• Precision Control—Large diaphragm area
provides very accurate throttling control at low
pressure settings.
• Easy Conversion—Changes easily from the
Type Y695A to the Type Y695AM with two O-rings
and a machine screw.
• Rugged Construction—Heavy duty casings and
internal parts are designed to reduce vibration and
shock and give this regulator the ability to
withstand 150 psig (10,3 bar) inlet pressure with
no internal parts damage.
• Simplicity—Direct-operated, straightforward stem
and lever design minimizes the number of parts
while providing excellent regulation of pressure.
Introduction
The Y695A Series are direct-operated vapor recovery
regulators. These regulators are used to sense an
increase in vessel pressure and vent excessive internal
tank pressure to an appropriate vapor recovery disposal
or reclamation system. They may also be used as
backpressure regulators or relief valves.
www.sherregulators.com
D102595X012
Page 2
Bulletin 74.2:Y695A
Specications
Available Congurations
Type Y695A: Direct-operated vapor
recovery regulator.
Type Y695AM: Direct-operated vapor recovery
regulator equipped with a blocked throat and O-ring
stem seal. The lower diaphragm casing is tapped
1/2 NPT for control line connection.
Body Sizes
NPS 3/4 or 1 (DN 20 or 25)
End Connection Styles
See Table 1
Maximum Allowable Inlet (Casing) Pressure
(1)
150 psig (10,3 bar)
Maximum Outlet Pressure
(1)
150 psig (10,3 bar)
Maximum Emergency Inlet Pressure to Avoid
Internal Parts Damage
150 psig (10,3 bar)
Control Pressure Ranges
(1)
See Table 2
Flow Coefcients with Fully Open Disk
Cg: 120, CV: 3.43, C1: 35
Flow Capacities
See Table 4
Orice Size
7/16-inch (11 mm)
Construction Materials
See Table 3
Material Temperature Capabilities
Nitrile:
-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)
Ethylenepropylene (EPDM):
-20° to 300°F (-29° to 149°C)
Pressure Setting Adjustment
Adjusting Screw
Spring Case Vent Connection
1/4 NPT
Diaphragm Case Connection
1/2 NPT
Approximate Weight
19 pounds (9 kg)
(1)
1. The pressure/temperature limits in this bulletin and any applicable standard or code limitation should not be exceeded.
Table 1. End Connection Styles
BODY SIZES,
NPS (DN)
3/4 or 1 (20 or 25)NPT
1. All anges have 14-inches (356 mm) face-to-face.
Ductile Iron
END CONNECTION STYLES
CF8M
Stainless Steel
NPT, ANSI Class 150 RF,
ANSI Class 300 RF, or PN 16/25/40
(1)
Table 2. Control Pressure Ranges
RELIEF SET PRESSURE RANGE
2 to 7-inches w.c.
3 to 13-inches w.c.
10 to 26-inches w.c.
0.9 to 2.5 psig
1.3 to 4.5 psig
3.8 to 7 psig
1. Spring ranges based on spring case installed pointed down. When installed pointing up, the spring ranges increase by 2-inches w.c. (5 mbar).
2. Do not use Fluorocarbon (FKM) diaphragm with these springs at diaphragm temperatures lower than 60°F (16°C).
(5 to 17 mbar)
(7 to 32 mbar)
(25 to 65 mbar)
(0,06 to 0,17 bar)
(0,09 to 0,31 bar)
(0,26 to 0,48 bar)
A+--Best possible selection
A--Recommended
B--Minor to moderate effect. Proceed with caution.
C--Unsatisfactory
I.L.--Information lacking
I.L.
C
C
A
A
A
C
C
A
A
A
A
A
A
A
A
C
C
A
A
C
C
C
C
B
B
B
B
A
A
C
C
A
A
A
A
C
C
A
A
A
A
A
C
A
A
A
A
A
A
C
C
C
C
C
C
B
B
B
C
A
A
B
B
C
C
C
C
Ductile Iron
Stainless Steel
CF8M or S31600
S30200 or S30400
C
C
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
B
A
A
A
A
B
A
A
A
A
B
A
A
A
A
B
A
A
A
B
B
A
A
A
A
A
A
A
A
A
A
A
A
C
C
C
C
B
B
B
A
A
A
A
A
B
B
C
C
A
A
®(1)
S41600
Monel
Stainless Steel
Stainless Steel
C
C
A
A
B
A
C
C
A
A
A
A
A
A
A
A
C
C
A
A
C
B
C
C
C
B
B
A
A
A
B
C
A
A
B
A
B
A
A
A
B
A
B
B
A
A
B
A
B
A
C
C
C
B
C
C
B
A
B
A
B
A
C
A
C
C
B
A
(2)
C
®
Hastelloy
B
A
B
A
A
A
A
A
B
A
A
I.L.
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
- continued -
Principle of Operation
Y695A Series vapor recovery regulators are used to
maintain a constant blanket (inlet) pressure or vessel
pressure with the outlet owing to a system whose
pressure is lower than the inlet (see Figure 2).
4
When vessel pressure increases above the setpoint
of the regulator due to pumping in or thermal heating,
the force of the control spring is overcome by pressure
acting on the diaphragm. This moves the disk away
from the orice, allowing gas to ow from the vessel
to the vapor recovery system. As vessel pressure is
Water (Ambient)
Water [at 200°F (93°C)]
Water (Sea)
A+--Best possible selection
A--Recommended
B--Minor to moderate effect. Proceed with caution.
C--Unsatisfactory
I.L.--Information lacking
Neoprene
(CR)
C
B
A
A+
A
B
C
A
B
A
B
C
C
C
C
C
A
B
A+
A+
A
B
A
A
B
C
A
A
B
C
A
B
A
B
A
B
C
A
C
FLUID INFORMATION
Nitrile
(NBR)
B
C
A
A
C
C
C
A
C
A+
A
C
C
C
B
C
A
A
A
C
A
A+
A
C
C
A
A+
B
C
C
A
A+
A
A
C
C
C
A
B
Material
Fluorocarbon
(FKM)
B
C
B
C
C
C
A
B
B
A
A
A
A
A
A+
C
A
A+
B
C
B
A
A
C
C
A
A
C
A
A
A
A
A
A
A
A
A
A
B
Bulletin 74.2:Y695A
Peruoroelastomer
(FFKM)
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
Ethylenepropylene
(EPDM)
A
A
A
A
A
B
C
A
C
C
C
C
C
C
C
B
A
C
B
A
A
C
A
A
A
I.L.
C
C
C
C
A
C
C
A
A
B
B
A
A
reduced, the force of the back disk spring causes the
disk to move toward the orice, decreasing the ow of
gas out of the vessel. As vessel pressure drops below
the setpoint of the regulator, the disk will seat against
the orice, shutting off the ow of gas.
Sizing Vapor Recovery Systems
To determine the capacity required, you must consider
the amount of blanketing gas that must be displaced
from the tank when either lling the vessel with liquid
(pump-in) or the expansion of tank vapors during
atmospheric thermal heating.
Using the established procedures from American
Petroleum Institute Standard 2000 (API 2000),
determine the required ow rate for outbreathing.
For liquids with a ash point below 100°F (38°C) or a
normal boiling point below 300°F (149°C), multiply the
calculated outbreathing requirements in Table 6 by 2.0
as indicated in footnote 1 from Table 6.
5
Page 6
Bulletin 74.2:Y695A
Table 6. Flow Rate Conversions (Gas ow required to displace
blanketing gas with pump-in of liquid.)
MULTIPLY MAXIMUM
PUMP RATE IN
U.S. GPM
U.S. GPH
Barrels/hour
Barrels/day
1. For liquids with a ash point below 100°F (38°C) or normal boiling point below 300°F
(149°C), multiply the above calculated outbreathing requirement by 2.0.
2. To convert to Nm³/h multiply SCFH by 0.0268.
BYTO OBTAIN
8.021
0.1337
5.615
0.2340
SCFH air
required
(1)(2)
1. Determine the ow rate of blanketing gas displaced
when liquid is being pumped in (see Table 6).
2. Determine the gas ow rate due to “outbreathing”
caused by atmospheric thermal heating (see
Table 7).
3. Add the requirements of steps 1 and 2 and select
a vapor recovery regulator size based on total
capacity required from Table 4.
Sample sizing problem for vapor
recovery applications:
given capacity of nitrogen by 0.985, and divide by the
square root of the appropriate specic gravity of the
gas required. To determine regulating capacities at
pressure settings not given or to determine wide-open
ow capacities, use the following formula:
2. From Table 7 the desired air ow rate = 1000 SCFH
(26,8 Nm3/h) air due to thermal heating.
3. Total required ow rate = 1000 SCFH (26,8 Nm3/h)
air + 320 SCFH (8,58 Nm3/h) = 1320 SCFH
(35,4 Nm3/h) air. This converts to nitrogen
requirements of 1340 SCFH (35,9 Nm3/h).
Capacity Information
Table 4 gives typical nitrogen regulating capacities at
selected inlet pressures and outlet pressure settings.
Flows are in SCFH at 60°F and 14.7 psia and Nm³/h at
0°C and 1,01325 bar of 0.97 specic gravity nitrogen.
For gases of other specic gravities, multiply the
6
520
Q = CgP1SIN
GT
3417
C
∆P
Deg.
P
1
1
Where:
Cg = gas sizing coefcient from Specications
C1 = Cg/CV or 35 from Specications
G = gas specic gravity (air = 1.0)
P
= inlet pressure, psia (add 14.7 psi to gauge inlet
1abs
pressure to obtain absolute inlet pressure)
Q = ow rate, SCFH
T = absolute temperature in °Rankine of gas at inlet
(°Rankine = °F + 460)
∆P = Pressure differential across the valve,
psig (P1 - P2)
Page 7
Installation
Bulletin 74.2:Y695A
Install the regulator using a straight run of pipe the
same size or larger as the regulator body. Flow
through the regulator body is indicated by the ow
arrow on the body. If a block valve is required, install a
B
14
(356)
B2441
INCHES
(mm)
A
5.56
(141)
full ow valve between the regulator and the blanketed
vessel. For proper operation at low setpoint ranges,
the regulators should be installed with the spring case
pointed down.
1. Type of gas being controlled (natural gas, air, etc.);
list any factors such as impurities in the gas that
may affect compatibility of gas with the regulator
trim parts.
2. Specic gravity of the gas.
3. Temperature of the gas.
4. Range of owing inlet pressures to regulator.
5. Flow rates
a) Minimum controlled ow
b) Normal ow
c) Maximum ow
6. Line size and end connection size of adjacent piping.
Regulator
Refer to the Specications table on page 2. Carefully
review the description of each specication and make
the desired selection wherever there is a choice.
Always specify the type number.
Industrial Regulators
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
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Tel: +86 21 2892 9000
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Bologna, Italy 40013
Tel: +39 051 4190611
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Dubai, United Arab Emirates
Tel: +971 4811 8100
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Natural Gas Technologies
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