Groth 2000A User Manual

Installation, Operation and Maintenance Manual for

Emergency Relief Valve

Models 2000A, 2050A, 2400A, 2450A

IOM2000A.4

Rev. A 12541

© 2008 Groth Corporation

TABLE OF CONTENTS:

INTRODUCTION: 2
DESIGN, FUNCTION & OPERATION 3
GENERAL SAFETY INSTRUCTIONS 4
SAFETY WARNINGS 4
INSPECTION AND INSTALLATION 5
PREVENTIVE MAINTENANCE 6
MODEL 2000A DISASSEMBLY & ASSEMBLY 7
MODEL 2000A DISASSEMBLY & ASSEMBLY 7
MODEL 2050A DISASSEMBLY & ASSEMBLY 8
MODEL 2400A DISASSEMBLY & ASSEMBLY 12
MODEL 2450A DISASSEMBLY & ASSEMBLY 13
TESTING AND SETTING PROCEDURE 17
MODEL INFORMATION 13
PRODUCT LIMITED WARRANTY 13

INTRODUCTION:

Groth’s Emergency Relief Valve (ERV) is designed to provide emergency relief capac ity beyond that furnished by
the normal operating pressure relief valve on the tank. T hey are used on liquid storage tanks and other process
vessels or systems to prevent structural damage due to excess internal pressure or vacuum that could result under
emergency situations due to fire exposure or failure of the inert gas blanketing system.

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 due to decreasing temperature. To prevent damage, vapor must be al lowed to escape or ent er
the tank at a specified pressure or vacuum condition. 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 procedures to
determine venting requirements.

The valves are designed to be self closing under normal operation. As excessive pressure builds up, the valve
relieves and then reseats when over pressure has been dissipated. Some models have a restraining cable to
connect the head and flanges and also serve as a grounding cable.

The pallets include Groth's special "cushioned air" seating. FEP seating diaphragms are standard; they minimize
sticking caused by resinous vapors and atmospheric moi sture. Diaphragms are also available in Buna-N, FK M and
other elastomers. Peripheral guides insure proper alignment and integrity of the seating.

The ERVs are preset at the factory in accordance with the purchase or der's instructions. These settings are printed
on the stainless steel name tag.

The valve must be 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 installing or repairing
this valve.

For information not contained in this manual, please contact:

Groth Corporation

13650 N. Promenade Blvd

Stafford, TX 77477

281-295-6800 (Phone)

281-295-6995 (Fax)

2

DESIGN, FUNCTION & OPERATION

The 2000A Series was designed as a cost effective valve that would protect a tank by providing
emergency pressure relief caused by fire or other factors that could make the pressure rise.
Groth manufactures four models in this series [Table 1] for pressure relief; two models also
provide vacuum relief.

Table 1 : Model Identification

Model Pressure Vacuum Description
2000A Y Guided Cover
2050A Y Y Guided Cover w/ vacuum relief
2400A Y Hinged Cover
2450A Y Y Hinged Cover w/ vacuum relief

Model 2000A provides pressure relief only; vacuum relief must be supplied by a separate
breather valve. Model 2050A provides pressure relief and vacuum relief through a spring
loaded port integral to the cover assembly. A weatherhood and screen are provided for
protection.

Model 2400A incorporates a hinged pivot point for the cover, providing additional alignment for
the cover so it reseats properly after venting. The Model 2450A adds vacuum relief capability
while keeping the hinge design. The hinged design closes after relieving pressure or vacuum.

All valve covers can be lifted off the base, providing quick access for tank inspection and
maintenance. Note: Depending on pressure setting, it may be necessary to use a crane or
other lifting device to open or remove the cover assembly. A typical tank installation is shown in
Figure 1 which includes a Pilot Operated Pressure/Vacuum Relief Valve, a Gas Blanketing
Regulator and the 2000A Emergency Relief Valve which provides emergency pressure relief.
Groth Corporation manufactures all of these devices.

Figure 1: Tank Installation - Safety Equipment

3

GENERAL SAFETY INSTRUCTIONS

This section is an overview of safety guidelines that should be followed during the installation, operation and
maintenance of Groth Pressure / Vacuum Relief Valves. To understand the context of these instructions and
warnings, it is necessary to completely read and understand the contents of this manual.

The purpose of a pressure/vacuum 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 functio ning relief valve may result in
structural damage to the tank or system, and can cause severe personal injury or death.

SAFETY WARNINGS

THE PURPOSE OF AN EMERGENCY RELIEF VALVE (ERV) IS TO PREVENT EXCESSIVE PRESSURE IN A

TANK OR PROCESS SYSTEM UNDER EMERGENCY SITUATIONS. 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 EMERGENCY
RELIEF VALVE MAY RESULT IN STRUCTURAL DAMAGE TO THE TANK OR SYSTEM AND SEVERE
PERSONAL INJURY OR DEATH.

THE ERV SET PRESSURE AND SET VACUUM ARE SET AT THE FACTORY PER PURCHASE ORDER

SPECIFICATIONS. THE SET PRESSURE AND NOMINAL FLOW CAPACITY ARE STAMPED ON THE VAL VE
NAMEPLATE. DO NOT ATTEMPT TO READJUST THE SET PRESSURE. DO NOT CHANGE PRESSURE
RATING BY ADDING ADDITIONAL WEIGHTS TO THE PALLET ASSEMBLY WITHOUT CONSULTING
FACTORY. ADDING MORE WEIGHTS THAN RECOMMENDED WILL RESULT IN AN INCREASE IN SETTING.

DO NOT ATTEMPT TO LIFT PALLET ASSEMBLIES BY HAND. THESE ASSEMBLIES CAN WEIGHT IN EXCESS

OF 400 LBS. AND COULD CAUSE BODILY INJURY WITHOUT THE USE OF AN EXTERNAL LIFTING METHOD.

MODEL 2000A AND 2050A VALVES WILL LIKELY NOT RESEAT AFTER A SIGNIFICANT OVER-PRESSURE

CONDITION. IF THIS IS NOT ACCEPTABLE, IT IS RECOMMENDED TO USE EITHER MODEL 2400A OR 2450A.

EMERGENCY RELIEF VALVES ARE DESIGNED TO PROVIDE FULL RATED CAPACITY AT 100% OVER-

PRESSURE. IF THE VALVE IS TO BE OPERATED AT A REDUCED OVER-PRESSURE, CONSULT FACTORY
FOR ACTUAL FLOW CAPACITY UNDER SPECIFIED CONDITIONS.

DO NOT MIX PALLET ASSEMBLIES FROM DIFFERENT VALVES. FAILURES TO ENSURE THAT THE PALLET

ASSEMBLIES ARE INSTALLED IN THE ORIGINAL AND CORRECT LOCATION CAN CHANGE THE PRESSURE
OR VACUUM RELIEF SETTINGS. THIS CAN CAUSE A TANK FAILURE.

DO NOT LOOSEN HEX NUTS UNTIL ALL SPRING COMPRESSION HAS BEEN RELEASED. SPRING PRE­LOAD IS SUBSTANTIAL AND COULD CAUSE SEVERE PERSONAL INJURY IF FASTENERS WERE REMOVED
WITH THE SPRING COMPRESSED.

DO NOT ATTEMPT TO REMOVE THE VALVE FROM THE TANK OR PROCESS VESSEL WITHOUT FIRST
BLEEDING ALL PRESSURE FROM THE SYSTEM. ALTERNATIVE MEANS OF PRESSURE RELIEF MUST BE
PROVIDED WHEN THE VALVE IS OUT OF SERVICE.

THE VALVE HAS BEEN EXPOSED TO PROCESS VAPORS WHILE IN SERVICE. OBSERVE ALL PLANT
PROCEDURES AND MATERIAL SAFETY DATA SHEETS (MSDS) FOR THE PRODUCTS IN THE SYSTEM
WHEN INSPECTING, ADJUSTING OR SERVICING THE VALVE. TAKE APPROPRIATE SAFETY
PRECAUTIONS REGARDING EYE PROTECTION, RESPIRATION AND SKIN CONTACT.

DO NOT ADD ANY WEIGHT TO THE PALLET ASSEMBLY, CHANGE THE ADJUSTMENT SCREW (CHANGING
SET PRESSURE OR VACUUM), OR CHANGE PALLET STEM WITHOUT FIRST CONSIDERING THE
ALLOWABLE TANK PRESSURE OR WITHOUT MEASURING DESIGN LIFT TO ENSURE THE LIFT IS NOT
RESTRICTED. RESTRICTING VALVE LIFT COULD “CHOKE” THE VALVE AND NOT ALLOW FOR FULL
RATED CAPACITY. CHANGING THE WEIGHT OR ADJUSTMENT OF A SPRING COULD ALSO RESTRICT THE
LIFT OF A VALVE AT A SPECIFIED OVERPRESSURE, REDUCING THE RATED CAPACITY OF THE VALVE.
UNDER THESE CONDITIONS, THE VALVE WILL NOT PROTECT THE TANK FROM RUPTURING DUE TO
CHANGES IN INTERNAL PRESSURE. TANK FAILURE CAN CAUSE MATERIAL DAMAGE AND LOSS AND
RESULT IN SEVERE PERSONAL INJURY OR DEATH.

THE ERV IS EQUIPPED WITH A GROUND STRAP TO PREVENT STATIC ELECTRIC DISCHARGE. THIS
STRAP MUST BE SECURED TO A PROPER GROUND WHILE ALLOWING VALVE OPERATION. IF THIS
STRAP IS IMPROPERLY GROUNDED, STATIC DISCHARGE COULD CAUSE TANK RUPTURE AND RESULT IN
SEVERE INJURY OR DEATH.

4

T

INSPECTION AND INSTALLATION

The ERV is packed and supported to prevent damage or contamination during shipping. It should be similarly
protected during subsequent handling and storage. Before installation inspect the unit visually. If there are
indications of physical damage or internal contamination, the v alve must be disassembled, cleaned and inspected
before installation.

Inspect the valve for any sign of damage that may have occ urred in shipm ent and report this to the carr ier. The seat
protector (rubber strip placed over the valve seat) shall be removed before placing the valve into service.

Handles/Eye Nuts are provided on the upper weight pl ates for handling the pallet assembly. The body has three
lifting eyes that are used to lift and position the body. To avoid damage to the lower flange surface, set the valve on a
soft clean gasket material until it is ready to be installed. It should be stored in a clean environment until it is to be
mounted on the tank.

The 2000A Series Emergency Relief Valve i s a device that must be handled c arefully to ensure seat tightness. The
body is manufactured from thin steel plate material and can be damaged by over-tighten ing the studs or mounting on
a tank nozzle that is not flat. The valve is also equipped with a grounding strap that shou ld be grounded properly to
prevent static electric discharge.

The standard bodies are furnished with flat flanges; the valve shoul d be mounted on a flat faced 150# ANSI or API
650 flange. It is recommended to use a full faced gasket to avoid deflecting the body flange. The connecting flange s
must be flat within 0.015" and clean, free of scratches, corrosion and tool marks.

All valves should be installed using the three body lifting lugs. Mount the valve with the pallet assembly in the
horizontal plane.

1. Begin by inspecting the gasket; make sure that the material is suitable for the service. Gasket dimensions are
listed in Table 2 below:

2. Lubricate all studs and nuts with an appropriate thread lubricant. If stainless steel fasteners are use d, select an
anti-seize lubricant such as moly-disulfide.

3. Align the gasket with the bolt circle.

4. Set the valve body carefully on the nozzle; keep the ga sket between the flanges. Install the studs and tighten
nuts hand tight.

5. Torque all fasteners to half the recommended value (see Table 3) in a s taggered, alternating pattern or follow
appropriate plant maintenance guidelines and standards.

*Note: Torque values are based on a gasket factor m=3.5,
gasket factor y=2000 psi, maximum pressure = 2 psi.

6. Make sure that the flanges are not distorted and that the gasket is evenly compressed.

7. Make up the final torque and check that no further nut rotation occurs.

8. For Model 2 000A and Mode l 2050A, the cov er assembly m ay be inde pendently lifted into positio n by using th e
handles/eye nuts supplied for the weight plates. Align the pallet assembly peripheral guides with the body bore
and carefully lower the cover assembly until it seats against the body.

Table 3: Recommended Torque Values*

able 2: Body Flange Gasket Dimensions

Type Flange

O.D.

(in)

I.D.
(in)

B.C.

(in)

Hole

(in)
FF 16" – 150 # 23.50 15.25 21.25 1.13 16
FF 20" – 150 # 27.50 19.25 25.00 1.25 20
FF 24" – 150 # 32.00 23.25 29.50 1.38 20

FF 20” – API

650

FF 24” – API

650

26.00 19.25 23.50 .75 16

30.00 23.25 27.50 .75 20

Qty.

Size

Qty

Holes

Bolt

(in)

(UNC)

16” 16 1.000 52 104
20” 20 1.125 63 110

150 ANSI

24” 20 1.250 86 148

20” 20 0.625 35 53

5

24” 20 0.625 43 61

API650

Torque (ft-lbs)

Raised

Face

Flange

Face

PREVENTIVE MAINTENANCE

The 2000A Series valves do not require routine l ubrication or adjustments, but should be ch ecked periodically, at least t wice a
year, to confirm that the valve is functioning properly.

Because these valves provide emergenc y protection, they will not normally cycle in service. Inspection of seat ti ghtness should
be done to ensure compliance with local air pollution control requirements as needed. When inspecting the diaphragms,
gaskets and seals should also be checked. Please refer to handli ng instructions listed in the Installation section of this manual.
Always keep records of maintenance performed.

WARNING

If the valve must be removed from the tank for any reas on, make sure that all pressure has been released before the flange
fasteners are loosened. Refer to your company procedures before venting the tank pressure and when handling toxic or
otherwise hazardous materials.

The main valve body, gaskets and all other components 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 while removing the valve and when
repairing it. Take appropriate safety precautions regarding eye protection, respiration & skin contact.

The table below shows the various configurations that make up a 2000A Series valve. Identify the valve, and read the
appropriate section.

Table 4: Configurations

Models Page Guided

Cover
2000A 8 X
2050A 9 X X
2400A 13 X
2450A 14 X X

Each section will describe the disassembly and assembly procedures. Each section references part numbers for that valve only.
Use the diagrams preceding each section.

Inspect the soft goods, the seat, and the flanges to ensure seal tightness. Replace components as necessary.

SOFT GOODS KITS

A soft goods kit consists of the diaphragms and washers, if needed. The following system is used to identify and order kits:

Table 5: 2000 Series – Soft Good Kits Numbering System

Hinged

Cover

Vacuum

Assembly

Prefix Model No. Size

2000 = 2000A

KS

Note: Soft goods for the 2000 and 2000A Model Series are interchangeable.

Example:
KS200016T – A Soft goods kit for a 16"2000 valve made of Fluoropolymer.

2050 = 2050A
2400 = 2400A
2450 = 2450A

16 = 16”

20 = 20”

24 = 24”

6

Soft Good Material

A = Aflas

B = Buna-n

K = FFKM

T = Fluoropolymer

V = FKM

MODEL 2000A DISASSEMBLY & ASSEMBLY

ITEM DESCRIPTION ITEM DESCRIPTION

1 Body
2 Pallet
3 Retainer Plate
4 Flat Washer, 3/4", SS
5 Ground Cable
6 Sleeve

2000A Disassembly

1. Read “Warning” sections on page 5. Remove the valve from the tank.

2. Using the eye nut [12], or the edges of the pallet, lift vertically. Set the cover on a short length of pipe
(minimum 6” high). This will elevate the retainer plate peripheral guides above the table so they
aren’t bent or damaged.

3. Place the assembly with the ¾” hex bolt in a vise, or use a wrench to hold the center bolt from the
bottom side. Loosen the hex nuts and remove. Lift the weight plate [11], pallet [2], and diaphragms
[9].

2000A Assembly

1. Prior to final assembly, verify that the body seat area is free of corrosion, damage or product build-up.
The seat should be carefully cleaned, if necessary.

NOTE: If the seat is damaged it must be lapped using a perfectly flat ground metal disc. Wipe

seating surface clean before proceeding. Soft goods should normally be replaced whenever
valve maintenance is performed.

2. Reverse the steps of Disassembly, starting with the retainer and cover. If a diaphragm is an
elastomer, place it between the fluoropolymer diaphragm and the retainer plate. See Figure 3b.

NOTE: When replacing the ground cable, surface corrosion must be completely cleaned to allow

cable to ground pallet to tank nozzle.

3. The valve should be tested on a pressure test stand to verify the settings and evaluate seat tightness
follow instructions on page 19. Mount valve on tank; see Installation on page 6.

7 Hex Nut, 3/4"-10 UNC
8 W asher, 3/4", PTF E

9 Diaphragm
10 Hex Bolt, 3/4"-10 UNC
11 Weight Plate(s)*
12 Eye Nut*

* Not used on valves with low settings

7

MODEL 2050A DISASSEMBLY & ASSEMBLY

ITEM DESCRIPTION ITEM DESCRIPTION

1 Body 17 Stem Guide
2 Pallet – Pressure 18 Seat – Vacuum
3 Retainer Plate – Pressure 19 Hex Bolt, 3/8"-16 UNC
4 Flat Washer, 3/8", SS 20 Flat Washer, 3/8", SS
5 Ground Cable 21 Hex Nut, 3/8"-16 UNC
6 Sleeve 22 Lock Washer, 3/8"
7 Hex Nut, 3/8"-16 UNC 23 Pallet – Vacuum
8 N/A 24 Retainer Plate – Vacuum

9 Flat Washer, 3/8", PTFE 25 Crown Nut, 3/8"-16 UNC
10 Diaphragm – Pressure 26 Screen
11 Diaphragm – Vacuum 27 Weatherhood Post
12 Spacer 28 Water Dam*
13 Weatherhood 29 Weight Plate*
14 Stem – Vacuum 30 Handle*
15 Hex Nut, 1/2"-13 UNC 31 Spring
16 Spring Button

* Not used on valves with low settings.

2050A Disassembly

1. Read “Warning” sections on page 5. Remove the valve from the tank.

2. Lift pressure/vacuum pallet [2] assembly from body [1].

3. Using the handles [30] on the weight plate [29], or the edges of the pallet, lift vertically. Set the cover
on three evenly spaced support blocks (Figure 6). This will elevate the retainer plate peripheral
guides above the table so they aren’t bent or damaged.

4. Remove nut s [25], lift weatherhood [13], bird screen [26] and set aside. Remove the nut holding the
ground cable [5], and remove the cable.

5. Record “A” dimension (Figure 7). Place a short length of pipe (minimum 6” high) beneath the
vacuum pallet [23] to prevent it from falling. Back the top nut [15] completely off the stem. Compress
the spring using the spring button [16] and grasp the stem (Figure 8). Caution: Remove the second

8

nut from the stem. Slowly raise the spring
button to release the spring compression. The
spring force will be in 5 – 30 lb range, depending
on vacuum setting.

6. Using weight plate handles, if included, lift pressure
pallet [2] with attached assembly and remove
vacuum pallet-stem [23, 14] assembly from the
bottom.

7. Remove the nuts on the weatherhood posts holding
the stem guide [17]. Note: For low pressure
settings, a weight plate is added on the stem guide
[17].

8. Lift the spacers [12]. Remove the nuts above the
water dam [28]. Note: Water dam is only used if
weight plate is mounted directly on pressure pallet
[2].

9. Remove the weatherhood posts [27] by loosening
the nuts beneath the pallet.

10. Carefully lift the weight plate [29] vertically.

Caution: This may require a crane due to the
weight. (See Warning on page 5.)

Figure 6 : Pallet Support (2050A)

11. Turn pallet assembly upside down (Figure 9).

12. Remove remaining bolts, nuts, and washers [7, 9,
19, 20, 21] to separate the vacuum seat.

13. Lift the retainer plate [3] and diaphragms [10] from
the pressure pallet.

2050A Assembly
Rebuild the valve reversing the disassembly steps.

1. Begin by placing the pallet [2] upside down on
support blocks evenly spaced or on a pipe.

2. Wipe clean “air cushion” groove (seat area) in
pallet.

3. Center diaphragms [10] (qty 2) on pallet. See

Figure 3 for orientation of diaphragms, if elastomer
is used.

4. Place retainer plate [3], align with pallet hole
pattern.

Figure 7 : Vacuum Spring Compression

Figure 8 : Loosening Nuts for Spring

9

Figure 9: Exploded View of Pallet Assembly (Upside Down)

5. Apply PTFE sealant tape around the inside hole pattern of
the vacuum seat [18] (Figure 10). Tape should be at least
1/16” thick. Note: Other sealants (such as Silicone) can

replace the fluoropolymer tape if compatible with tank
products.

6. Position the vacuum seat [18] as shown from beneath the
pallet.

7. Align vacuum seat with pallet and insert 4 bolts (at 90
degrees from each other) from the top using fasteners
shown in Figure 9 [7, 19, 20, 21].

Figure 10: Sealant tape on Vacuum Seat

8. Insert four more bolts, leaving four holes, at 90 degrees from
each other, open. The weatherhood posts are installed in
these holes.

9. Turn pallet assembly right side up, and place on support blocks again.

10. Run 3/8” hex nut up 1 1/2” from end on all thread and insert weatherhood posts [27] in remaining
holes. A Fluoropolymer washer, flat washer and nut are installed from the bottom. Allow
approximately 2 threads past the nut to be free. The four weatherhood posts should all extend
approximately 11.13” above the pallet.

11. Lower the weight plate [29] (if needed for setting).

12. Use a sealant tape around the inner edge of the weight plate. Note: Other sealants (such as Silicone)
can replace the Fluoropolymer tape if compatible with tank products.

13. Insert the waterdam [28] using the weatherhood posts [27] as a guide. Use sealant tape on bottom
side, outside of its hole pattern. Tighten nuts. Note: Do not over-tighten. It is suggested to first
hand tighten the nuts, torque 15 ft-lbs in an alternating criss-cross pattern.

14. Insert the spacers [12], and the stem guide [17]. Tighten nut to retain to pallet assembly.

15. If pallet assembly is high enough from the table, insert vacuum pallet-stem [23, 24, 14] assembly
from beneath. Place a short length of pipe (minimum 6” high) beneath the vacuum assembly to hold
it in place until the spring is installed.

10

16. Place spring [31] over the stem [14]. Use the spring button [16] to compress the spring [31]. Insert
nuts [15] and tighten. Compress the spring using the lower nut [15] until the “A” dimension is
achieved.

WARNING

Failure to properly set a spring loaded valve can result in improper valve operation and can cause tank damage.

17. Install the ground cable [5]. Use a hex nut to hold in place. Add the screen [26]. Note: Ground cable
will run through the screen.

18. Run a nut down each weatherhood post [27] approximately 0.5” to allow thread engagement when
the weatherhood [13] and crown nuts [21] are installed.

19. Place weatherhood [13] on posts, and tighten with crown nuts [25].

20. Prior to final assembly, verify that the body seat area is free of corrosion, damage or product build-up.
The pallet seat should be cleaned carefully, if necessary. Place pallet assembly on top of body.

21. The valve should be tested on a pressure test stand to verify the settings and evaluate seat tightness
follow instructions on page 19. Mount valve on tank; see Installation on page 6.

11

MODEL 2400A DISASSEMBLY & ASSEMBLY

ITEM DESCRIPTION ITEM DESCRIPTION

1 Body 10 Diaphragm
2 Pallet 11 Washer, 3/8", PTFE
3 Retainer Plate 12 Hex Nut, 3/4"-10 UNC
4 Hinge Arm 13 Lock Washer, 3/4"
5 Hinge Pin 14 Hex Bolt, 3/4"-10 UNC
6 Cotter Pin 15 Hex Bolt, 3/8"-16 UNC
7 Hex Nut, 3/8"-16 UNC 16 Weight Plate*
8 Lock Washer, 3/8" 17 Eye Nut*
9 Washer, 3/4", PTFE

* Not used on valves with low settings

2400A Disassembly

1. Read “Warning” sections on pages 4 and 6. Remove the valve from the tank.

2. Remove the cotter pin [6], from the hinge pin [5]. Pull the hinge pin through the body brackets.
Using the eye nut [17], or the edges of the pallet, lift the cover vertically. Set the cover on a short
length of pipe (minimum 6” high). This will elevate the retainer plate peripheral guides above the
table so they aren’t bent or damaged.

3. Place the assembly with the ¾” hex bolt in a vise, or use a wrench to hold the center bolt from the
bottom side. Loosen the hex nuts and remove. Lift the weight plate [16], pallet [2], and
diaphragms [10].

2400A Assembly

1. Prior to final assembly, verify that the body seat area is free of corrosion, damage or product build-up.
The pallet seat should be cleaned carefully, if necessary.

NOTE: If the seat is damaged it must be lapped using a perfectly flat ground metal disc and fine

grit emery cloth attached to the disc. Wipe seating surface clean before proceeding. Soft
goods should normally be replaced whenever valve maintenance is performed.

2. Reverse the steps of Disassembly, starting with the retainer and cover. If a diaphragm is an
elastomer, place it between the FEP diaphragm and the retainer plate. See Figure 3b.

3. Replace the cotter pin [6] if needed.

4. The valve should be tested on a pressure test stand to verify the settings and evaluate seat tightness
follow instructions on page 19. Mount valve on tank; see Installation on page 6.

12

MODEL 2450A DISASSEMBLY & ASSEMBLY

ITEM DESCRIPTION ITEM DESCRIPTION

1 Body 17 Stem Guide
2 Pallet – Pressure 18 Seat – Vacuum
3 Retainer Plate – Pressure 19 Hex Bolt, 3/8-16 UNC
4 Hinge Arm 20 Flat Washer, 3/8", SS
5 Hinge Pin 21 Hex Nut, 3/8-16 UNC
6 Cotter Pin 22 Lock Washer, 3/8"
7 Hex Nut, 3/8-16 UNC 23 Pallet – Vacuum
8 Lock Washer 24 Retainer Plate – Vacuum

9 Washer, 3/8", PTFE 25 Crown Nuts, 3/8- 16
10 Diaphragm – Pressure 26 Screen
11 Diaphragm – Vacuum 27 Weatherhood Post
12 Spacer 28 Water Dam*
13 Weatherhood 29 Weight Plate*
14 Stem – Vacuum 30 Handle*
15 Hex Nut, 1/2-13 UNC 31 Spring
16 Spring Button 32 Hex Bolt, 3/8-16 UNC

* Not used on valves with low settings.

2450 DISASSEMBLY

1. Read “Warning” sections on pages 4 and 6. Remove the valve from the tank.

2. Remove hinge pin [5], and cotter pin [6] from the hinge arm and brackets.

3. Lift pressure/vacuum pallet [2] with attached assembly from body [1].

4. Using the handles [30] on the weight plate [29], or the edges of the pallet [2], lift vertically. Set the
cover on a short length of pipe (minimum 6” high) (Figure 13). This will elevate the retainer plate
peripheral guides above the table so they aren’t bent or damaged.

5. Remove crown nuts [25], lift weatherhood [13], bird screen [26] and set aside.

6. Record “A” dimension (Figure 14). Place a short length of pipe (minimum 6” high) beneath the
vacuum pallet [23] to prevent it from falling. Back the top nut [15] completely off the stem. Compress
the spring using the spring button [16] and grasp the stem (Figure 15). Caution: Remove the

13

second nut from the stem. Slowly raise the
spring button to release the spring
compression. The spring force will be in 5 – 30
lb range, depending on vacuum setting.

7. Using weight plate handles, if included, lift pallet [2]
with attached assembly and remove vacuum pallet­stem [23, 14] assembly from the bottom.

8. Remove the nuts on the weatherhood posts
holding the stem guide [17]. Note: For low
pressure settings, a weight plate is added on the
stem guide [17].

9. Lift the spacers [12]. Remove the nuts above the
water dam [28]. Note: Water dam is only used if
weight plate is mounted directly on pressure pallet
[2].

10. Remove the weatherhood posts [27] by loosening
the nuts beneath the pallet.

11. Remove the hinge arm [4] by loosening the
fasteners [7, 8].

12. Carefully lift the weight plate [29] vertically.

Caution: This may require a crane due to the
weight. (See Warning on page 4.)

13. Turn pallet assembly upside down (Figure 16).

14. Remove remaining bolts, nuts, and washers [7, 9,
19, 20, 21] to separate the vacuum seat.

Figure 13: Pallet Support (2450A)

Figure 14 : Vacuum Spring Compression

15. Lift the retainer plate [3] and diaphragms [10] from
the pressure pallet.

2450 Assembly
Rebuild the valve reversing the disassembly steps.

1. Begin by placing the pallet [2] upside down on
support blocks evenly spaced or on a pipe.

2. Wipe clean “air cushion” groove (seat area) in pallet.

3. Center diaphragms [10] (qty 2) on pallet. See

Figure 3 for orientation of diaphragms, if elastomer
is used.

14

Figure 15: Loosening Nuts for Spring

FluoropolymerWasher

FluoropolymerWasher

Figure 16: Exploded View of Pallet Assembly (Upside Down)

4. Place retainer plate [3], align with pallet hole pattern.

5. Apply PTFE sealant tape around the inside hole pattern
of the vacuum seat [18] (Figure 17). Tape should be at
least 1/16” thick. Note: Other sealants (such as Silicone)
can replace the Fluoropolymer tape if compatible with
tank products.

6. Position the vacuum seat [18] as shown from beneath
the pallet.

7. Align vacuum seat with pallet and insert 4 bolts (at 90
degrees from each other) from the top using fasteners
shown in Figure 16 [7, 19, 20, 21].

Figure 17 : Sealant tape on Vacuum Seat

8. Insert four more bolts, leaving four holes, at 90 degrees
from each other, open. The weatherhood posts are
installed in these holes.

9. Turn pallet assembly right side up, and place on support blocks again.

10. Run 3/8” hex nut up 1 1/2” from end on all thread and insert weatherhood posts [27] in remaining
holes. A Fluoropolymer washer, flat washer and nut are installed from the bottom. Allow
approximately 2 threads pass the nut to be free. The four weatherhood posts should all extend
approximately 11.13” above the pallet.

11. Lower the weight plate [29] (if needed for setting).

12. Set the hinge [4] above the weight plate, and insert the bolts [7, 8, 32]. Tighten.

13. Use a sealant tape around the inner edge of the weight plate. Note: Other sealants (such as Silicone)
can replace the Fluoropolymer tape if compatible with tank products.

14. Insert the waterdam [28] using the weatherhood posts [27] as a guide. Use sealant tape on bottom
side, outside of its hole pattern. Tighten nuts. Note: Do not over-tighten. It is suggested to first

hand tighten the nuts, torque 12 to 15 ft-lbs in an alternating criss-cross pattern.

15. Insert the spacers, and the stem guide [17]. Tighten nut to retain to pallet assembly.

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16. If pallet assembly is high enough from the table, insert vacuum pallet-stem [23, 24, 14] assembly
from beneath. Place a short length of pipe (minimum 6” high) beneath the vacuum assembly to hold
it in place until the spring is installed.

17. Place spring [31] over the stem [14]. Use the spring button [16] to compress the spring [31]. Insert
nuts [15] and tighten. Compress the spring using the lower nut [15] until the “A” dimension is
achieved.

WARNING

Failure to properly set a spring loaded valve can result in improper valve operation and can cause a tank failure.

18. Install the ground cable [5]. Use a hex nut to hold in place. Add the screen [26]. Note: Ground cable
will run through the screen.

19. Run a nut down each weatherhood post [27] approximately 0.5” to allow thread engagement when
the weatherhood [13] and crown nuts [21] are installed.

20. Place weatherhood [13] on posts, and tighten with crown nuts [25].

21. Prior to final assembly, verify that the body seat area is free of corrosion, damage or product build-up.
The pallet seat should be cleaned carefully, if necessary. Place pallet assembly on top of body.

22. Slide hinge pin [5] through the body’s ears and the hinge. Secure with cotter pins [6].

23. The valve should be tested on a pressure test stand to verify the settings and evaluate seat tightness
follow instructions on page 19. Mount valve on tank; see Installation on page 6.

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TESTING AND SETTING PROCEDURE

SETUP
After final assembly, mount the valve on a tank vent test stand or on a blind flange with instrument tap. Use appropriate gaskets
and bolt using at least half of the available flange holes. Tighten fasteners alternately in a crossing pattern to ensure that the
ERV body is not distorted or warped. If clamping is used, reduce hydraulic or pneumatic pressure to minimum.

TESTING FOR SET PRESSURE AND SEAT LEAKAGE
Slowly increase the vessel pressure by flowing at 20 SCFH through a flowmeter. Record peak pressure attained, this pressure
is the seat leakage pressure (as recorded on the original test report supplied by Groth Corporation at the time of order). Next
increase the flow to the test tank (increasing the pressure) until an increase in flow to the test tank does not cause an increase in
pressure in the tank. This pressure is the set pressure of the valve. At this pressure the pallet assembly will typically appear to
float above seat. Conduct two additional seat leakage and set pressure tests.

TESTING FOR SET VACUUM AND SEAT LEAKAGE
Conduct the same tests as previously described to determine the set vacuum and seat leakage.

Complete a test report indicating the actual pallet assembly weight and the peak pressure / vacuum achieved at the specified
test flow rate. Maintain a copy of the test report.

TROUBLESHOOTING
If there is excessive leakage, inspect the following:

- Inspect seat on body (Be aware of nicks, scratches and flatness.)

- Inspect diaphragm

- Inspect flatness of pallet

- Verify weight of assembly (doesn’t affect vacuum operation)

In order to maintain a tight seal, components have to be clean and have a smooth surface at the contact areas.

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MODEL INFORMATION

The nameplate on the Groth Series 2000A Emergency Relief Valves contains the model number, serial
number, set pressure and flow capacity. The model number contains additional information about
materials of construction and options. The following chart will assist in relating the model number to the
specifications of your pilot operated valve:

PRODUCT LIMITED WARRANTY

Only Groth’s Product Limited Warranty terms apply to purchase orders accepted by Groth Corporation.

A. Seller warrants that products that are manufactured by Seller are manufactured i n accordance with publi shed 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,
determines to be defective in material and/or workmanship. T he foregoing shall co nstitute the sole r emedy for an y brea ch 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 d amages for loss of time,
inconvenience, or loss of use of any such product.

C.The original Manufacturer shall be solely responsibl e for the design, development, supply, production, and performance of

its products hereunder, and the protection of its trade name or names, if any. It assu mes no responsibility, for products
modified or changed by its agent or customer, or any other third party. Any such modifications or c hanges to products sold
by Seller hereunder shall make the product limited warranty null and void.

D.Groth assumes no responsibility for products modified or changed by Customer or any other third party. Any such

modifications or changes to products sold by Groth hereunder sh all make the product limited warranty null and vo id. Groth
shall be under no obligation to manufacture, sell or supply, or to continue to manufacture, sell, or supply any of the pro ducts.

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