Flow Safe F88 Series Instruction manual

F88 SERIES
SAFETY RELIEF VALVE
•PLASTIC SEATED
•- 3, - 4, - 8, - G, - J Orifices
(WITH BOLTED BONNET)
INSTALLATION,
OPERATION, & MAINTENANCE MANUAL
Revision: D
Date of Issue: Feb. 2, 2016
Approved by: GG jwo
Project Engineer Engineering Projects Dir.

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 2 of 15
TABLE OF CONTENTS
Topic Page
1.0 General............................................................................................. 3
2.0 Description, Operation, Service Envelope, Installation, & Startup
2.1 Description / Operation ..................................................................... 4
2.2 Service Envelope.............................................................................. 5
2.3 Installation......................................................................................... 5
2.4 Startup .............................................................................................. 6
3.0 Valve Maintenance
3.1 Disassembly ..................................................................................... 7
3.2 Reassembly ..................................................................................... 7
4.0 Valve Testing and Adjustment
4.1 Test Equipment................................................................................. 8
4.2 Setting / Adjustment Tolerances....................................................... 8
4.3 Set Pressure Adjustment .................................................................. 9
4.4 Seat Tightness.................................................................................. 9
4.5 Lift Lever Operation .......................................................................... 9
5.0 Accessories....................................................................................... 10
6.0 Troubleshooting Guide ..................................................................... 11
Illustrations
F88 Series Valve Assembly Illustrations...................................................... 13

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 3 of 15
1.0 GENERAL
1) This manual is intended to provide users with direction and guidance for the maintenance of
FLOW SAFE F88 Series safety relief valves. This manual indicates the proper method of valve
disassembly, soft goods replacement, and valve reassembly. FLOW SAFE provides this manual
as a guideline and reference only. It is not intended to serve as a training manual or
manufacturing guide. FLOW SAFE assumes no responsibility for personal or property damage
that may occur in conjunction with this manual.
2) FLOW SAFE recommends that all valves be placed on a regular maintenance schedule that
includes the routine replacement of softgoods. FLOW SAFE recommends softgoods
replacement every three years but cautions that each customer make their own determination
and set their own schedule based upon use and environment. FLOW SAFE believes that when
maintenance and reassembly is performed as outlined in this manual there is no safety hazard.
During routine maintenance the internal components of the valve should be inspected for damage
or abnormal wear. The valve should also be inspected for excessive corrosion. A corrosion
allowance of 0.06” (1.5 mm) is designed into all carbon steel components subject to corrosion.
Operating the valve with corrosion exceeding this allowance is not recommended.
Cycling the valve at least once a year is considered to be good practice to verify operation and to
confirm that parts are not seized.
3) When a new valve leaves FLOW SAFE, it has been manufactured and tested by trained and
experienced personnel. When you remove a valve from your system and perform the
maintenance tasks that are outlined herein you will need proper training.
Do not attempt to accomplish these tasks without adequate training and understanding of the
valve operation.
4) Any and all stated or implied warranties that are in effect during the purchase of a new FLOW
SAFE valve are null and void once the valve has been disassembled by someone other than
approved FLOW SAFE personnel.
All repair and resetting of "UV"-stamped safety relief valves should be performed either by FLOW
SAFE, Inc., or by a National Board-certified valve repair shop holding a "VR" (Valve Repair)
stamp.
5) It is highly recommended that all instructions herein be read in full prior to any assembly,
disassembly, or operation of this equipment.
6) The noted manufacturer’s standard lubricants should be used only if compatible with process fluid
and application.
7) Specific design details described in this document are subject to change without notice.
8) Should the need arise for general assistance, contact the FLOW SAFE Sales or Service
department at [phone] or [phone] in Orchard Park NY or [phone] in
Houston TX. For more detailed technical assistance, contact the FLOW SAFE Engineering
department at [phone]. Product information may also be obtained from the Flow Safe
website at www.flowsafe.com.

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 4 of 15
2.0 DESCRIPTION, OPERATION, SERVICE ENVELOPE,
INSTALLATION, and STARTUP
2.1 DESCRIPTION / OPERATION
The FLOW SAFE F88 Series safety relief valve is a direct-acting spring-loaded relief valve, suitable for
gas or liquid service. The Type F88 is plastic-seated with a plastic seal.
Orifice sizes are available in -3, -4, -8, -G, and -J with set pressures as referenced in 2.2.
Blowdown is nonadjustable, designed to be approximately 20%. At low flow rates on liquids, the valve
tends to modulate and will reclose with this approximate blowdown value.

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 5 of 15
2.2 SERVICE ENVELOPE
BODY
ORIFICE SIZE
SIZE
- 3
- 4
- 8
- G
- J
Minimum
Set
Pressure,
psig (barg)
All
50
(3.5)
50
(3.5)
50
(3.5)
50
(3.5)
50
(3.5)
Maximum
Set
Pressure,
psig (barg)
C, D, E Body w/
standard bonnet
720
(49.6)
720
(49.6)
720
(49.6)
668
(46)
298
(20.5)
C, D, E Body w/
XL bonnet
4292
(296)
4292
(296)
4292
(296)
3705
(255)
2700
(186)
C Body w/
XXL bonnet
(Liquid only)
8382
(578)
8382
(578)
----
----
----
* Confirm service / application with factory.
2.3 INSTALLATION
Prior to installation, check that the set pressure on the nameplate is as required, and meets the system
requirements.
The F88 Series safety relief valve should be installed in the upright position per the figure on the next
page, as close as possible to the pressure source, to minimize pressure losses between the system and
the valve. This should be in accordance with accepted piping practices, as set forth in the API 520 Part II,
which recommends that inlet piping pressure losses should not exceed 3% of the set pressure when the
valve is flowing.
The valve discharge pipe should be sufficiently large so that backpressure does not exceed system
design conditions when relieving. High backpressure may diminish capacity below the value assumed
during the valve’s sizing and selection process.
SOFT
GOODS
Temperature,oF ( oC)
F88 Seats
MAX.
MIN. *
PI / PAI / Vespel
PEEK
Teflon (PTFE)
Kel-F (PCTFE)
500 (260)
525 (273)
400 (204)
400 (204)
-423 (-252)
0 (-18)
-423 (-252)
-423 (-252)
F88 Seals
Teflon (PTFE)
400 (204)
-423 (-252)

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 6 of 15
F88 Series valves are balanced against superimposed backpressure,
so that the set pressure will not change with backpressure.
Make sure that the inlet piping/flanges have an opening equal
to or greater than the valve's inlet diameter. Make sure that there
are no obstructions like gaskets, fittings, etc., in the flow path
to restrict the flow or cause chatter. Also, misaligned piping connections
may result in leaks or induce stresses in the valve assembly that interfere
with good operation. Discharge stacks exposed to the elements should
be configured so as to avoid the accumulation of snow and ice.
If a block valve is used below the relief valve, it should be opened before
pressurizing the system. This block valve should be locked open during
normal system operation.
Use only the wrench flats on the valve inlet bushing, taking care not to
make any wrench marks, for tightening and installation. Do not wrench
on the cast body or bonnet.
2.4 STARTUP
Foreign particles or dirt can damage the valve and make it inoperative. Prior to installation, clean out the
piping thoroughly. If the valve is not installed immediately, inlet and outlet connections should be
protected and covered.
Pressure can be applied to the valve as system pressure increases, or by opening the block valve (if
there is one) after the system has attained operating pressure. Verify the valve seat is leak-tight, in
accordance with Section 4.4.
The valve is now ready for service. Inspection and maintenance should be performed on a regular basis,
typically once a year, depending on the service conditions.

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 7 of 15
3.0 VALVE MAINTENANCE
WARNING: It is extremely dangerous to disassemble any valve while it remains in service
with incoming line pressure. Also, improper assembly of the valve may result in
leakage or failure of the valve when returned to service.
3.1 DISASSEMBLY
(See Illustrations on Pages 13 through 15)
1) Remove the valve from service, using only the wrench flats on the inlet bushing, or adequately
and safely block the incoming pressure before disassembling the valve and performing
maintenance. NOTE: If bushing remains connected to the system piping, then the valve's
spindle will fall out of the body as it is removed.
2) Cut and remove the lockwire.
3) For valves with lift lever, first remove the lock nut and lift lever. Slowly unscrew the bushing,
holding shaft. Unscrew the lift lever housing.
4) Remove the pressure adjusting (PA) screw cap. Measure the height of the PA screw above the
body and record value. For valves with lift lever, measure the distance from the jam nut to top of
threaded lifting rod. Then remove jam nut and lift nut.
5) Loosen the PA screw lock nut. Loosen PA screw until the spring load is removed.
6) Unscrew and remove the four bolts, nuts, and lockwashers between the body and bonnet.
Remove spring washer(s) and spring, and lifting rod subassembly (if applicable). Remove the
bonnet, including attached bonnet base if an older F88-4 or –8 “large body” with the base held to
the bonnet by a retaining ring.
7) Unscrew and remove the bushing, using wrench flats.
8) Remove the spindle assembly. Remove retainer screw, retainer, and seat. Remove spindle
cap,using the wrench flats, and spindle seal.
9) Replace the softgoods per the instructions in Section 3.2.
•Replacement parts may be found in the appropriate FLOW SAFE softgoods kit, as listed
in Section 5.0 of this manual.
3.2 REASSEMBLY
1) Reassembly of these valves is basically the reverse of the disassembly.
NOTE: Care must be taken in the handling of all items, particularly softgoods.
2) Inspect condition of nozzle seating surface and spindle guide surface inside body. Buff out or
polish any scratches that may interfere with a good seal, or replace part if necessary.
3) Apply Neverseez or DuPont Krytox (for oxygen service) to all straight threads.
4) Insert the plastic seat, seat retainer, and retainer screw into the spindle. Install the seat dry.
Apply Loctite or Vibra-tite to retainer screw threads. As screw is tightened, ensure that it meets
firm resistance against the locking Heli-Coil in spindle.
5) Carefully install new spindle seal in recess on spindle, with spring side facing spindle shoulder.
Ensure that spindle cap tightens firmly against its locking Heli-Coil. Desco 600 grease should be
applied to the outside of the spindle seal, except for cryogenic service or for -3, -4, and -8 valves
below 100 psig, Dow Corning 33 or 55 (or Molykote) should be used.
6) Insert the spindle assembly into the body, making sure that it travels freely on the guide surface.
7) Position the bushing seal on the appropriate shoulder of the bushing.
8) Screw the bushing / seal assembly into the body and tighten using the wrench flats.

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 8 of 15
9) Assemble the spring washer(s), spring, and lifting rod subassembly (if applicable) into the bonnet.
10) Assemble the bonnet, adapter plate (for XXL “C” bonnet), bolts, nuts, and lockwashers to the
body. Torque main bonnet bolts to following value:
12-15 ft-lbs -- 3/8-in bolts marked “B8” on ‘C’ body
25-30 ft-lbs -- 1/2-in bolts marked “B8” on ‘D’ or ‘E’ body
65-70 ft-lbs -- 1/2-in bolts marked “B8” on ‘D’ or ‘E’ body
11) Screw the PA screw, lock nut, and seal into the top of the body, with top of screw at previously
recorded value.
12) For lift levers, assemble PA screw, and lock nut around lifting rod. Then reassemble the lift nut
and jam nut to previously recorded position. Assemble the lift lever housing and then the
bushing, seals, shaft, lift lever, and lock nut.
13) Ensure that the rear bolt and seal are secured in the back of the body.
14) The valve is now completely assembled and ready to be tested. See Section 4.0.
4.0 VALVE TESTING AND ADJUSTMENT
The following tests and adjustments are necessary for F88 safety relief valves: set pressure and seat
tightness. Blowdown is not adjustable, and is fixed at approximately 10%-30% of set pressure,
depending on valve size, service media and set pressure.
4.1 TEST EQUIPMENT
F88’s for gas service should be set using air. Where practical, F88’s for liquid service should be set using
water or other suitable liquid. To obtain full-flow conditions and observe blowdown, a sufficiently large
pressure vessel will be needed.
4.2 SETTING / ADJUSTMENT TOLERANCES
Set Pressure: Set Pressure Tolerance
> 70 psig + 3% of specified set pressure
< 70 psig + 2 psi
Seat Tightness: There should be ZERO leakage with inlet pressure at or below:
For gas service:
•0.90 x set pressure
For liquid service:
•0.90 x set pressure, if set pressure > 100 psig
•0.80 x set pressure, if set pressure < 100 psig

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 9 of 15
4.3 SET PRESSURE ADJUSTMENT
NOTES: 1. If the set pressure is being changed, then the spring, spring washer, PA screw, and
bonnet may need to be changed. Consult the factory or an authorized FLOW
SAFE assembler for the correct parts.
2. Set pressure for F88’s on liquid service is defined as 93% of the “gush” (pop)
pressure. This corresponds to the first steady stream if valve is being set on a low-
capacity test system. For gas or vapor service, set pressure is “pop”.
1) Remove the PA screw cap (if installed), loosen the PA screw lock nut, and screw the PA screw in
(clockwise) most of the way.
2) FOR GAS SERVICE VALVES: Increase the inlet pressure to the desired level, and then unscrew
(counterclockwise) the PA screw until the valve pops.
FOR LIQUID SERVICE VALVES: Increase the inlet pressure to 1.075 (1 0.93) of the nameplate
set pressure, and then unscrew (counterclockwise) the PA screw until the valve “gushes” liquid.
Full rated flow for the valve will occur within 110% of set pressure (approx. 102% of “gush”
pressure).
3) Tighten down the lock nut and retest. Readjust as required.
4) Install and tighten down the PA screw cap or lift lever housing. Test valve one more time.
4.4 SEAT TIGHTNESS
1) After any repairs and set pressure adjustments, seat tightness should meet the criteria stated in
Section 4.2.
2) If the valve leaks after repair, refer to the troubleshooting guide on Pages 11 & 12. Check for:
•Even seating between the spindle and bushing. With the F88’s, you should be able to
see a full circular line contact on the bushing surface. Make sure that the seat is installed
all the way in the spindle and that the retainer is tight.
•Foreign particles trapped between the seat and bushing. If found, they may have
damaged the seat, requiring that it be replaced.
•Scratches in the beveled seating area of the nozzle (bushing).
4.5 LIFT LEVER OPERATION
CAUTION: Do not operate a lift lever unless valve inlet pressure is at least 75% of nameplate set
pressure. Prepare the system as necessary to handle a discharge from the valve.
NOTE: The lift lever enables verification that the valve spindle and seat can open freely, but does
not allow set pressure to be verified.
1) With inlet pressure as stated in the above CAUTION, rotate the lift lever handle clockwise or
counterclockwise until it meets resistance.
2) Continue rotating the handle slowly until there is indication of flow through the valve. NOTE that,
if inlet pressure is greater than reseat pressure (approx. 80% of set pressure), the valve may
develop full flow (gush) and will stay open long enough to blow down to that pressure.
3) Return the lift lever handle to the down position. If flow through valve could not be achieved, or if
the valve does not close, have the valve disassembled and serviced by a qualified organization.

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 10 of 15
5.0 ACCESSORIES
1) Softgoods Kits
Orifice
Std. Kit P/N
Lift Lever Kit P/N
- 3 / -4 / -8
- G
- J
F88-C-XT
F88-G-XT
F88-J-XT
F88-CL-XT
F88-GL-XT
F88-JL-XT
Most common materials listed; contact Flow Safe for availability of other materials.
Bushing seal and rear seal are Teflon.
SOFTGOODS KIT CONTENTS (See Pages 13 through 15)
Standard SG Kit: Lift Lever SG Kit (includes Std. items):
Qty. Description Qty. Description
1 Seat 2 Shaft crush ring
1 Bushing seal 1 Bushing crush ring
1 Rear seal
1 Spindle seal
2) Lift Lever Kits
Contact factory
Code
X= Seat Material
T
K
W
P
F
PTFE / Teflon
PCTFE / Kel-F
PI / PAI / Vespel
PEEK
Ekonol-filled Teflon

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 11 of 15
6.0 TROUBLESHOOTING GUIDE:
Symptom
Possible Cause
Remedy
The valve leaks around
the bushing.
Inadequate bushing torque.
Tighten until the bushing bottoms firmly
on the body.
Sealing surface on body or
bushing is damaged.
Inspect and polish sealing surfaces.
Bushing seal is damaged or
contaminated.
Remove bushing seal. If damaged,
replace with new seal. If contaminated,
clean and replace.
The valve leaks through
the outlet.
Seat or nozzle seating surface is
damaged or contaminated.
Disassemble the valve, remove the
spindle, and examine the seat and
seating surface under magnification. If
damaged, replace with new seat; if
contaminated, clean and reinstall.
Uneven torque on body-to-bonnet
bolts.
Torque bolts evenly (see Section 3.2 for
values)
The valve leaks through
the atmospheric vent
hole in bonnet.
Worn / damaged spindle seal.
Disassemble valve, remove spindle
assembly, and inspect spindle and seal
on upper neck. Look for nicks, tears, or
flat spots. Replace as necessary.
Pipe plugs are not installed
properly.
Tighten or reinstall plug(s).
The valve does not
close.
The spindle is stuck.
Disassemble and check for binding.
Deburr or replace parts.
The valve opens below
the designated set point.
The spring preload is low due to
misadjustment, vibration, or other.
Adjust pressure adjusting screw in
(clockwise). Ensure PA screw lock nut
and cap are tight.
The seat leaks due to possible
damage, allowing early simmer
and pop.
Disassemble and inspect seat; replace
if damaged.
Spring washer is not in proper
contact with spindle.
Ensure that dimpled area of spring
washer is aligned with top of spindle.
The valve opens above
the designated set point.
The spring preload is high.
Adjust PA screw out (counterclockwise).
The spindle is stuck or sticking.
Disassemble and check for binding.
Deburr or replace parts.

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 12 of 15
6.0 TROUBLESHOOTING GUIDE (continued):
Symptom
Possible Cause
Remedy
The valve does not
open.
Spindle is stuck closed.
Disassemble the valve and examine the
sliding surfaces. If damaged, replace.
If contaminated, clean.
Nozzle is stuck to seat.
Disassemble and check seat for
permanent impression(s). Harder seat
material may be needed.
The set pressure has not been
reached.
Increase inlet pressure. Confirm
pressure gage is calibrated.
Isolation valve is closed.
Open isolation (block) valve.
The valve chatters or
rapid-cycles.
The valve is oversized for the
application.
Install smaller valve.
The inlet is choked.
Increase size of inlet piping to be equal
to or greater than the valve orifice.
Check for piping restrictions or partially
closed valves.
Too much built-up backpressure
due to excessive flow, or outlet
piping undersized or too long.
Reduce backpressure by reducing flow
rate or reworking outlet piping (increase
size; shorten; reduce number of turns).
It is recommended that outlet piping
size be equal to or greater than the
valve outlet size.

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 13 of 15
F88 SERIES VALVE ASSEMBLY ILLUSTRATIONS
See Page 15 for
typical lift lever assembly.

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 14 of 15
F88 SERIES VALVE ASSEMBLY ILLUSTRATIONS
(continued)

INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE: F88 Series Safety Relief Valve Rev. D Page 15 of 15
F88 SERIES VALVE ASSEMBLY ILLUSTRATIONS
(continued)
F88 Series Manual DUS.FS.0016
03.21