Hawkeye Mfg MARSCH HAWK 4000 Series Technical Document

Marsh Hawk TRV Installation, Operation and Maintenance Guide - May 2022 1
NOTE: INFORMATION REQUIRED FOR SUCCESSFUL
INSTALLATION
CAUTION: INFORMATION IF NOT FOLLOWED MAY
RESULT IN DAMAGE OR INSTALLATION FAILURE
WARNING: INFORMATION IF NOT FOLLOWED MAY
RESULT IN INJURY OR DEATH
CONTENTS
PART A: INSTALLATION
A1 Marsh Hawk TRV Installation
A2 Marsh Hawk TRV Installation using bolt ring
A3 De-Icing System Installation
PART B: OPERATION
B1 Spider Cage (Internals) Removal
B2 Pressure Spacer Adjustment
PART C: MAINTENANCE
C1 Replacing Pressure / Vacuum Gasket
C2 Inspection & Re-lubrication
C3 Troubleshooting
C4 Antifreeze Solutions
PA R T A :
INSTALLING MARSH HAWK TRV
NOTE: THE MARSH HAWK TRV REQUIRES AN 8” API
12F FLANGE CONNECTION. IF MOUNTING DIRECT
LY ON A TANK ROOF WITHOUT SPOOL, NOZZLE
OR RISER, THE DEEPSET NATURE OF HATCH MAY
PRECLUDE INSTALLING FASTENERS ON THE INTERI
OR OF THE TANK. IN THIS CASE, A MARSH HAWK
TRV BOLT RING, PART# HRF8PSTUDSASM WILL BE
REQUIRED  SEE SECTION A2 FOR INSTALLATION
NOTES. ADAPTER SPOOLS TO MOUNT TO OTHER API
AND ANSI CONNECTIONS ARE AVAILABLE. SEE OUR
WEBSITE FOR MORE INFORMATION ON SPOOLS AND
RISERS.
A1 MARSH HAWK TRV INSTALLATION
TOOLS
»3/4 Box or Socket Wrench (torque wrench
recommended)
PARTS REQUIRED
»1 Marsh Hawk TRV
»1 8” API Tank Gasket
»16 1/2 UNC x 1-3/4 Bolts & Nuts
1. Place Tank Gasket on the 8” API Tank Flange and align
holes.
SCH 40
OR LIGHTER
NOZZLE
7.98” min
INSTALLATION, OPERATION AND MAINTENANCE GUIDE
SERIES 4000 MARSH HAWK
This document contains the recommended procedures for installing, operating and maintaining a Series 4000 Marsh Hawk Tank Relief Vent. Read and understand this document prior to
installing, operating or maintaining the Series 4000 Marsh Hawk TRV. Replaces May 2010 Installation and Maintenance Guide. Suitable for use with all Marsh Hawk TRVs manufactured
since August 2011.
2. Mount Marsh Hawk on base gasket and align holes.
3. Fasten with the supplied 1/2 UNC Bolts and Nuts
with the 3/4 Box or Socket Wrench. Use washers on
the Marsh Hawk side of the bolted connection. Install
hand-tight, then torque to 14 ft-lbs. Installation torques
over the recommended value may reduce long-term
sealing performance. Follow bolting pattern below.
5
6
7
8
19
10
11
12
13
14
15
16
2
3
4
8 API 12B
A2 INSTALLATION WITH BOLT RING
TOOLS
»3/4 Box or Socket Wrench (torque wrench
recommended)
PARTS REQUIRED
»1 Marsh Hawk TRV
»2 8” API Tank Gasket
»1 Bolt Ring, c./w studs & nuts
1. Align and place bolt ring on the 8” API Tank Opening,
ensuring gaskets are in place on both sides of the bolt
ring.
2. Install underside nuts ensuring a minimum 1/4” of
thread is exposed on the stud when nuts are secured.
Install hand tight, then torque to 14 ft-lbs. Follow
bolting pattern in A1, step 3.
.25 MIN.25 MIN
3. Align studs with holes in Marsh Hawk TRV mounting
flange and drop into place.
4. Install remaining nuts. Install hand-tight, then torque to
14 ft-lbs. Installation torques over the recommended
value may reduce long-term sealing performance
Follow bolting pattern in A1 step 3.

Marsh Hawk TRV Installation, Operation and Maintenance Guide - May 20222
A3 DEICING SYSTEM INSTALLATION
TOOLS
»5/8 Box Wrench
PARTS REQUIRED
»1 De-Icing system
»Quick Coupling / Anti Freeze Pump
1. If the Marsh Hawk does not have the ¼ NPT ports
shown below, drill and tap a port in one of these
locations.
1/4 NPT
PORT
1.75
45°
45°
2. Thread the ¼ NPT nozzle into the port and tighten until
the nozzle flat is facing down into the Marsh Hawk
with the word “TOP” facing upwards.
3. Run the hose to an easily accessible location or to your
antifreeze injection system. The free end of the De-icing
System can be connected directly to an antifreeze
injection system or can be equipped with quick
connect fittings to a portable antifreeze pump. Refer to
C4 for gasket/antifreeze agent compatibility.
TO ANTIFREEZE PUMP
OR QUICK COUPLER
PART B:
OPERATING MARSH HAWK TRV
B1 SPIDER CAGE (INTERNALS) REMOVAL
WARNING: DO NOT REMOVE SPIDER CAGE WHILE
THE TANK IS UNDER PRESSURE.
1. Relieve the tank pressure by pressing down on
the pre-relief button (if equipped) until flow
through the vent is no longer heard or felt, or
by opening a secondary pressure relief valve.
PUSH AND HOLD
2. Remove the Spider Cage assembly by pressing down
on spring retainer and rotating counter clockwise to
disengage for J-slot. Keep two hands on the Spider
Cage in case there is residual pressure in the tank.
3. Lift the Spider Cage assembly straight out of the hatch
body.
B2 PRESSURE SPACER ADJUSTMENT
NOTE: ACTIVATION PRESSURE SHOULD BE 2  4 OZSI
BELOW THE EXPECTED OPERATING PRESSURE, AND
SHOULD NOT EXCEED THE THE DESIGN PRESSURE OF
THE TANK.
TOOLS
»1/2 Box Wrench
PARTS REQUIRED
»2 ozsi and 1 ozsi Pressure Spacers (As Required)
1. Remove the Spider Cage as per A2.
2. Determine the current pressure setting. The spring
installed without any spacers will have a pressure
setting of 2 ozsi. Each 0.11” and standard (0.22”)
spacer installed increase the pressure setting by 1 ozsi
and 2 ozsi respectively. E.G. two 0.22” spacers are
installed –> 2 ozsi + 2 * 2 ozsi = 6 ozsi
2 STANDARD
SPACERS
3. Use spring retainer to compress the spring. Remove the
retainer screw with the 1/2 wrench, and remove the
spring retainer.
4. Add or remove pressure spacers to increase or
decrease activation pressure, respectively. Follow
direction in reverse to reassemble the thief hatch.
P P

Marsh Hawk TRV Installation, Operation and Maintenance Guide - May 2022 3
PART C:
MAINTAINING MARSH HAWK
TRV
C1 REPLACING PRESSURE /
VACUUM GASKET
Hawkeye offers four gasket material options for the Marsh
Hawk TRV: FKM (Viton) [Standard], FEPM (Aflas), eFKM
(Sponge Viton), and FFKM (Kalrez). Gasket materials are
identified using ID holes stamped into the bolt circle of the
gasket, and marked with paint.
FKM/VITON
eFKM/
SPONGE VITON
FEPM / AFLAS
FFKM / KALREZ
Please ensure the selected gasket materials are suitable
for the your application prior to ordering a replacement
gasket. Call us for more information. The operating
temperatures below are for information only.
-50
0 50 100 150 200 250 300 350
TOOLS
»9/64 Allen Key
PARTS REQUIRED
»1 Replacment Gasket
»Dow #4 Electrical Insulating Compound
»Retaining Compound (Loctite Green 680 or eq.)
1. Remove the Spider Cage as per A2.
2. Remove the 12 #8-32 NC Socket Head Cap Screws
with the 9/64 Allen wrench, freeing the gasket
retaining ring.
3. Using light pressure, push the vacuum plate out of
the way, and slide the gasket around it and off of the
Spider Cage.
4. Place a drop of green retaining compound in each
hole of the retaining ring. Align holes on new gasket
with holes on Spider Cage and retaining ring. Replace
the 12 #8-32 NC Socket Head Cap screws, torquing
to 10 in-lb (5 in-lb for sponge gaskets). Reapply
sealant on gasket surfaces, per Part C2, step 7.
C2 INSPECTION AND RELUBRICATION
Generally, the more active the vent action of the TRV, the
more frequent re-lubrication should be performed. Specific
re-lubrication requirements are application specific, and
are determined by the following variables:
»Chemical Exposure
»Elevated Pressure
»High Flow Velocity
»Elevated Temperature
»Utilization (i.e. TRV is used as primary relief)
NOTE: DOW CORNING #4 ELECTRICAL INSULAT
ING COMPOUND IS FACTORYAPPLIED AT THE TIME
OF ASSEMBLY. RELUBRICATION USING THE SAME
PRODUCT IS STRONGLY RECOMMENDED FOR FIELD
RELUBRICATION.
Factory applied sealant has the following properties:
»Excellent seal and release properties
»-57°C to 204°C operating temperature
»Moisture-resistant
»Non-toxic an odorless
PARTS REQUIRED
»Dow #4 Electrical Insulating Compound
1. Remove the Spider Cage as per A2.
2. Inspect the pressure and vacuum seals. Look for signs
of wear, cracking, swelling, dryness, pitting, tearing
and improper positioning. Replace if damaged (See
Part C1).
PRESSURE
SEAL
VACUUM
SEAL
3. Inspect the 8” API tank gasket. Look for signs of wear,
cracking, swelling, dryness, pitting, tearing and
improper positioning. Ensure that the bolts are tight

Marsh Hawk TRV Installation, Operation and Maintenance Guide - May 20224
and the gasket is adequately compressed to prevent
leakage. Replace if damaged.
8" API
TANK GASKET
4. Inspect the Spider Cage. Ensure that all of the parts are
present and assembled as shown above. All bolts and
screws should be snug.
5. Inspect the springs. They should be under tension/
compression at all times and should therefore hold
the vacuum pallet against the vacuum seal and the
spring retainer against the top washer. If the vacuum
pallet does not stay closed on its own or the pressure
spring is loose when assembled, the springs have lost
their temper and should both be replaced. In severe
conditions Inconel springs may be required.
ENSURE SPRINGS MAINTAIN
TENSION/COMPRESSION
6. Inspect the Marsh Hawk body and inner sealing
surface. Look for signs of pitting, corrosion and wear.
Replace if damaged.
INSPECT BODY AND INNER
SEALING SURFACE
7. If everything clears inspection, apply the
recommended grease in an even coating on both the
pressure and vacuum seals as shown above.
APPLY RECOMMENDED
GREASE
8. Replace the Spider Cage and inject antifreeze agent
(Spider Cage removal in reverse)
C3 TROUBLESHOOTING
PROBLEM: Vent is Leaking of Frequently Opening
Symptom Of Solution
Unlubricated
Pressure / Vacuum
Seal
Perform the inspection and re-
lubrication procedures detailed
in C2. Ensure antifreeze agents
(if used) are compatible with
gasket material (see C4)
Worn or Damaged
Pressure Vacuum
Seal
Set pressure set too
close to operating
pressure
Ensure that the set pressure of
the Marsh Hawk is sufficiently
above the operating pressure
of the tank. Set pressure should
be 2 - 4 ozsi over operating
pressure.
PROBLEM: Vent is not opening
Symptom Of Solution
Debris blocking
action
Open lid and ensure the
vent cavity is clear of debris
and obstructions. If debris
accumulates, consider adding
a TRV Mesh Screen.
Stuck Pressure or
Vacuum Pallet
Remove the Spider Cage
assembly per B1 to ensure the
pressure and vacuum pallets
are free to move and are free
from ice. Ensure antifreeze
agents (if used) are compatible
with gasket material (see C4)
Set pressure set too
far from operating
pressure
Ensure that the set pressure of
the Marsh Hawk is sufficiently
below the desired relieving
pressure and the design
pressure of the tank.
C4 ANTIFREEZE SOLUTIONS
It is not recommended to use any kind of antifreeze
solution on a normally operating Marsh Hawk TRV, even
as a preventative measure unless there is evidence of the
valve icing up.
If antifreeze solutions are used, they must be compatible
with the gasket materials. Consult the chart below to
gauge general compatibility of common antifreeze agents
and Marsh Hawk TRV gasket materials. This list is not
exhaustive.
CAUTION: USING A NONRECOMMENDED ANTI
FREEZE AGENT CAN CAUSE THE MARSH HAWK TRV TO
FAIL TO OPERATE CORRECTLY, BY EITHER VENTING
CONTINUOUSLY OR SEALING CLOSED.
GASKET MATERIAL
ANTIFREEZE
SOLUTION
FKM &
eFKM
FEPM FFKM
Methanol 4 1 1
Ethanol 3 1 1
Isopropanol 1 1 1
Ethylene Glycol 1 1 1
1 - Satisfactory 2 - Fair 3 - Doubtful 4 - Avoid
Contents © Hawkeye Industries Inc. This document is uncontrolled, and is
subject to change without notice. Please refer to www.hawk-eye.com for the
most up-to-date product information.
2110 70 Ave NW
Edmonton, AB, Canada T6P 1N6
Toll Free: [phone]
Phone: [phone]
Fax: [phone]
www.hawk-eye.com
Printed in Canada.