Installation, Operation and Maintenance Manual for
1401E
PILOT VALVE
IOM 1401E.1
MAY 2006
Groth Corporation 2006
ISO 9001
IOM 1401E.1
REV. A 12541
TABLE OF CONTENTS
GENERAL INFORMATION
Pilot Valve Design and Function 2-3
SAFETY
General Instructions 3-4
INSTALLATION
Inspection and Installation 4
OPERATION AND MAINTENANCE
Modes of Operations
Equipment Options Operation
Troubleshooting Guide
Recommended Spare Parts
Maintenance
Disassembly
Assembly
Recommended Testing & Setting Procedure
Bill of Material
Model Identification
Product Limited Warranty
LIST OF FIGURES
1. Tank Installation - Safety Equipment
2. Pilot Valve Function-Shut off Condition
3. Operation - Closed Position
4. Operation - Open, Snap Action
5. Operation - Open Modulating
6. Operation - Reseat, Snap Action
7. Operation - Reseat Modulation
8. Options - Vent Piped to Discharge
Header
9. Options - Field Test Connection
10. Options - Manual/Remote Blowdown
11. Body Sub - Assembly
12. Stem Sub - Assembly
13. Test Apparatus
14. Exploded Assembly
15. Cross Sectional Assembly
LIST OF TABLES
1. Pilot Valve Specifications
2. Spring Table
3. Recommended Spare Parts
4. Recommended Bolt Torque
5. Setting Specifications - Pilot Valve
4-6
6-7
8
8
8
9
9-10
11
12
15
15
2
2
5
5
5
6
6
6
7
7
9
10
11
13
14
3
5
8
9
11
INTRODUCTION
Pressure and/or vacuum relief valves are used on
liquid storage tanks and other process vessels or
systems to prevent structural damage due to excess
internal pressure or vacuum.
Storage tanks are pressurized when liquid is pumped
in, compressing the existing vapor or when
increasing temperature causes increased evaporation
or expansion of existing vapor. Conversely, vacuum
may be created when pumping out or decreasing
temperature. To prevent damage, vapor must be
allowed to escape or enter the tank at a specified
pressure or vacuum. The volume rate of venting
depends upon the tank size, volatility of the contents,
the pumping rate and the temperature. See API
Standard 2000 for the procedure for determining
venting requirements.
The pilot operated relief valve has two principal
advantages over other types of relief valves:
1). It is bubble tight at 10% below set pressure.
2). It is fully open at 10% above set pressure.
These characteristics permit operating pressures
nearer to the maximum allowable working pressure
of the tank. High operating pressures reduce
evaporation and total venting volume, thereby
reducing product loss and cost of processing
emissions. A tank may also have provisions for
emergency pressure relief due to fire exposure and/or
inert gas blanketing of the vapor space. A typical
tank installation is shown in Figure 1 which includes
a pilot operated pressure/vacuum relief valve, a gas
blanketing regulator and an emergency pressure
relief valve. The emergency valve may also be pilot
operated. Groth Corporation manufactures all of
these devices.
The pilot valve must be carefully maintained by a
knowledgeable valve technician. It should only be
assembled under clean conditions, preferably in a
service shop environment. Carefully read and
understand this manual before attempting to adjust
set pressure or blowdown, or repair the pilot valve.
Groth Corporation offers repair services for all
products manufactured by The Tank Protection
Division.
1
PILOT OPERATED
PRESSURE/VACUUM
RELIEF VALVE
GROTH MODEL 1420
EMERGENCY RELIEF VALVE
GROTH MODEL 2400
Figure 1: Tank Installation - Safety Equipment
GAUGE
BLANKET GAS REGULATOR
GROTH MODEL 3000
BLANKET
GAS
SUPPLY
SENSE LINE
PILOT VALVE DESIGN AND
FUNCTION
Note that throughout this manual, numbers in [ ] after
the part descriptions are item numbers which refer to
the drawings and bill of materials.
The function of the pilot valve is to co ntrol pressure
to the actuator of a pressure relief valve. The
pressure relief valve is designed so the effective area
of the actuator (1) is significantly larger than the
valve seat area (2). Therefore when tank pressure is
applied to the actuator, the closing force is greater
than the opening force so tight shut-off is achieved.
The pilot seat is held closed by the adjustable set
pressure spring. Tank pressure is conveyed to the
pilot valve by the pilot pickup tube (3), and directly
applied to the booster diaphragm (4).
Simultaneously pressure is applied through an
adjustable orifice (6) to the space between the
diaphragms and to the pressure relief valve actuator,
closing the relief valve. The net force attempting to
lift the pilot spool is the tank pressure acting on the
effective area of the sense (smaller) diaphragm (5).
Fig. 2 Shut - Off Condition
5
4
7
3
6
8
1
2
2
When the tank pressure reaches the set pressure of
the pilot valve, force on the diaphragm overcomes
the spring and vapors begin to flow to the
atmosphere through the pilot seat (7) and exhaust
port (8). As the actuator is evacuated to atmosphere,
pressure is also reduced in the space between the
diaphragms, and additional lifting force is provided
by the booster (larger) diaphragm. The rate of
evacuation of the actuator is controlled by the
diameter of the adjustable orifice. As pressure on the
actuator is relieved, tank pressure forces the relief
valve seat (2) fully open.
As tank pressure decreases to the pilot valve setting,
the valve closes and tank pressure again flows
through the orifice to the relief valve actuator. As the
actuator is filled, the pressure relief valve seat is
forced closed. The size of the adjustable orifice
determines the speed of filling the actuator.
The adjustable orifice, or "blowdown needle", affects
both opening and closing of the pressure relief valve.
Opening can be varied from rapid, "snap action", to
incremental, "modulating". The pressure at which
the valve closes, "blowdown pressure", can vary
from set pressure to 7-10% below set pressure.
These characteristics are discussed in detail in the
operation section of this manual.
TABLE 1
PILOT VALVE SPECIFICATIONS
MODEL 1401E
Set pressure 2.0" WC to 15 PSIG
5 to 1033 mbar (metric)
Blowdown Zero to 10 %
Action "Snap Action" to
"Modulating"
Materials Carbon Steel/SS Trim
316 SS
Diaphragm Fluoropolymer
Elastomers Buna-N, FKM, FFKM
WARNING
The pilot valve will exhaust the actuator of the
pressure relief valve as described in this manual.
This function does NOT assure that the relief valve
will open fully. The forces exerted by system
pressure and vapor flow must be sufficient to support
the weight of the pallet-support assembly to achieve
full opening. Relief valves built with heavy
components designed to withstand high pressure may
NOT open at low pressure even though the actuator
has been fully exhausted. Consult Groth
Corporation or the specific relief valve operation
manual when applying pilot operated pressure relief
valves at low pressure settings.
Eight springs are used with the screw adjustment to
obtain the required set pressure. For more detail see
Table 2 on page 5.
This manual is intended to provide recommended
procedures and practices for installation, operation,
and maintenance of the Groth Series 1401E Pilot
Valve. The pressure relief valve is covered by a
separate manual. 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, reliable pilot
valve performance.
For information not contained in this manual, please
contact:
Groth Corporation
13650 N. Promenade Blvd.
Stafford, Texas 77477
281-295-6800 (phone)
281-295-6995 (fax)
SAFETY GENERAL INSTRUCTIONS
This section is an overview of safety guidelines that
should be followed during the installation, operation
and maintenance of Groth series 1401 pilot valves.
To understand the context of these instructions and
warnings, read and understand this complete manual.
WARNING
The purpose of a pilot operated pressure relief valve
is to prevent excessive pressure or vacuum in a tank
or process system. The valve must be designed for
the proper MAWP and flow requirements of the
system. Consult API Standard 2000 for tank
protection sizing procedures. An improperly
specified or functioning relief valve may result in
structural damage to the tank or system.
In the event of a diaphragm failure, the pilot valve
will vent pressure to the atmosphere, causing the
pressure relief valve to fail in the OPEN position.
Pressure may be vented slowly, simulating the action
of a modulating pilot. Under these conditions,
somewhat greater overpressure may be required to
produce the full flow capacity of the relief valve.
3
Pilot valve set pressure and blowdown are set at the
factory per purchase specifications. Th e set pressure
and range of adjustability are stamped on the
nameplate. DO NOT attempt to readjust the set
pressure beyond the limits specified on the nameplate
and in Table 2.
The pilot sense line is 3/8" OD SS tubing. It must be
kept open and unobstructed to ensure that the pilot
"senses" actual tank pressure. For applications
where tank vapors may condense or "polymerize" in
the sense tube or pilot valve, a nitrogen purge may
be required to prevent internal obstruction of the
tube. Consult Groth Corporation for
recommendations.
DO NOT attempt to remove the pilot valve from the
pressure relief valve without removing or isolating
the relief valve from the system. ALTERNATIVE
MEANS OF PRESSURE RELIEF MUST BE
PROVIDED WHEN THE VALVE IS OUT OF
SERVICE. After isolating the relief valve, bleed all
pressure from both relief and pilot valves before
removing the pilot valve.
Both pilot and pressure relief valve are exposed to
process vapors. Observe all plant procedures and
Material Safety Data Sheets for the products in the
system when inspecting, adjusting or servicing the
valves. Vents on the body and spring bonnet of the
pilot valve must be clean and unobstructed for
proper and safe operation of the valve. These vents
should be inspected periodically. Back out set
pressure adjusting screw to relieve all spring
pressure before removing the spring bonnet.
Blowdown needle chamber is exposed to system
pressure. The screw may be adjusted from nearly
contacting the seat (screw bottomed out) for snap
action to partially retracted for maximum
modulation. The screw is retained by the blowdown
bushing. DO NOT remove the blowdown bushing
while under pressure.
The tank pressure required to discharge the normal
or emergency venting requirements of the tank will
be increased by the amount of back pressure in the
discharge header. Maximum possible discharge
header pressure must be considered when sizing the
pressure relief valve.
INSPECTION AND INSTALLATION
The pilot valve or pilot operated pr essure relief valve
is packaged and supported to prevent damage or
contamination during 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 valve
must be disassembled, cleaned and inspected before
installation. The spring adjustment cap and
blowdown screw locknut must be secure. Report any
shipping damage to your carrier.
The pilot valve is installed on the top port of the
relief valve actuator with a 1/2" Sch. 40 pipe nipple
of minimum length and material suitable for the tank
contents. There should be no block valve or other
restriction between the pilot valve and the actuator.
Wrap all pipe threads with fluoropolymer tape or
apply a suitable pipe thread sealant sparingly. Before
connecting sense line, backflow compressed air
through line and pick-up fitting in relief valve to
assure that no obstruction exists. Connect sense line
to relief valve and pilot valve with no in-line block
valve or other restriction. If a check valve is used in
the sense line for backflow prevention, make sure it
is unrestricted and installed with the correct flow
direction (Fig 8). The same procedures and
precautions apply if a remote sense line is used.
Field test connection, manual/remote blowdown and
pilot discharge connections, if applicable, must be
connected according to the Fig. 8, 9 and 10. Set
pressure and blowdown adjustment may be done on
the test bench (following the procedure on page 11)
or on the relief valve. The initial set pressure and
spring range can be found on the pilot valve
nameplate.
OPERATION
Both relief pressure and blowdown are set at the
factory to comply with the specification on the
purchase order. If blowdown is not specified, snap
action with 7-10% blowdown will be furnished. The
range of adjustment will depend on the spring
installed and will be stamped on the nameplate. The
pressure setting may be changed within the designed
range either while on line or in a service shop.
Observe the proper setting and testing procedure in
this manual.
4
M
M
WARNING
The recommended set pressure range is stamped on
the nameplate. Never adjust a spring for a set
pressure beyond its upper or lower design limit as
specified on the nameplate and in Table 2.
Exceeding the upper limit may compress the spring
beyond its working height and the pilot valve may not
open fully. A valve set below the lower limit will
require excessive overpressure to open fully. In
either case, the pressure relief valve may not provide
sufficient capacity to prevent overpressure and
failure of the tank.
TABLE 2
SPRING TABLE
Spring
Range
1 2.0-4.0" WC Yellow 81631001
2 4.1-8.0" WC Green 81631002
3 8.1-16.0" WC Pink 81631003
4 16.1-28.0" WC Blue 81631004
5 1.1-2.0 PSI White 81631005
6 2.1-4.0 PSI Gray 81631006
7 4.1-8.0 PSI Black 81631007
8 8.1-15.0 PSI Red 81631008
The following are the normal operating phases of the
pilot valve:
ORIFICE
Set
Pressure
Fig. 3 Closed Position
LOWDOWN
Color
SENSE
DIAPHRAG
BOOSTER
DIAPHRAG
Part No.
(smaller) diaphragm and is insufficient to overcome
the spring force.
Tank pressure has filled the relief valve actuator
(dome) through the sense line and the adjustable
orifice. The relief valve is tightly closed. When the
tank pressure increases to the point that the net
opening force equals the spring force, the pilot valve
will begin to open.
Fig. 4 Open - Snap Action
The pilot valve begins to open at set pressure with
the blowdown orifice set for snap action (minimum
area). The space between diaphragms exhausts to
atmosphere and the net effective lifting force is the
system pressure acting on the booster (larger)
diaphragm. The additional lifting force caused the
pilot to open fully. The actuator exhausts rapidly
through the fully open pilot valve. The relief valve
opens fully at approximately 10% overpressure and
system pressure begins decreasing immediately.
Fig. 5 Open - Modulating
TANK
PRESSURE
ATMOSPHERE
DOME
PRESSURE
The tank pressure is less than set pressure and the
pilot valve is closed. Since the pressure between the
diaphragms is equal to the pressure under the booster
diaphragm, the net force on the booster (larger)
diaphragm is zero. Therefore, the net effective
opening force is the tank pressure acting on the sense
The pilot valve begins to open at set pressure with
the blowdown orifice set for maximum modulating
action (increased orifice).
5
WARNING
Increase the orifice setting only enough to provide
the desired modulating action. Excessive orifice size
will prevent the pressure relief valve from opening
fully at the specified overpressure.
Because of the high flow rate through the orifice, the
pressure under the lower diaphragm decreases
slightly and the pressure between diaphragms
exhausts slowly so the pilot valve opens partially.
The actuator exhausts slowly through the partially
open pilot valve and the relief valve opens slowly.
The pilot valve will open incrementally and the
actuator will be exhausted sufficiently to satisfy flow
requirements without excessive overpressure. The
relief valve will maintain the system at approximately
10% overpressure until the source of the
overpressure ceases.
Fig. 6 Reseat - Snap Action
Fig. 7 Reseat - Modulating
When the tank pressure decreases to set pressure with
the pilot valve set for minimum blowdown (increased
orifice) the pilot valve begins to close. Because of
the high flow of tank vapors, the pressure between
diaphragms increases rapidly, the pilot valve closes
rapidly, and the relief valve actuator fills rapidly.
The relief valve closes at a pressure very near the set
pressure, achieving "zero blowdown".
OPTIONS
The following options are frequently utilized to
reduce vapor emissions, improve serviceability or
expand the capabilities of the pressure relief valve:
Fig. 8 Vent Piped to Discharge Header
When the tank pressure decreases to set pressure with
the pilot valve set for maximum blowdown
(minimum orifice) space between diaphragms is still
evacuated. Set pressure is acting on a larger
effective diameter and the valve remains open. The
pilot valve begins to close at a lower pressure.
Because of the low flow of tank vapors, the pressure
between diaphragms increases slowly so the pilot
valve closes slowly, and the relief valve actuator fills
slowly. The relief valve closes at a pressure less than
set pressure which is relative to the orifice
adjustment.
6
At any time that the tank pressure is greater than the
set pressure, the pilot valve will exhaust vapor s from
the tank and/or from the relief valve actuator. If
exhausting to atmosphere is not acceptable, the pilot
valve discharge can be piped into the relief valve
discharge flange. Back pressure in the header will
have negligible effect on the operation of the pilot
valve, but if too high it may prevent the relief valve
actuator from opening fully.
Contact Groth Corporation if you plan to discharge
the pilot into a header with back pressure. A check
valve may be required to prevent header vapors
backflowing into the tank.
WARNING
The tank pressure required to discharge the normal
or emergency venting requirements of the tank will
be increased by the amount of back pressure in the
discharge header. Maximum possible discharge
header pressure must be considered when sizing the
pressure relief valve.
Fig. 9 Field Test Connection
A test connection with an isolation valve is provided
at the sense port of the pilot valve and a check valve
is installed in the sense line. Then an independent
pressure source (such as a portable nitrogen bottle
with the proper flow controls and pressure measuring
instruments) can be used to open the pilot valve and
measure the set pressure. The test medium will not
enter the tank, however tank vapors will be
discharged during the setting procedure.
Groth Corporation can supply the complete test
apparatus, including nitrogen bottle and
instrumentation, if desired.
Fig. 10 Manual/Remote Blowdown
A field test connection may be supplied for the
purpose of testing and setting the pilo t valve in line
without increasing tank pressure.
A local or remote, manual or solenoid operated
blowdown valve provides the capability of opening
the relief valve without opening the pilot valve.
Either a manual or electrically operated valve may be
mounted either at the relief valve location or
remotely. The valve is used to discharge the relief
valve actuator to atmosphere or to a process vapor
discharge system. This option allows the pressure
relief valve to be used as a control valve for
discharging tank vapors.
7
TROUBLESHOOTING GUIDE
PROBLEM
Vapor flowing at tank
pressure below specified
set point.
Vapor not flowing at
tank pressure above
specified set point.
Vapor leaking from
spring bonnet vent
Vapor leaking from body
vent
Incorrect blowdown
pressure
Visual, audible or
vapor detector
Visual, audible or
vapor detector
Visual, audible or
vapor detector
Visual, audible or
vapor detector
Visual, audible or
vapor detector
INSPECTION
RECOMMENDED SPARE PARTS
When ordering spare parts, include model and serial
number of the valve, pressure setting, blowdown
setting and required material for soft goods.
TABLE 3
RECOMMENDED SPARE PARTS
Item Description Qty
15 Diaphragm, actuator 2
40 Diaphragm, body 1
19 O-Ring, blowdown 1
28 O-Ring, stem 1
27 O-Ring, seat 1
32 O-Ring, disc 1
35 Gasket, spring bonnet 1
41 Gasket, body 1
10 Gasket, actuator 2
25 Washer, spacer 3
22 Stem 1
26 Screw, stem 1
34 Bushing, seat 1
33 Disc 1
20 Needle, blowdown 1
30 Spacer, central 1
17 Screen, filter 1
SUGGESTED CORRECTIVE ACTION
Check actual set pressure on tank if field test connection is
installed. Otherwise remove unit and test for: Incorrect
pressure and blowdown setting using setting and testing
procedure in this manual. Damaged seals, seat or
diaphragms. Damaged spring or other components.
Foreign material or corrosion in pilot.
Check actual set pressure on tank if field test connection is
installed. Otherwise remove unit and test for: Incorrect
pressure and blowdown setting using setting and testing
procedure in this manual. Plugged sense line or internal
orifices. Foreign material or corrosion in pilot.
Ruptured diaphragms; remove and replace.
Damaged seal, seat or body diaphragm, or stem O-Ring.
Remove and replace.
Remove and set according to setting and testing procedure
in this manual.
MAINTENANCE
The 1401E pilot does not require routine lubrication
or adjustments. It should be checked periodically, at
least once a year, to confirm the valve is functioning
properly and that the set point is correct. The pilot
valve is a fail safe device because failure of any seals
or diaphragms will cause pressure to be vented to
atmosphere, thereby allowing the pressure relief
valve to open under pressure.
Groth Corporation strongly recommends that all
service performed on a pilot operated valve be done
at the factory or a factory authorized repair center.
Trained mechanics with specialized test equipment
will ensure that the valve is accurately set. Flow
capacity can be measure at the specified overpressure condition, if specified on the purchase order.
CAUTION
If the valve must be disassembled for any reason,
first make sure all pressure to the valve is blocked
and pressure trapped in the valve vented safely.
Refer to your company procedures when handling
toxic or other hazardous materials.
8
S
TOOLS:
All service, adjustment and assembly on the pilot
may be performed with the following common tools:
7/16", 1/2", 9/16", 11/16"
and adjustable wrench
Flat blade screwdriver
9/64" Hex socket key
7/8", 3/4" Deep socket
WARNING
The pilot diaphragm actuator housing and the valve
body are exposed to the process vapor. Observe all
standard safety precautions as specified on Material
Safety Data Sheets for the product(s) in the system
both while removing the valve and while repairing it.
DISASSEMBLY
To disassemble the pilot, first unload the spring by
removing the cap [1] and turn the adjustment screw
[2] counterclockwise until all spring compression has
been released. Remove (4) hex bolts [8] and remove
the spring bonnet [4]. Remove the spring and button.
Remove (12) hex bolts [12,13 & 14] and remove the
upper actuator housing [9] and gasket [10]. Remove
the stem nut [23] and stem assembly components:
[24, 29, 28, 37, 25, 15, 11, 30, 38, 15, 25, 31, 25 &
10]
Remove (8) hex bolts [16], the lower actuator
housing [39], body diaphragm [40], gasket [41] and
stem assembly. Remove socket cap screw [26] from
stem assembly. Remove seat bushing [34], jam nut
[21], blowdown needle [20] and blowdown bushing
[18]. Remove bug vent [7] from body and spring
bonnet. Replace worn or damaged components.
When a part is replaced, make sure the material is
suitable for the service, especially elastomer parts. If
an O-Ring needs to be replaced, be sure to use the
correct size and material. Prior to reassembly, make
sure all parts are clean and free of contamination.
ASSEMBLY
Before assembly, note the following material and tool
requirements:
1. Spare parts as listed in table 3.
2. Lubricants and thread sealants
Silicon Grease - Dow Corning No. 33
Fluoropolymer Tape
3. Assembly tools
7/16", 1/2", 9/16", 11/16"
and adjustable wrench
Flat blade screwdriver
9/64" Hex socket key
7/8", 3/4" Deep socket
TABLE 4
RECOMMENDED BOLT TORQUE
[Ft. - Lb.]
Bolt Size 1/4" 5/16" 3/8" 7/16" 1/2"
Torque 6 11 20 32 44
Use fluoropolymer tape or anti-seize compound on
pipe thread joints. Use lubricant sparingly on other
screw threads. Do not over tighten threaded
connections. Damage or breakage may result.
Assemble with special attention to the exploded view
drawing on page 13.
Retract the blowdown needle [20] into the bushing
[18] to avoid damage to the needle and/or body, then
screw the bushing into the body. Tighten the bushing
firmly since it forms a metal to metal seal against the
body. Replace the fluoropolymer O-Ring [19] if it is
damaged. Install the O-Ring on the blowdown
needle and thread the jam nut [21] to help slide the
O-Ring into the groove on the bushing. Tighten the
jam nut against the bushing to squeeze the
fluoropolymer O-Ring into place. This will cold
form the O-Ring into the blowdown needle threads
and create an effective seal. Back off the jam nut and
adjust the needle as mentioned under
"OPERATION".
Fig. 11 Body Sub - Assembly
42
A
7
ECTION A-A
27
34
A
17
18
19
20
21
9
The seat bushing [34] forms a metal to metal seal
against the body. Make sure the sealing surfaces are
smooth and the seat bushing torqued down firmly.
Replace the seat O-Ring [27] if it is damaged.
Replace filter [17] if it is damaged or plugged. Place
filter inside inlet port and use a 1/2" diameter round
bar or similar tool and push filter into place. Do not
hammer in or damage may result. Install the bug
vent but do not tighten until after testing. Place body
gasket [41] on top of body [42] and align with all
nine holes in body.
The disc [33] seals against the soft seat and it has a
polished finish. The finish must be free of nicks and
scratches. Recondition disc if sealing surface finish
is damaged. Place on lapping machine until nicks
and scratches are removed. If the disc is
fluoropolymer coated, the coating must be smooth
and not chipped. Replace the disc if coating is
damaged. Place a small amount of lubricant in the
ball cavity. Install O-Ring [32] outside of the ball
cavity. Attach the disc to the stem with the stem
screw [26]. Use a 9/64" hex key to tighten the screw.
Do not over tighten the screw or swiveling will be
eliminated, causing leakage due to disk/seat
misalignment. Position stem assembly in the body
cavity. Slip body diaphragm [40] on stem assembly
and place on top of body gasket. Properly align with
all nine holes in gasket and body. Place the lower
actuator housing [39] over the body diaphragm and
align with all nine holes and the stem. Install the
eight hex bolts [16], and tighten. Place the gasket
[10] on the lower actuator housing. Stack the
components over the stem in the following order:
Lower fluoropolymer washer [25]
Lower spacer [31]
Another fluoropolymer washer [25]
Lower diaphragm [15]
Lower support plate [38]
Central spacer [30]
Spacer [11]
Upper diaphragm [15]
Fluoropolymer washer [25]
Upper support plate [37]
O-Ring [28]
Spring guide [29]
Make sure the step of the guide is centered
in the hole of the support plate.
Lock washer [24]
Hex nut [23]. Do not tighten hex nut.
Gasket [10]
Upper diaphragm case [9]
Align all holes on the gasket, the upper diaphragm,
the spacer ring, the lower diaphragm, and the gasket,
with the lower diaphragm case. Install the (12) bolts
[12], with the lock washers [14], the hex nuts [13],
and tighten.
Fig. 12 Stem Sub - Assembly
23
22
28
29
30
31
32
33
Now tighten the stem nut. A wrench should be used
to hold the flats at the tip of the stem while the nut
[23] is being tightened to prevent torque on the
diaphragms. Place the spring [6] on top of the spring
guide [29]. Then the spring button [5]. Place a small
amount of grease in the cup of the button where the
adjustment screw point will be bearing.
Place the gasket [35] on top of the upper actuator
housing [9]. Then the spring bonnet [4] with the bug
vent [7]. Install the hex bolts [8] and tighten evenly.
Lightly grease and thread the adjustment screw [2]
and the jam nut [3] on the spring bonnet. Reset the
pilot valve to the desired set point within the set
range of the spring. See the setting and testing
section of this manual. Tighten jam nut after setting
is achieved. And finally install the cap [1].
24
37
38
15
25
40
26
NOTE
The pilot valve may be pre-set independent of the
pressure relief valve if suitable setting equipment is
available. If equipment is not available, the pilot
must be reinstalled on the relief valve and the pilot
set by pressurizing the relief valve inlet. Field testing
may be accomplished if the relief valve assembly is
equipped with the required test connections. See the
setting and testing section of this manual.
10
SETTING AND TESTING PROCEDURE
S
L
R
E
SERIES 1401 PILOT VALVES
TESTING PILOT VALVE ALONE
NOTE: See pressure relief valve manual for procedure for
setting and testing the pilot valve/relief valve assembly.
1.0 Equipment
1.1 Test apparatus per Fig. 13.
1.2 Test gauges must be selected to suit the specified set
pressure. The set pressure should be between 20% and
80% of the full scale reading of the gauge.
2.0 Test procedure and acceptance criteria
2.1 To determine set pressure, slowly increase pilot inlet
pressure. Simulated actuator pressure will rise with inlet.
As set pressure is approached, the actuator pressure will
begin to decrease. Continue to increase inlet pressure
slowly until actuator pressure is 15% (+/- 10%) of inlet
pressure. This is the set pressure.
2.2 Rotate set pressure adjusting screw [2] clockwise to
increase set pressure or counter clockwise to decrease.
Adjust screw and repeat above test (2.1) until the specified
set pressure is achieved.
2.3 To determine reseat pressure, slowly decrease the inlet
pressure and the actuator pressure will begin to increase.
Reseat occurs when the actuator pressure equals the inlet
pressure.
2.4 The difference between set and reseat pressure,
"blowdown", can be adjusted with the blowdown needle
[20]. Maximum clockwise rotation provides rapid relief
valve opening, "snap action", and maximum blowdown.
Standard blowdown, unless otherwise specified is 7-10% of
set pressure.
2.5 Increased counter clockwise rotation of blowdown
screw provides "modulating" action and minimum (zero)
blowdown. Reseat pressure is the same as set pressure.
NOTE: The blowdown needle is located in a pressure
containing chamber, and is retained by the blowdown
bushing. DO NOT remove the blowdown bushing while
under pressure.
2.6 Remove body vent and install a flexible tube in this
port. Immerse this pilot discharge bubble tube in water
approximately 1/4" below surface to detect cracking and
reseat pressure. See Warning on page 6.
2.7 A small interaction occurs between set pressure and
blowdown adjustments. Readjustment of both may be
required until the specified set pressure and blowdown are
achieved. After completion, lock both screws with
locknuts and replace cap on set pressure screw.
2.8 Hold the valve at set pressure while soap bubble
testing all bolted, flanged and threaded connections.
2.9 Standard setting specifications
SETTING SPECIFICATIONS - PILOT VALVE
Pilot
Action
Snap 2"-8" WC +/- 0.2" 75 90 +/- 3
Snap 8" WC -
Snap 1.0 - 15.0
Modulating 2" - 8" WC +/- 0.2" 75 100
Modulating 8" WC -
Modulating 1.0 - 15.0
Set
Pressure
1.0 PSIG
PSIG
1.0 PSIG
PSIG
TABLE 5
Set
Pressure
Limits
+/- 3% 90 90 +/- 3
+/- 3% 95 93 +/- 3
+/- 3% 90 100
+/- 3% 95 100
Maximum
Cracking
Pressure
% of Set
3.0 Test report data
3.1 Record the following data for future reference:
Model, tag & serial numbers
Test medium
Set pressure
Blowdown pressure
Cracking pressure
Bubble tight reseat pressure
Fig. 13 Pilot Valve Alone
ET PRESSURE
ACTUATO
PRESSUR
AIR
UPPLY
ACTUATOR VESSEL
APPROX 0.1 CU FT
25 PSI MAWP
11
Reseat
Pressure
% of Set
BILL OF MATERIAL
MODEL 1401E
ITEM QTY DESCRIPTION
CARBON
1 1 CAP-ADJUSTMENT SCREW C STL ALUM 303 SS 303 SS
2 1 SCREW-ADJUSTMENT 304 SS 304 SS 304 SS 304 SS
3 1 HEX NUT 316 SS 316 SS 316 SS 316 SS
4 1 BONNET-SPRING C STL ALUM 316 SS 316 SS
5 2 BUTTON-SPRING 303 SS 303 SS 303 SS 303 SS
6 1 SPRING CR VA STL OR 316 SS
7 2 BUG VENT ALUM ALUM ALUM ALUM
8 4 HEX BOLT 316 SS 316 SS 316 SS 316 SS
9 1 ACTUATOR HOUSING, UPPER C STL ALUM 316 SS 316 SS
10 2 GASKET, ACTUATOR FEP
11 1 SPACER-ACTUATOR HOUSING C STL ALUM 303 SS 316 SS
12 12 HEX BOLT 316 SS 316 SS 316 SS 316 SS
13 12 HEX NUT 316 SS 316 SS 316 SS 316 SS
14 12 LOCK WASHER 316 SS 316 SS 316 SS 316 SS
15 2 DIAPHRAGM-ACTUATOR FEP
16 8 HEX BOLT 316 SS 316 SS 316 SS 316 SS
17 1 SCREEN-FILTER 316 SS 316 SS 316 SS 316 SS
18 1 BUSHING-BLOWDOWN 303 SS 303 SS 303 SS 316 SS
19 1 O-RING #012 FLUOROPOLYMER
20 1 NEEDLE-BLOWDOWN 304 SS 304 SS 304 SS 316 SS
21 1 HEX NUT-JAM 316 SS 316 SS 316 SS 316 SS
22 1 STEM 303 SS 303 SS 303 SS 316 SS
23 1 HEX NUT 316 SS 316 SS 316 SS 316 SS
24 1 LOCK WASHER 316 SS 316 SS 316 SS 316 SS
25 3 WASHER FEP
26 1 SCREW-STEM 316 SS 316 SS 316 SS 316 SS
27 1 O-RING-SEAT, #111 70 DURO AS SPECIFIED
28 1 O-RING-STEM, #010 70 DURO AS SPECIFIED
29 1 GUIDE-SPRING 303 SS 303 SS 303 SS 316 SS
30 1 SPACER-CENTRAL 303 SS 303 SS 303 SS 316 SS
31 1 SPACER-LOWER 303 SS 303 SS 303 SS 316 SS
32 1 O-RING-DISC, #012 70 DURO AS SPECIFIED
33 1 DISC-STEM 303 SS 303 SS 303 SS 316 SS
34 1 BUSHING-SEAT, 303 SS 303 SS 303 SS 316 SS
35 1 GASKET-SPRING BONNET BUNA-N
36 4 SWAGE NUT 316 SS 316 SS 316 SS 316 SS
37 1 PLATE-SUPPORT, UPPER 316 SS 316 SS 316 SS 316 SS
38 1 PLATE-SUPPORT, LOWER 316 SS 316 SS 316 SS 316 SS
39 1 ACTUATOR HOUSING, LOWER C STL ALUM 316 SS 316 SS
40 1 DIAPHRAGM-BODY FEP
41 1 GASKET-BODY FEP
42 1 BODY 303 SS 303 SS 303 SS 316 SS
MATERIALS OF CONSTRUCTION
STEEL
ALUMINUM STAINLESS
STEEL
316 SS
12
Fig. 14 - Model 1401E Pilot Valve - Exploded Assembly
1
35
3
2
4
8
7
5
6
12
9
36
25
10
30
15
31
16
11
38
39
14
13
15
10
24
29
23
28
25
37
13
40
22
32
33
26
34
7
20
41
27
42
17
19
21
18
Fig. 15 - Model 1401E Pilot Valve - Cross Sectional Assembly
28
29
30
31
32
33
34
STEM/SEAT
DETAIL
35
36
37
38
22
23
24
25
26
27
1
2
3
4
5
6
7
8
9
10
11
39
4140
42
7
A
A
SECTION A-A
12 13 14
15
16
17
18
19
20
21
14
The nameplate on the Groth Series 1401 Pilot Valve contains the model number, serial number, set pressure and set
pressure range. The model number contains additional information about materials of construction, capacity and
options. The following chart will assist in relating the model number to the specifications of your pilot valve:
Spring Range Soft Goods Material
English
2.0"- 4.0" WC
1
4.1" - 8.0" WC
2
8.1" - 16.0" WC
3
16.1" - 28.0" WC
4
1.1 - 2.0 PSI
5
2.1- 4.0 PSI
6
4.1 - 8.0 PSI
7
8.1 - 15.0 PSI
8
Metric
5 - 10 mbar
11 - 20 mbar
21 - 40 mbar
41 - 69 mbar
70 - 138 mbar
139 - 275 mbar
276 - 550 mbar
551 - 1020mbar
B
E
V
K
Z
Buna-N
EPR
FKM
FFKM
Special
1
Aluminum
3
Carbon Steel
4
Stainless Steel
9
316 SS
Z
Special
Model 1401EL 2.0" - 4.0" WC
Model 1401E 4.0" WC - 15 PSI
A "Z" in the model number indicates a non-standard material or feature. Review your purchase specifications or
consult Groth Corporation for more details.
EXAMPLE 1401E 2 V 4 Indicates a 1401E Series Pilot Valve with:
Set Pressure Range from 4.1" WC - 8.0" WC,
FKM Elastomers, SS Construction, and No
Special Requirements.
PRODUCT LIMITED WARRANTY
A.
Seller warrants that products which are manufactured by Seller, are manufactured in accordance with published
specifications and free from defects in materials and/or workmanship for a period of (12) twelve months. Seller, at its
option, will repair or replace any products returned intact to the factory, transportation charges prepaid, which Seller, upon
inspection, shall determine to be defective in material and/or workmanship. The foregoing shall constitute the sole remedy
for any breach of Seller's warranty
B. THERE ARE NO UNDERSTANDINGS, AGREEMENTS, REPRESENTATIONS, OR WARRANTIES, EXPRESS OR
IMPLIED, (INCLUDING MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE REGARDING
PRODUCTS ) UNLESS SPECIFIED IN THE SALES CONTRACT . THIS CONTRACT STATES THE ENTIRE
OBLIGATION OF SELLER.
Seller makes no warranties, either express or implied, except as provided herein, including without limitation thereof,
warranties as to marketability, merchantability, for a particular purpose or use, or against infringement of any patent of
products. In no event shall Seller be liable for any direct, incidental or consequential damages of any nature, or losses or
expenses resulting from any defective new product or the use of any such product, including any damages for loss of time,
inconvenience, or loss of use of any such product.
C. The original Manufacturer shall be solely responsible for the design, development, supply, production, and performance of
its products hereunder, and the protection of its trade name or names, if any. It assumes no responsibility, for products
modified or changed in any way by its agent or customer. Any such modifications or changes to products sold by Seller
hereunder shall make the product limited warranty null and void.
D. The Manufacturer shall be under no obligation to manufacture, sell, or supply, or to continue to manufacture, sell or supply
any of the Products.
15
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