Introduction - Aqua Lung MDB Technical Manual

Introduction

This manual provides factory prescribed proce-
dures for the correct service and repair of the Aqua
Lung product described in this manual. It is not
intended to be used as an instructional manual
for untrained personnel. The procedures outlined
within this manual are to be performed only by
personnel who have received Factory Authorized
training through an Aqua Lung Service & Repair
Seminar. If you do not completely understand all
of the procedures outlined in this manual, contact
Aqua Lung to speak directly with a Technical Advi-
sor before proceeding any further.
It is recommended that the MDB should be rinsed
in fresh water after use, and it should be stripped
down and serviced annually.
However, if at all unsure about the correct function-
ing of the MDB, then it must be officially inspected
immediately.
An Official Inspection consists of:
1. Testing instructions see Pre-Dive Inspection.
2. Orally inflate the MDB. Check that the over pres-
sure relief valve (OPRV)/rapid exhaust valve (REV)
are operating correctly, tightened down properly and
no leaks are detected.
3. A visual inspection of the MDB checking that
there is no excess wear to the hook/loop material,
stitching points are not excessively coming undone,
quick release buckles are in good working order and
outer bag zipper is moving freely.
4. Auxiliary cylinder is full and no leaks are detected. If
the MDB fails any of the 4 steps, it should be serviced
by an Aqua Lung trained service technician.
General Guidelines
1. In order to correctly perform the procedures
outlined in this manual, it is important to follow each
step exactly in the order given. Read over the entire
manual to become familiar with all procedures be-
fore attempting to disassemble the product in this
manual, and to learn which specialty tools and re-
placement parts will be required. Keep the manual
open beside you for reference while performing
each procedure. Do not rely on memory.
2. All service and repair should be carried out in
a work area specifically set up and equipped for
the task. Adequate lighting, cleanliness, and easy
access to all required tools are essential for an ef-
ficient repair facility.
3. As the valve/inflator is disassembled, reusable
components should be segregated and not allowed
to intermix with nonreusable parts or parts from
other units. Delicate parts, including inlet fittings
and crowns which contain critical sealing surfaces,
must be protected and isolated from other parts to
prevent damage during the cleaning procedure.
4. Use only genuine Aqua Lung® parts provided
in the overhaul parts kit for this product. DO NOT
attempt to substitute an Aqua Lung® part with an-
other manufacturer's, regardless of any similarity
in shape or size.
5. Do not attempt to reuse mandatory replacement
parts under any circumstances, regardless of the
amount of use the product has received since it was
manufactured or last serviced.
6. When reassembling, it is important to follow ev-
ery torque specification prescribed in this manual,
using a calibrated torque wrench. Most parts are
made of either marine brass or plastic, and can be
permanently damaged by excessive stress.
General conventions
Unless otherwise instructed, the following terminol-
ogy and techniques are assumed:
1. When instructed to remove, unscrew, or loosen
a threaded part, turn the part counterclockwise.
2. When instructed to install, screw in, or tighten
a threaded part, turn the part clockwise.
3. When instructed to remove an o-ring, use the
pinch method (see illustration below) if possible, or
use brass or plastic o-ring removal tool. Avoid using
hardened steel picks, as they may damage the o-
ring sealing surface. All o-rings that are removed are
discarded and replaced with brand new o-rings.
Pinch Method
Press upwards on sides of o-ring to
create a protrusion. Grab o-ring or
insert o-ring tool at protrusion.
5