°C and
1.01325 down to allow condensate to drain. On indoor
installations, this connection should be piped outdoors
if used in hazardous gas service. External dimensions
and connections are shown in Figure 3.
Note
Downstream piping will vary with the
installation, but to obtain the calculated
characteristics, the pipe should be the
same size as the outlet and should be
straight for the rst 18-inches (457 mm).
Ordering Information
When ordering, specify:
Application
1. Composition and specic gravity of gas (including
chemical analysis if possible)
2. Range of temperatures, owing inlet pressures
(maximum, minimum, nominal), and pressure drops
3. Desired pressure setting or range
4. Range of ow rates (minimum controlled,
maximum, normal)
whenever there is a choice to be made. Always be
sure to specify the type number and the spring case
connection location from Figure 3.
TESCOM
Emerson Process Management
Regulator Technologies, Inc.
USA - Headquarters
McKinney, Texas 75069-1872 USA
Tel: 1-800-558-5853
Outside U.S. 1-972-548-3574
Asia-Pacic
Shanghai, China 201206
Tel: +86 21 2892 9000
Europe
Bologna, Italy 40013
Tel: +39 051 4190611
Middle East and Africa
Dubai, United Arab Emirates
Emerson Process Management
Regulator Technologies, Inc.
USA - Headquarters
McKinney, Texas 75069-1872 USA
Tel: 1-800-558-5853
Outside U.S. 1-972-548-3574
Asia-Pacic
Singapore, Singapore 128461
Tel: +65 6777 8211
Europe
Bologna, Italy 40013
Tel: +39 051 4190611
Gallardon, France 28320
Tel: +33 (0)2 37 33 47 00
Emerson Process Management
Tescom Corporation
USA - Headquarters
Elk River, Minnesota 55330-2445 USA
Tel: 1-763-241-3238
Europe
Selmsdorf, Germany 23923
Tel: +49 (0) 38823 31 0
Tel: +971 4811 8100
For further information visit www.emersonprocess.com/regulators
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