Technical Addendum (Sections 1–4)
1. General Notes on the Neck Ring Assembly and Helmet Attachment Components
Although most neck ring and neck dam components across various Kirby Morgan helmet models are identical or very similar, all service must always be performed according to the specific manual for the helmet model being serviced. This ensures that any model‑specific differences in assembly methods, material specifications, or procedures are correctly followed.
Furthermore, it must be emphasized that all KM helmets must be equipped with an internal chin strap, which serves as a secondary retention system in the event the helmet should separate from the neck ring. While the inspection of this strap is included in the checklist, its functional importance warrants explicit mention here.
Sealed pull pins are factory‑filled with silicone oil. The presence of oil outside the pin, or reduced smoothness of operation, may indicate internal leakage. Servicing of these components should only be performed by personnel who have received proper manufacturer‑approved training, as incorrect handling may compromise the safety integrity of the helmet.
Metal components of the helmet must also be carefully inspected for corrosion, including discoloration, pitting, or microscopic cracks, as such damage can lead to sudden material failure without prior warning.
2. Notes on the Helmet Assembly Inspection
When inspecting the helmet shell, it is important to remove all non‑KMDSI factory stickers. This is particularly critical on fiberglass helmets, where incomplete inspection of the gelcoat and underlying structure may allow hidden damage to go unnoticed.
On fiberglass helmets, any damage that penetrates through the gelcoat into the fiberglass layer must be repaired immediately by a certified technician. Deep damage (1.5 mm or more) must be evaluated by a KMDSI/Dive Lab‑certified professional, and shell repairs may only be performed by personnel specifically authorized for helmet shell repair.
When handling the oral-nasal mask, it is essential that the nose block device is removed before the mask is removed or installed. Attempting to stretch the mask over the nose block will almost certainly result in tearing of the rubber.
The exhaust system must be assessed as a complete assembly, and even minor signs of rubber degradation are sufficient cause for immediate replacement. This includes small cracks, hardening, or early signs of material fatigue.
For stainless steel helmets equipped with a regulator pod, the pod does not need to be removed every year unless there are visible signs of internal corrosion. However, full removal, overhaul, and reinstallation is recommended at least every three years to ensure that hidden corrosion is identified before it becomes critical.
3. Additional Notes on the Side Block Inspection
The side block does not necessarily need to be removed every year, provided there are no signs of internal corrosion in its passages or valve components. However, all valves—one‑way valve, emergency valve, and steady‑flow valve—must be overhauled and fitted with new O‑rings at least once per year. This ensures correct performance under pressure and maintains a reliable safety margin.
It is also emphasized that the umbilical adapter must always be replaced with a new one during the annual service, regardless of its apparent condition. This component is exposed to mechanical stress and may develop microscopic deformation over time.
4. Notes Regarding the Demand Regulator
Although the checklist covers disassembly and replacement of soft goods in the regulator, it is important to clarify that regulator adjustment must only be performed after full disassembly and correct reassembly. The regulator cover must be assessed not only for visible damage but also for deformation of the airflow slots, as these are critical for proper regulator performance.
Any damage or wear in the purge button travel area is sufficient reason to replace the regulator cover. Older covers that have become thin, wavy, or show signs of material fatigue must also be replaced, even if no obvious damage is present.
The inlet valve adjustment lock nut on SuperFlow models must never be reused. While this is mentioned in the checklist, the significance of this requirement cannot be overstated: reusing the lock nut can cause the regulator to drift out of adjustment, leading to unpredictable breathing resistance during use.
Finally, the regulator must undergo a full functional test after reassembly, including fine‑tuning of breathing resistance and verification that the adjustment shaft moves freely and smoothly.