Baker Hughes Consolidated 2478 Series User manual

Consolidated™
2478 Series
Pressure Relief Valves
Instruction Manual (Rev. C)
Baker Hughes Data Classification : Public

ii | Baker Hughes © 2020 Baker Hughes Company. All rights reserved.

Consolidated 2478 Series Pressure Relief Valve Manual | 1
© 2020 Baker Hughes Company. All rights reserved.
THESE INSTRUCTIONS PROVIDE THE CUSTOMER/OPERATOR WITH IMPORTANT
PROJECT-SPECIFIC REFERENCE INFORMATION IN ADDITION TO THE CUSTOMER/
OPERATOR’S NORMAL OPERATION AND MAINTENANCE PROCEDURES. SINCE
OPERATION AND MAINTENANCE PHILOSOPHIES VARY, BAKER HUGHES (AND
ITS SUBSIDIARIES AND AFFILIATES) DOES NOT ATTEMPT TO DICTATE SPECIFIC
PROCEDURES, BUT TO PROVIDE BASIC LIMITATIONS AND REQUIREMENTS
CREATED BY THE TYPE OF EQUIPMENT PROVIDED.
THESE INSTRUCTIONS ASSUME THAT OPERATORS ALREADY HAVE A GENERAL
UNDERSTANDING OF THE REQUIREMENTS FOR SAFE OPERATION OF MECHANICAL
AND ELECTRICAL EQUIPMENT IN POTENTIALLY HAZARDOUS ENVIRONMENTS.
THEREFORE, THESE INSTRUCTIONS SHOULD BE INTERPRETED AND APPLIED
IN CONJUNCTION WITH THE SAFETY RULES AND REGULATIONS APPLICABLE AT
THE SITE AND THE PARTICULAR REQUIREMENTS FOR OPERATION OF OTHER
EQUIPMENT AT THE SITE.
THESE INSTRUCTIONS DO NOT PURPORT TO COVER ALL DETAILS OR VARIATIONS
IN EQUIPMENT NOR TO PROVIDE FOR EVERY POSSIBLE CONTINGENCY TO BE MET
IN CONNECTION WITH INSTALLATION, OPERATION OR MAINTENANCE. SHOULD
FURTHER INFORMATION BE DESIRED OR SHOULD PARTICULAR PROBLEMS ARISE
WHICH ARE NOT COVERED SUFFICIENTLY FOR THE CUSTOMER/OPERATOR'S
PURPOSES THE MATTER SHOULD BE REFERRED TO BAKER HUGHES.
THE RIGHTS, OBLIGATIONS AND LIABILITIES OF BAKER HUGHES AND THE
CUSTOMER/OPERATOR ARE STRICTLY LIMITED TO THOSE EXPRESSLY PROVIDED
IN THE CONTRACT RELATING TO THE SUPPLY OF THE EQUIPMENT. NO ADDITIONAL
REPRESENTATIONS OR WARRANTIES BY BAKER HUGHES REGARDING THE
EQUIPMENT OR ITS USE ARE GIVEN OR IMPLIED BY THE ISSUE OF THESE
INSTRUCTIONS.
THESE INSTRUCTIONS ARE FURNISHED TO THE CUSTOMER/OPERATOR SOLELY
TO ASSIST IN THE INSTALLATION, TESTING, OPERATION, AND/OR MAINTENANCE
OF THE EQUIPMENT DESCRIBED. THIS DOCUMENT SHALL NOT BE REPRODUCED
IN WHOLE OR IN PART WITHOUT THE WRITTEN APPROVAL OF BAKER HUGHES.

2 | Baker Hughes © 2020 Baker Hughes Company. All rights reserved.
Conversion Table
USCS Unit Conversion Factor Metric Unit
in. 25.4 mm
lb. 0.4535924 kg
in26.4516 cm2
ft3/min 0.02831685 m3/min
gal/min 3.785412 L/min
lb/hr 0.4535924 kg/hr
psig 0.06894757 barg
ft lb 1.3558181 Nm
°F 5/9 (°F-32) °C
Note: Multiply USCS value with Conversion Factor to get Metric value.
All the United States Customary System (USCS)
values in the Manual are converted to Metric values using
the following conversion factors:
NOTICE!
For valve congurations not listed in this
manual, please contact your local Green
Tag™ Center (GTC) for assistance.

Consolidated 2478 Series Pressure Relief Valve Manual | 3
© 2020 Baker Hughes Company. All rights reserved.
Table of Contents
I. Product Safety Sign and Label System ................................................................................. 4
II. Safety Precautions................................................................................................................. 5
III. Safety Notice ......................................................................................................................... 6
IV. Warranty Information ............................................................................................................. 7
V. Valve Terminology.................................................................................................................. 7
VI. Handling and Storage ............................................................................................................ 9
VII. Pre-Installation and Installation Instructions .......................................................................... 9
VIII. Introduction ............................................................................................................................ 9
IX. Consolidated 2478 Series Relief Valve................................................................................ 10
X. Operating Principle ...............................................................................................................11
XI. Disassembly of 2478 Series Relief Valve .............................................................................11
XII. Inspection and Part Replacement........................................................................................ 12
XIII. Reassembly of 2478 Series Relief Valve............................................................................. 13
XIV. Setting and Testing .............................................................................................................. 14
XV. Trouble Shooting ................................................................................................................. 14
XVI. Replacement Parts Planning ............................................................................................... 15
A. Basic Guidelines ............................................................................................................ 15
B. Identication and Ordering Essentials ........................................................................... 15
XVII. Genuine Consolidated Parts................................................................................................ 15
XVIII. Recommended Spare Parts ................................................................................................ 16
XIX. Manufacturer’s Field Service & Repair Program ................................................................ 17
A. Field Service .................................................................................................................. 17
B. Factory Repair Facilities ................................................................................................ 17
C. Relief Valve Maintenance Training................................................................................. 17

4 | Baker Hughes © 2020 Baker Hughes Company. All rights reserved.
DANGER — Immediate hazards
which WILL result in severe
personal injury or death.
WARNING — Hazards or unsafe
practices which COULD result
in severe personal injury or
death.
CAUTION — Hazards or unsafe
practices which COULD result
in minor personal injury.
ATTENTION — Hazards or
unsafe practices which COULD
result in product or property
damage.
1
3
4
If and when required, appropriate safety labels have been included in
the rectangular margin blocks throughout this manual. Safety labels are
vertically oriented rectangles as shown in the representative examples
(below), consisting of three panels encircled by a narrow border. The
panels can contain four messages which communicate:
• The level of hazard seriousness
• The nature of the hazard
• The consequence of human, or product, interaction with the hazard.
• The instructions, if necessary, on how to avoid the hazard.
The top panel of the format contains a signal word (DANGER, WARNING,
CAUTION or ATTENTION) which communicates the level of hazard
seriousness.
The center panel contains a pictorial which communicates the nature of
the hazard, and the possible consequence of human or product interaction
with the hazard. In some instances of human hazards the pictorial may,
instead, depict what preventive measures to take, such as wearing
protective equipment.
The bottom panel may contain an instruction message on how to avoid
the hazard. In the case of human hazard, this message may also contain
a more precise denition of the hazard, and the consequences of human
interaction with the hazard, than can be communicated solely by the
pictorial.
I. Product Safety Sign and Label System
Do not remove bolts
if pressure in line, as
this will result in severe
personal injury or death.
Know all valve
exhaust/leakage points
to avoid possible
severe personal injury
or death.
Wear necessary
protective equipment to
prevent possible injury
Handle valve carefully.
Do not drop or strike.
2
1234

Consolidated 2478 Series Pressure Relief Valve Manual | 5
© 2020 Baker Hughes Company. All rights reserved.
Lower pressure and stand
clear of discharge when
working on valve to avoid
severe personal injury or
death.
Know all valve exhaust/
leakage points to
avoid possible severe
personal injury or death.
II. Safety Precautions
Follow all plant safety regulations, but be sure to observe the following:
• Always lower the working pressure before making any valve adjustment. When
making ring adjustments, always gag the valve before making the adjustment. This
will avoid possible personal injury.
• Do not stand in front of the discharge side of a safety valve when testing or
operating.
• Hearing and eye protection should be used when testing or operating a valve.
• Wear protective clothing. Hot water can burn and superheated steam is not visible.
• When removing the safety valve during disassembly, stand clear and/or wear
protective clothing to prevent exposure to splatter, or any corrosive process medium,
which may have been trapped inside the valve. Ensure the valve is isolated from
system pressure before the valve is removed.
• Exercise care when examining a safety valve for leakage.
• Prior to each actuation, assure that no personnel are near the valve. Steam
escaping from the valve during actuation can possibly cause personal injury.
• When popping a safety valve for the rst time, or after refurbishment, always be
prepared to actuate the valve with the lever while standing in a safe place away from
the valve. This may be done by xing a rope to the lever for actuating the valve from
a distance.
• Striking a valve which is under pressure can cause premature actuation. Never
tamper with the valve when system pressure is near the valve set pressure.
• Before performing any machining on valve parts, consult Baker Hughes or its
authorized representative. Deviation from critical dimensions can adversely a󰀨ect
valve performance.

6 | Baker Hughes © 2020 Baker Hughes Company. All rights reserved.
Proper installation and start-up is essential to the safe and reliable operation of
all valve products. The relevant procedures recommended by Baker Hughes, and
described in these instructions, are e󰀨ective methods of performing the required
tasks.
It is important to note that these instructions contain various “safety messages”
which should be carefully read in order to minimize the risk of personal injury,
or the possibility that improper procedures will be followed which may damage
the involved Baker Hughes product, or render it unsafe. It is also important to
understand that these “safety messages” are not exhaustive. Baker Hughes can
not possibly know, evaluate, and advise any customer of all of the conceivable
ways in which tasks might be performed, or of the possible hazardous
consequences of each way. Consequently, Baker Hughes has not undertaken
any such broad evaluation and, thus, anyone who uses a procedure and/or tool,
which is not recommended by Baker Hughes, or deviates from Baker Hughes
recommendations, must be thoroughly satised that neither personal safety, nor
valve safety, will be jeopardized by the method and/or tools selected. Contact your
local Green Tag Center (GTC) if there are any questions relative to tools/methods.
The installation and start-up of valves and/or valve products may involve proximity
to uids at extremely high pressure and/or temperature. Consequently, every
precaution should be taken to prevent injury to personnel during the performance
of any procedure. These precautions should consist of, but are not limited to, ear
drum protection, eye protection, and the use of protective clothing, (i.e., gloves,
etc.) when personnel are in, or around, a valve work area. Due to the various
circumstances and conditions in which these operations may be performed on
Baker Hughes products, and the possible hazardous consequences of each way,
Baker Hughes can not possibly evaluate all conditions that might injure personnel
or equipment. Nevertheless, Baker Hughes does o󰀨er certain Safety Precautions,
listed in Section II, for customer information only.
It is the responsibility of the purchaser or user of Baker Hughes valves/equipment
to adequately train all personnel who will be working with the involved valves/
equipment. For more information on training schedules, please contact your
local Green Tag Center (GTC). Further, prior to working with the involved valves/
equipment, personnel who are to perform such work should become thoroughly
familiar with the contents of these instructions.
III. Safety Notice
Wear necessary
protective equipment to
prevent possible injury

Consolidated 2478 Series Pressure Relief Valve Manual | 7
© 2020 Baker Hughes Company. All rights reserved.
• Back Pressure
Back pressure is the static pressure existing at the
outlet of a safety valve device due to pressure in the
discharge system.
• Blowdown
Blowdown is the di󰀨erence between actual popping
pressure of a safety valve and actual reseating
pressure expressed as a percentage of set pressure,
or in pressure units.
• Bore Area
Bore area is the minimum cross-sectional area of the
seat bushing.
• Bore Diameter
Bore diameter is the minimum diameter of the seat
bushing.
• Built-Up Back Pressure
Pressure existing at the outlet of a safety valve while it
is open and owing through a discharge system.
• Chatter
Chatter is abnormal, rapid reciprocating motion of the
moveable parts of a safety valve, in which the disc
contacts the seat.
• Closing Pressure
Closing pressure is the value of decreasing inlet static
pressure at which the valve disc re-establishes contact
with the seat, or at which lift becomes zero.
• Disc
A disc is the pressure containing moveable member of
a safety valve which a󰀨ects closure.
• Inlet Size
Inlet size is the nominal pipe size of the inlet of a
safety valve, unless otherwise designated.
• Leak Test Pressure
Leak test pressure is the specied inlet static pressure
at which a quantitative seat leakage test is performed
in accordance with a standard procedure.
• Lift
Lift is the actual travel of the disc away from closed
position when a valve is relieving.
• Lifting Device
A lifting device is a device for manually opening a
safety valve, by the application of external force
to lessen the spring loading which holds the valve
closed.
• Seat Bushing
A seat bushing is the pressure containing element
which constitutes the inlet ow passage and includes
the xed portion of the seat closure.
• Outlet Size
Outlet size is the nominal pipe size of the outlet
passage of a safety valve, unless otherwise
designated.
V. Valve Terminology (Paraphrased from ASME’s PTC 25)
IV. Warranty Information
Warranty Statement: Baker Hughes warrants that its
products and work will meet all applicable specications
and other specic product and work requirements
(including those of performance), if any, and will be
free from defects in material and workmanship. Refer
to Baker Hughes’s Standard Terms of Sale, or specic
contract for complete details on warranty and limitation
of remedy and liability.
Defective and nonconforming items must be held
for Baker Hughes’s inspection and returned to the
manufacturer upon request.
Incorrect Selection or Misapplication of Products:
Baker Hughes cannot be responsible for customer’s
incorrect selection or misapplication of our products.
Unauthorized Repair Work: Baker Hughes has not
authorized any non-Baker Hughes a󰀩liated repair
companies, contractors or individuals to perform
warranty repair service on new products or eld repaired
products of its manufacture. Therefore, customers
contracting such repair services from unauthorized
sources must do so at their own risk.
Unauthorized Removal of Seals: All new valves and
valves repaired in the eld by Baker Hughes Field
Service are sealed to assure the customer of our
guarantee against defective workmanship. Unauthorized
removal and/or breakage of this seal will negate our
warranty.

8 | Baker Hughes © 2020 Baker Hughes Company. All rights reserved.
V. Valve Terminology (Cont.)
• Overpressure
Overpressure is a pressure increase over the set
pressure of a safety valve, usually expressed as a
percentage of set pressure.
• Popping Pressure
Popping pressure is the value of increasing inlet
static pressure at which the disc moves in the
opening direction at a faster rate as compared
with corresponding movement at higher or lower
pressures. It applies only to safety or safety relief
valves on compressible uid service.
• Pressure Containing Member
A pressure containing member of a safety valve is a
part which is in actual contact with the pressure media
in the protected vessel.
• Pressure Retaining Member
A pressure retaining member of a safety valve is a part
which is stressed due to its function in holding one or
more pressure containing members in position.
• Rated Lift
Rated lift is the design lift at which a valve attains its
rated relieving capacity.
• Safety Valve
A safety valve is a pressure relief valve actuated
by inlet static pressure and characterized by rapid
opening or pop action.
• Set Pressure
Set pressure is the value of increasing inlet static
pressure at which a safety valve displays the
operational characteristics as dened under “Popping
Pressure.” It is one value of pressure stamped on the
safety valve.
• Seat
A seat is the pressure containing contact between the
xed and moving portions of the pressure containing
elements of a valve.
• Seat Diameter
Seat diameter is the smallest diameter of contact
between the xed and moving members of the
pressure containing elements of a valve.
• Seat Tightness Pressure
Seat tightness pressure is the specic inlet static
pressure at which a quantitative seat leakage test is
performed in accordance with a standard procedure.
• Simmer
Simmer is the audible or visible escape of uid
between the seat and disc at an inlet static pressure
below the popping pressure and at no measurable
capacity. It applies to safety valves on compressible
uid service.
• Warn
See “Simmer” (denition above).

Consolidated 2478 Series Pressure Relief Valve Manual | 9
© 2020 Baker Hughes Company. All rights reserved.
VIII. Introduction
A relief valve is a key safety device that protects against
catastrophic pressure vessel failure. However, if it is not
properly installed, maintained, operated and repaired,
the pressure vessel is like a potential bomb.
For example: A 30-gallon (114 Ltr.) hot water tank at 90
psig (6.21 barg) has 3,138,400 ft-Ib (4,25,5099 N-m) of
energy to ash its water into steam at 330°F (166°C)
if liberated by rupture. Energy of a pound of three
common explosives is:
Black powder 906 ft-Ib (1228 N-m)
Smokeless powder 1260 ft-Ib (1708 N-m)
Nitroglycerin 2,000,000 ft-Ib (2,711,636 N-m)
On this basis, the 30-gallon (114 Ltr.) tank is equivalent
to about 1.5 lb (0.68 kg) of nitroglycerin. Catastrophes,
of course, are not the only loss exposure from improper
safety-valve operation. Overpressure can rupture tubing
and blow out packing. Improperly maintained safety
valves, at times, may relieve at too low a pressure or may
leak, so the boiler never reaches the desired pressure or
full e󰀩ciency. The result of these problems is unscheduled
downtime. In summary, proper installation, maintenance
and repair is as important as buying of a reliable valve.
This manual therefore provides instructions for installation,
maintenance and repair of Consolidated Bronze Safety
Valves.
1. The valves should be stored in a dry environment to
protect them from the weather.
2. The valves should never be subjected to sharp
impact. This would be most likely to occur by
bumping or dropping during loading or unloading
from a truck or while moving with a power conveyor,
such as a fork lift truck.
3. Meticulous care should be exercised to prevent
dirt and other foreign materials from entering the
inlet and outlet ports during storage as well as in
installation.
The 2478 Series relief valve is provided with a male NPT
inlet connection and a standard hexagon surface for
easy wrench installation. Exhaust outlets are female NPT
connections suitable for standard size pipe ttings. The
2478 Series relief valve must be connected in an upright
vertical position on equal size ttings. Furthermore, in
no case should the discharge pipe connected to the
valve be of a smaller size than the valve outlet. No stop
valve or other obstruction should be placed between the
equipment and the relief valve.
Thoroughly clean the inlet of the valve before installation
and be sure that no pipe thread compound gets into the
bore of the valve during installation.
During installation do not use excessive wrenching force
that may distort the hex on the valve base. The valve
must not be tightened by means of a pipe screwed into
the outlet. The valve at all times should be free from the
discharge piping. The riser pipe should be large enough
to accommodate the full capacity of the valve without
causing a back pressure build up on the valve.
VI. Handling and Storage
VII. Pre-Installation & Installation Instructions
Do not lift valve
horizontally, hook to
lifting lever or spring.
Prevent dirt from
entering valve outlet
port.
Handle valve carefully.
Do not drop or strike.

10 | Baker Hughes © 2020 Baker Hughes Company. All rights reserved.
IX. Consolidated 2478 Series Relief Valves
9
11
20
10
7
6
2
3
1
8
4
5
7
13
19
18
9
10
6
20
15
17
14
16
12
Figure 1: 2478 Standard Soft Seat Design
Figure 2: Packed Cap Assembly
Ref
No. Nomenclature
1 Base
2 Bonnet
3 Disc
4 Seat Washer
5 Soft Seat Retainer Ring
6 Spindle
7 Spring Washer
8 Spring
9 Compression Screw
10 Compression Screw Locknut
11 Screwed Cap
12 Lever
13 Packed Cap
14 Cam Shaft
15 Bushing
16 Drive Screw
17 O-Ring
18 Release Nut
19 Release Locknut
20 O-Ring Gasket

Consolidated 2478 Series Pressure Relief Valve Manual | 11
© 2020 Baker Hughes Company. All rights reserved.
During system operating conditions, the spring force
applied due to compression screw is higher than the
upward acting pressure force on the disc. As a result,
the valve is in the closed position. When system
pressure reaches the opening pressure of the valve,
the upward acting pressure force equals the downward
acting spring force, hence valve begins to open. If
system pressure increases more than the opening
pressure, the valve opens proportionately. There is no
pop type action on the liquid valve due to an absence
of expansion characteristics in liquid (incompressible
fluid). The valve lift will depend upon the degree of
overpressure. During the lifting action, the disc is guided
in precisely machine bonnet guiding surface. The valve
closes, once system pressure reaches closing pressure
of the valve.
X. Operating Principle
1. Remove Screwed Cap or Packed Cap-Lever assembly.
2. Remove Release Nut and Release Locknuts in valves with cap-lever
assembly.
3. Release Compression Screw Locknut and release spring compression by
turning Compression Screw counter-clockwise.
4. With valve Base held in vise loosen Bonnet to Base connection (use strap
wrench, do not use pipe wrench as this may crush the bonnet).
5. Holding Bonnet upside down, unscrew and remove Base.
6. With one hand on Disc, rotate valve over and remove Disc, Spindle, Spring
and Spring Washer Assembly from Bonnet.
7. Remove Disc by pulling the Spindle out of Disc pocket.
8. If Soft Seat is damaged as shown by nicks, cuts and dents, remove Retainer
Ring by a sharp tool. Subsequently, remove Soft Seat using the same tool.
These two parts must not be used again.
XI. Disassembly of 2478 Series Relief Valve
Do not disassemble
valve with pressure in
drum or header, as this
will result in severe
personal injury or death.

12 | Baker Hughes © 2020 Baker Hughes Company. All rights reserved.
The valve repair operation will depend upon the damage.
In some cases, it is easier to replace the part. In a
number of cases, only the nozzle and disc need to be
repaired. This can be done in the following manner:
1. If the disc is damaged by nicks, cuts, dents on the
soft seat, it is to be replaced by using any sharp
tool to pull out the retaining ring, then soft seat. See
Reassembly Procedure for installing new soft seat.
2. Lapping a at seat is extremely simple. No special
skill is required and the technique is readily apparent
after a few minutes of actual lapping.
3. The following precautions and hints will enable
anyone to do a “Professional” job of lapping seats.
a. Keep the work clean.
b. Always use a fresh lap. If signs of wearing (out of
atness) are evident, recondition the lap.
c. Apply a very thin layer of compound to the lap.
This will prevent rounding o󰀨 the edges of the
seat.
d. Keep the lap squarely on the at surface and
avoid any tendency to rock the lap which will
cause rounding of the seat.
e. When lapping the Base keep a rm grip on the
lap or part to prevent the possibility of dropping it
and damaging the seat.
f. Lap, using a reciprocating motion in all
directions, at the same time applying uniform
pressure and rotating the lap or the part slowly. If
reconditioning necessitates removing more than
.010” (0.03 mm), replace the base.
g. Replace the compound frequently after wiping o󰀨
the old compound, and apply more pressure to
speed the cutting action of the compound.
h. To check the seating surfaces, remove all
compound from the lap. Then, shine up the
seat with the same lap using the lapping motion
described above. Low sections on the seating
surface will show up as a shadow in contrast to
the shiny portion. If shadows are present, further
lapping is necessary, and only laps known to be
at should now be used. Only a few minutes will
be required to remove the shadows.
i. When the lapping is completed, any lines
appearing as cross scratches can be removed by
rotating the lap which has been wiped clean of
compound on the seat about its own axis.
j. The seat should now be thoroughly cleaned with
kerosene, light oil, or carbon tetrachloride, using
a lint-free cloth or tissue paper.
XII. Inspection and Part Replacement

Consolidated 2478 Series Pressure Relief Valve Manual | 13
© 2020 Baker Hughes Company. All rights reserved.
XIII. Reassembly of 2478 Series Relief Valve
Figure 3: 2478 Soft Seat Assembly
1. Clean seats and all parts
2. Disc Assembly:
a. Clean disc and place it on a level metallic plate
as shown in Figure 3. Disc surface having the
spindle pocket will lie on the metal plate.
b. Pick-up proper soft seat; clean this with lint free
cloth. Inspect it for nicks, cuts, dents (defective
soft seat should be rejected). Place soft seat
onto the disc as shown in Figure 3.
c. Pick-up proper retaining ring and tool assembly
(see Table 1). Place retaining ring on the disc
post (see Figure 3). Subsequently put the
retaining ring tool assembly in a mechanical
press (not shown in Figure 3). By applying slight
force, position retaining ring over the disc post.
Inspect the ring to ensure its proper positioning.
Subsequently, press the ring hard enough to
move it down to provide tight retaining of the
soft seat. A properly assembled soft seat will be
somewhat compressed by the retaining ring.
3. Place spindle into disc pocket.
4. Insert disc, spindle, spring and spring washer
assembly into bonnet.
5. Holding bonnet upside down (so that disc will not
drop), install the base to the bonnet assembly.
Tighten bonnet on base using torque values:
D: 50 ft-lb (68 N-m), E: 60 ft-lb (81 N-m),
F: 65 ft-lb (88 N-m), G: 75 ft-lb (102 N-m),
H: 90 ft-lb (122 N-m), J: 100 ft-lb (136 N-m).
6. Assemble compression screw and provide
spring compression by two turns of compression
screw. The desired spring compression must be
established.
Table 1: 2478 Bronze Safety Valve
Soft Seat Assembly Tools
Valve Type Retaining Ring Assembly Tool
No.
2478D 2091155 7530163-1
2478E 2091156 7530163-3
2478F 2091157 7530163-5
2478G 2091158 7530163-7
2478H 2091160 7530163-9
2478J 2091162 7530163-11
Retainer Ring
Holding Tool
Disc
Post
Soft Seat
Retainer
Ring
Metal
Plate

14 | Baker Hughes © 2020 Baker Hughes Company. All rights reserved.
XV. Trouble Shooting
Certain troubles may develop through use or damage to
working parts. The most common are leakage, chattering,
hang-up, and set pressure variation.
Leakage is the constant escape of liquid at normal
operating pressure below the leak tightness pressure
of the valve. It is caused by either damage to the
seating surfaces or to foreign matter being trapped.
If during pressure testing or manual lifting, wide open
does not give relief, the valve should be repaired at
the first opportunity to prevent further damage. Another
cause of leakage is a bent spindle that causes hang-up
and improper installation of discharge piping so as to
introduce undue strain upon the valve.
Chattering is a hammering action of a vibratory nature
of the disc on the nozzle seat and must be stopped
immediately to protect the seating surface. Chattering
is caused by excessive back pressure from undersized
discharge piping, insufficient flow compared to the rated
flow and an undersized or closed vent hole in the bonnet
outlet.
Hang-up occurs upon closing and is defined as leakage
from the valve failing to shut-off tightly. Mechanical
interference is the primary cause. Disc and disc guiding
area in the bonnet should be examined.
Set pressure variation may be caused by spring
relaxation, damage to the seats from foreign matter,
from chatter or difference in thermal conditions between
various test runs.
The drop off in opening pressure due to spring relaxation
may be caused by excessive valve lift in the event of
excessive discharge beyond rated flow. The compression
screw can be adjusted to provide desire set pressure.
However, this should be done for temporary relief. The
relaxed spring should be replaced with a new one.
Between initial and subsequent test runs, the soft seat
settles a little bit providing a drop off in opening pressure.
However, three consecutive tests runs within opening
pressure tolerance should indicate settling of the soft
seat. Any drop in opening pressure can be corrected by
turning compression screw clockwise and by verifying the
opening pressure by test.
XIV. Setting and Testing
To change opening pressure of the valve, loosen the
locknut. Turn the compression screw clockwise to
increase pressure or counter-clockwise to decrease
pressure. The opening pressure of the valve is indicated
by the first continuous discharge of the liquid through
outlet. Before opening, in a number of cases, liquid will
discharge one drop at a time. This is not to be confused
with valve opening pressure. This should happen beyond
the leak tightness pressure of the valve and before its
opening pressure.

Consolidated 2478 Series Pressure Relief Valve Manual | 15
© 2020 Baker Hughes Company. All rights reserved.
Ordering Information
Inlet Size
Type Designation
1.500 - 2478 H - XDAI
Soft Seal
Orifice Designation
XVI. Replacement Parts Planning
The next time replacement parts are needed, keep these
points in mind:
• Baker Hughes designed the parts
• Baker Hughes guarantees the parts
• Consolidated valve products have been in
use since 1879
• Baker Hughes has worldwide service
• Baker Hughes has fast response availability for
parts with the global Green Tag Center (GTC) or
Authorized Consolidated Sales Representatives
network.
XVII. Genuine Consolidated Parts
A. Basic Guidelines
The basic objectives in formulating a replacement parts
plan are:
• PROMPT AVAILABILITY
• MINIMUM DOWNTIME
• SENSIBLE COST
• SOURCE CONTROL
Consult the Recommended Spare Parts list (see Section
XVIII of this manual) to dene the parts to be included in
the inventory plan.
Select parts and specify quantities.
B. Identication and Ordering
Essentials
When ordering service parts, please furnish the following
information to ensure receiving the correct replacement
parts:
Specify parts required by:
1. Part Name (See Figures 1 to 2).
2. Part Number (if known)
3. Quantity
Contact your local Green Tag Center (GTC).

16 | Baker Hughes © 2020 Baker Hughes Company. All rights reserved.
Table 3: Component:
Soft Seat Disc
Valve
Type
4266601 4266701 4266801 4266901 4267001 4267101
2478D X
2478E X
2478F X
2478G X
2478H X
2478J X
XVIII. Recommended Spare Parts
The recommended spare parts/tools are spring, disc,
soft seat, retaining ring and retaining ring assembly
tools. When ordering replacement or spare parts, state
type, size, and set pressure of the valve, and fluid type.
Refer to Consolidated 2478 Series Relief Valve catalog
for more detailed information on parts descriptions and
nomenclatures.
Table 4: Component:
Retainer Ring
Valve
Type
2091155 2091156 2091157 2091158 2091160 2091162
2478D X
2478E X
2478F X
2478G X
2478H X
2478J X
Table 5: Component:
Spring Washers (2)
Valve
Type
VBG906B VBA906 VAW906 VBH906 VAU906 4342601
2478D X
2478E X
2478F X
2478G X
2478H X
2478J X

Consolidated 2478 Series Pressure Relief Valve Manual | 17
© 2020 Baker Hughes Company. All rights reserved.
A. Field Service
Utilities and Process Industries expect and demand
service at a moment’s notice. Baker Hughes’s Field
Service can be depended upon for prompt response,
even in extreme o󰀨-hour emergency situations.
Baker Hughes maintains the largest and most competent
eld service sta󰀨 in the industry. Service Engineers are
located at strategic points throughout the United States
to respond to customer’s requirements for service.
Each Service Engineer is factory trained and long
experienced in servicing safety valves. Baker Hughes
Service Engineers restore disc and seat bushing critical
dimensions which a󰀨ect valve performance, and are
capable of modernizing valves in the eld.
It is highly recommended that the professional talents of
a Baker Hughes Field Service Engineer be employed to
make nal eld adjustments during the initial setting of
all Consolidated Safety Valves.
B. Factory Repair Facilities
Baker Hughes Consolidated factory maintains a
Repair Center. The repair department, in conjunction
with the manufacturing facilities, is equipped to
perform specialized repairs and product modications,
e.g., bushing replacements, hydroset calibrations,
electromatic relief valve repairs, etc.
C. Relief Valve
Maintenance Training
Rising costs of maintenance and repair in the Utility
and Process Industries indicate the need for trained
maintenance personnel. Baker Hughes conducts
service seminars that can help your maintenance and
engineering personnel to reduce these costs.
Seminars, conducted either at your site, or at our
manufacturing plant, provide participants with an
introduction to the basics of preventative maintenance.
These seminars help to minimize downtime, reduce
unplanned repairs and increase valve safety. While
they do not make “instant” experts, they do provide
the participants with “Hands On” experience with
Consolidated valves. The seminar also includes valve
terminology and nomenclature, component inspection,
trouble shooting, setting and testing, with emphasis on
the ASME Boiler and Pressure Vessel Code.
For further information, please contact your local
Green Tag Center (GTC).
XIX. Manufacturer’s Field Service & Repair Program

Tech Field Support & Warranty:
Phone: [phone]
valvesuppor[email protected]
bakerhughes.com
Copyright 2020 Baker Hughes Company. All rights reserved. Baker Hughes provides this information on
an “as is” basis for general information purposes. Baker Hughes does not make any representation as to
the accuracy or completeness of the information and makes no warranties of any kind, specic, implied or
oral, to the fullest extent permissible by law, including those of merchantability and tness for a particular
purpose or use. Baker Hughes hereby disclaims any and all liability for any direct, indirect, consequential or
special damages, claims for lost prots, or third party claims arising from the use of the information, whether
a claim is asserted in contract, tort, or otherwise. Baker Hughes reserves the right to make changes in
specications and features shown herein, or discontinue the product described at any time without notice or
obligation. Contact your Baker Hughes representative for the most current information. The Baker Hughes
logo, Consolidated, and Green Tag are trademarks of Baker Hughes Company. Other company names
and product names used in this document are the registered trademarks or trademarks of their respective
owners.
BHCN-2478-IOM-32529C-0520 05/2020
Direct Sales Office Locations
Find the nearest local Channel Partner in your area:
valves.bakerhughes.com/contact-us
valves.bakerhughes.com
Australia
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Phone: [phone]
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