Overpressure Relief / Bleed Valve Overhaul Procedures - Kirby Morgan 77 Operation And Maintenance Manual

7.15 Overpressure Relief / Bleed
Valve Overhaul Procedures
Overpressure
Relief Valve Seat
Spring
Over Pressure Relief Valve Component breakdown
7.15.1 Overpressure Relief Valve
The relief/bleed valve should always be used on all
Emergency Gas Supply (EGS/bail-out) first stage
regulators to prevent the hose from rupturing in the
event the first stage pressure creeps. The Kirby Mor-
gan relief valve body is made of stainless steel.
The basic components last a long time but the valve
should be disassembled, cleaned, and inspected at
least once a year or whenever it fails testing. The valve
should be tested monthly. Cleaning and overhaul is
easily performed using a nylon toothbrush and a 50/50
solution of vinegar and fresh water. Cleaning for 15
minutes in an ultrasonic sink, if available, with the
50/50 vinegar solution is highly recommended.
Repair parts are available. Normal replacement parts
include the O-ring, soft seat, spring, and hex nut. The
O-ring should be replaced at least annually. The other
parts require replacement only if worn or damaged.
An exploded view of the valve is located in all KMDSI
Helmet and Band Mask Operations and Maintenance
Manuals. The text on the next three pages refers to
the drawing on this page.
Tools Required.
Torque wrench
1/2" open-end wrench attachment for torque wrench
1/8" Allen wrench
Nylon toothbrush
Vinegar, Fresh water
Mild dish soap
Ultrasonic sink, if available
Magnifying glass
New valve body o-ring
© ⅯⅯⅩIⅡ Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 130318003
Adjustment
Screw
O-ring
7.15.2 Overpressure Relief Valve
Disassembly and Cleaning
WARNING
Do not use cleaning solvents (i.e. min-
eral spirits, bleach, etc.) when cleaning
the relief/bleed valve. The use of clean-
ing solvents may lead to failure of the
relief/bleed valve.
1) Turn off the gas supply to the first stage regulator,
then bleed off any remaining pressure. Remove the
first stage regulator from the air/breathing gas source
so it cannot be accidentally turned on, i.e., pressurized.
Make sure the intermediate pressure in the regulator
hose is also fully drained of pressure.
2) Remove the relief/bleed valve from the regulator
body using the 1/2" open-end wrench.
3) Remove, cut, and discard the relief/bleed valve
body O-ring.
4) Using the 1/2" open-end wrench to hold the bleed/
relief body, use the 1/8" Allen wrench to remove the
Allen head adjustment screw. Then, shake out the
spring and soft seat.
5) Place all parts in the 50/50 solution of vinegar and
water and allow to soak for 15 to 30 minutes. If using
an ultrasonic sink, reduce time to 15 minutes.
6) Using the nylon toothbrush, brush all components
to remove corrosion and mineral deposits. Then, rinse
with fresh water and blow or air dry.
7) Using the magnifying glass, carefully inspect all
components for excessive corrosion and/or damage.
Replace the spring and/or adjustment nut, if either
part is excessively corroded or shows signs of wear
and/or damage.
Inspect the soft seat for nicks, cuts, and wear and
replace if any damage is found. Replace the entire
assembly if any damage to the valve body is present.
NOTE: A deep groove in the soft seat is normal.
Replacement is only necessary if the rubber seat is
deteriorated, cut, and/or chipped.
Kirby Morgan 77
®
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