Groth 3000 User Manual
Installation, Operation and Maintenance Manual for
Blanket Gas Regulator
Series 3000
ISO 9001
Groth Corporation 1993
IOM 3000.0
JULY 1993
IOM 3000.0
REV. A 12541
TABLE OF CONTENTS
SECTION DESCRIPTION PAGE NO.
A MAIN SECTION
INTRODUCTION
GENERAL
INFORMATION
SAFETY
INSTALLATION
OPERATION &
MAINTENANCE
DRAWINGS & BILL
OF MATERIAL
B LIST OF FIGURES*
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
C LIST OF TABLES
No.
1
2
3
4
5
6
7
8
9
Regulator Design, Function & Operation
Regulator Function - Flowing/Shut-off Condition
General Instructions
Inspection & Installation
Operation: Pressure Setting
Operation: Flow Capacity Setting
Blanketing the Tank
Recommended Spare Parts
Troubleshooting Guide
Preventive Maintenance & Disassembly
Assembly
Recommended Testing & Setting Procedure
Exploded View - Drawing
Bill of Material
Cross-Sectional - Drawing
Model Identification & Product Limited Warranty
DESCRIPTION
Tank Installation - Safety Equipment
Regulator Function - Flowing Condition
Regulator Function - Shut-off Condition
Blanketing Regulator Installation
Orifice Sleeve Orientation
Spring Bonnet Assembly
Piston/Body Assembly
Piston Assembly - "Exploded"
Orifice Sleeve Orientation
Orifice Sleeve Orientation
Piston Assembly - "Exploded"
Piston/Body/ Diaphragm Assembly
Spring Bonnet Assembly
Blanketing Regulator - "Exploded" Assembly
Blanketing Regulator - Cross-Sectional Assembly
DESCRIPTION
3000 Series Regulator Specifications
Flow Capacity
Model 3000 Spring Table
Model 3010 Spring Table
Model 3020 Spring Table
Orifice Selection
Recommended Spare Parts
Recommended Bolt Torque
Bill of Material - 3000 Series Regulator
1
2
3
4
5
6
7
8
8
9
10 - 11
12 - 13
14
15
16
17
18
1
3
3
5
7
10
10
11
11
12
12
13
13
15
17
2
2
6
6
6
7
8
13
16
IOM 3000.0
REV. A 12541
*Note: Some Figures are duplicated for the convenience of the reader
P
INTRODUCTION
The gas blanketing regulator is one of the principal
components typically installed on a storage tank to
protect the tank and its contents. It is a precision
regulator that is capable of maintaining a very low
gas pressure (1/2" WC minimum) in the tank by
controlling the flow of a high pressure (200 PSI
maximum) blanketing gas. It maintains a positive
tank pressure when fluid is pumped out or as fluid
temperature decreases.
Typically nitrogen or another compatible gas is used
to displace the tank product vapors. This reduces
product evaporation and prevents atmospheric
contaminants, including moisture, from entering the
tank, minimizing internal tank corrosion and product
contamination. The use of inert blanketing gas
minimizes air pollution due to leakage or emergency
venting.
Figure 1: Tank Installation - Safety Equipment
In addition to the blanketing regulator, a tank must be
protected from structural damage by pressure and
vacuum relief valves. A typical tank installation is
shown in Figure 1 which includes the regulator, a
pressure vacuum relief valve and an emergency
pressure relief valve. Groth Corporation
manufacturers all of these devices.
The regulator must be carefully maintained by a
knowledgeable valve technician. It should only be
assembled under clean conditions, preferably in a
shop environment. Carefully read and understand
this manual before attempting to adjust set pressure
or flow capacity, or repair the regulator. Groth
Corporation offers repair services for all products
manufactured by the Tank Protection Division.
RESSURE/VACUUM
RELIEF VALVE
GROTH MODEL 1420
GAS BLANKET REGULATOR
GROTH MODEL 3000
BLANKET
GAS
EMERGENCY RELIEF VALVE
GROTH MODEL 2400
GAUGE
SENSE LINE
SUPPLY
IOM 3000.0
REV. A 12541
REGULATOR DESIGN, FUNCTION &
OPERATION
The Groth Model 3000 Regulator is a high capacity
spring operated, diaphragm type, balanced piston
regulator design for tank blanketing applications.
The regulator controls the flow of blanketing gas to
the vapor space in the storage tank. When the
internal pressure of the tank is at or above set
pressure, the diaphragm force exceeds the spring
force and the regulator is shut off bubble tight.
When the tank pressure falls below the set point, the
spring force opens the regulator and blanket gas
flows into the tank (See Figures 2 and 3).
The regulator must be sized to provide sufficient
blanket gas to prevent the loss of tank pressure due to
liquid discharge or decreased ambient temperature.
Table 2 lists the maximum flow capacity of the
regulator for various blanketing gases. Actual
system flow will depend on supply system piping,
tank connection piping and position of the internal
orifice sleeve. Set pressure is the pressure at which
the regulator begins flowing when tank pressure is
decreasing and stops flowing when tank pressure is
increasing.
This manual is intended to provide recommended
procedures and practices for installation, operation,
and maintenance of the Groth Series 3000 Regulator.
Any standard procedures and practices developed in
a specific plant or process should supersede this
manual. Although this manual cannot cover all
possible contingencies, following these guidelines
should provide safe regulator performance.
For information not contained in this manual, please
contact:
Groth Corporation
Groth Products Group
P. O. Box 15293
Houston, TX. 77220
713-675-6151 (phone)
713-675-6739 (fax)
Note that throughout this manual, the item numbering
is listed in [ ] after the part description. Refer to the
exploded assembly drawing on page 15 and the parts
list on page 16.
TABLE 1
REGULATOR SPECIFICATIONS
3000 3010 3020
Flow
Coefficient
(CV)
Inlet/Outlet 1" NPT (F)
Supply Pressure 200 PSI
Tank Pressure 2" WC to
Max. Tank
MAWP
12.5 12.5 12.5
or
1"150# RF
Flange
2.0 PSI
25 PSI 10 " WC 150 PSI
1" NPT (F)
or
1" 150# RF
Flange
200 PSI
1/2" WC to
2" WC
1" NPT (F)
or
1" 150# RF
Flange
200 PSI
1 PSI to
10 PSI
TABLE 2
FLOW CAPACITY *
3000 SERIES REGULATOR SCFH
Supply
Pressure
PSI
5
10
15
20
30
40
50
60
80
100
120
140
160
180
200
Nitrogen Natural
Gas
0.6 G
5700
8700
11300
13800
18600
23200
27700
32100
40700
49300
57900
66500
75100
83700
92300
5800
8800
11500
14000
18900
23600
28200
32600
41300
50100
58800
67500
76300
85000
93700
Air
7400
11300
14600
17900
24000
30000
35800
41500
52600
63700
74800
85900
97000
108100
119200
Internal orifice sleeve installed in 100% flow capacity
*
position.
1
P
R
Figure 2: Regulator Function - Flowing Condition
VENT
INLET
HIGH PRESSURE
OUTLET
HIGH PRESSURE
BLANKETING GAS
BLANKETING GAS
VENT
SENSE PORT
LOW PRESSURE
PROCESS VAPOR
Figure 3: Regulator Function - Shut-off Condition
INLET
HIGH PRESSURE
OUTLET
LOW PRESSURE
PROCESS VAPOR
SENSE PORT
LOW PRESSURE
ROCESS VAPO
BLANKETING GAS
VENT
2
SAFETY
GENERAL INSTRUCTIONS
This section is intended as an overview of safety
guidelines that should be followed during the
installation, operation and maintenance of Groth
Series 3000 Gas Blanketing Regulator. To
understand the context of these warnings and
instructions, read and understand this complete
manual.
The gas blanketing regulator is one of the principal
protection devices typically installed on a product
storage tank. It is a precision regulator that is
designed to maintain a positive pressure on the tank.
This will prevent product loss or contamination from
atmospheric air when pumping liquid out or when the
stored fluid cools.
WARNING
1. In the event of an actuator or body diaphragm
failure, the regulator will fail in the OPEN
position. Gas flow will NOT be shut off.
Operating and emergency pressure relief valves
must be sized to flow regulator capacity in
addition to normal and emergency venting
requirements.
2. Gas Blanket Regulator flow capacity is based on
tests conducted with five feet of 1" SCH. 40
discharge piping. Consult factory for capacity
data if regulator is to be installed with longer
pipe or numerous fittings or va lves between the
regulator and the tank it is blanketing.
3. The regulator is normally factory set at the
desired set pressure and orifice restriction.
These settings and spring range are stamped on
the nameplate. DO NOT attempt to readjust the
set pressure beyond the limits specified in Tables
3, 4 and 5.
4. The regulator is to be connected to the tank or
vessel with a minimum 0.300" ID tubing sense
line. This line must be kept open and
unobstructed to ensure that the regulator
"senses" the actual tank pressure. For some
applications, a nitrogen purge may be required
to ensure that this line remains open. Consult
factory for recommendations.
5. DO NOT attempt to remove the regulator from
the line or perform field repairs in line without
first isolating the regulator from both the tank
and the supply gas line. Bleed all pressure
before removing the spring bonnet or the flow
orifice locking screw, or opening up the actuator
cases.
6. Note the orifice sleeve position when
disassembling the regulator. It was factory set
according to the flow requirements listed on the
order and must be re-installed in the same
position to ensure the correct flow.
7. The regulator body and actuator case are
exposed to process vapors. Observe all safety
precaution as specified on the Material Safety
Data Sheet for the products that are in the tank.
8. The vents on the spring bonnet and upper case
must both be clean and open to the atmosphere
and should be inspected periodically.
3
INSPECTION AND INSTALLATION
B
The regulator is packaged and supported to prevent
damage or contamination in shipping. It should be
similarly protected during subsequent handling and
storage. Always keep all ports plugged to prevent
intrusion of foreign materials. Before installation,
inspect the unit visually. If there are indications of
physical damage or internal contamination, the
regulator must be disassembled, cleaned and
inspected before installation. If factory set, the
spring adjustment cap and the orifice selector locking
screw must be secure. Report any shipping damage
to your carrier.
The regulator inlet and outlet connections are 1" NPT
(F) or 1" 150# RF ANSI flange. The regulator must
be installed level, the direction of the flow is marked
on the body. It is to be installed in accordance with
accepted piping practices. Full bore block valves
should be installed upstream and downstream of the
regulator and in the sense line to allow it to be
removed from the system for maintenance.
Figure 4: Blanketing Regulator Installation
The regulator discharge line must be as short as
possible to obtain the rated gas flow rate. It is not
recommended to exceed a 5' length of 1" SCH 40
pipe. Consult with the factory for piping
recommendations if it is necessary to install the
regulator a greater distance from the tank. The
supply line must be capable of providing the rated
flow at the minimum supply pressure. The sense line
should be minimum 300" ID tubing and is to be
connected to the tank at least 12" from the regulator
discharge line (See. Figure 4).
WARNING
Regulator flow capacity listed in Table 2 is based on
tests with 5' of 1" SCH. 40 discharge pipe and a 2"
supply hose reduced to 1" pipe at regulator supply
port. Depending on discharge line size, length and
number of fittings, regulator flow capacity may be
less than published curves. Supply and discharge
piping should be designed to minimize losses at
desired flow condition. Consult factory for nonstandard installation regarding flow capacity.
BLANKET
GAS
SUPPLY
BLOCK VALVE-1/2" MIN FULL BORE
TANK ROOF
(3)
SENSE LINE
(1)
12" MIN
(2)
LOCK VALVE-1" MIN FULL BORE
DISCHARGE
PIPING
5' MAX
LENGTH
TANK
PRESSURE
GAUGE
4
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