Since April 1999 KMDSI has inscribed every SuperLite® 17A/B, MK21 neck clamp assembly P/N 505-055 with date of manufacture and identification number. KMDSI date stamps neck clamp assemblies so users will be able to determine how long they have been in service.
April 2009 is 10 years since the inception of the inscribed neck clamps. If your neck clamp is dated before April 2004 it is older than five years and KMDSI strongly recommends that the neck clamp be inspected IAW (In Accordance With) the A2.2 (Monthly Inspection) on a weekly basis.
Regardless of age, ALL neck clamps should be inspected before every dive IAW A2.3 daily set up checklist section 1.1.
If your neck clamp is not inscribed, it is older than 10 years and KMDSI strongly recommends that the neck clamp be replaced or be inspected IAW the above recommendation.
Experience has shown that clamps used in saltwater are more subject to crevice corrosion than those used in fresh water.
Any Neck Clamp that does not pass inspection should be removed from service and destroyed so that there is no chance of it being used by accident or negligence. The appropriate annotations should be logged into the helmets maintenance log book.
All metal parts should be inspected for cracks or corrosion and replaced immediately if this type of dam- age is found. While some surface rust or corrosion is to be expected, severe corrosion can lead to the SL 17 A/B & MK 21 Neck clamp assembly eventual failure of the part. When performing the A2.2 special attention should be directed to the portion of the adjustment stud that is inside the block.
KMDSI strongly recommends that the Chin & Yoke strap kit P/N 525-234 be used with all SL-17 A/B and MK-21 helmets. In event of a neck clamp failure these retaining systems should keep the helmet in place. It is strongly recommended that the latch catch safety pin P/N 535-900 always be used.