Lately we get a lot of questions about unsafe regulator flex hoses. You might have seen some reports about hoses getting clogged and basically cutting of the air. In this article we will tell you how to check your hoses and to make sure you’r safe.
What is the problem?
Luckily scuba equipment failing or breaking down has become a rarity and we don’t see it that often anymore. So when something happens institutions like DAN are sure to look into the problem to determine what went wrong. One diver reported that despite his tank being full he experienced an out of air situation. After research the regulator seems to be fine and the attention shifted towards the hoses. When cut open large yellow crystals emerged which clogged the entire hose and essentially blocking the inlet of the second stage.
The outside of the hose looked pristine which made the case even more curious. After more research it became clear that through the heating and cooling of the hose, the inner layer transform into a wax like substances through the chemical proces called hydrolysis. The hose heats up on the surface when it’s placed in the sun and cools when the cooler breathing air is passing through it.
Polyether vs Polyester
After the incident more dive operators and divers called in their problems with braided hoses and the problem seems to be more wide spread than first assumed. The issue only seems to be with braided flex hoses and with one sort in particular. Hoses with a inner layer of polyester are the only ones affected. Hoses with a Polyether lining seem unaffected and are safe to use. Most of the cases also seems to be located in tropical area’s where the hose heats up enough to start the proces of hydrolysis. You need to be in tropical area’s for an extended period for crystals to form.
How to avoid unsafe regulator flex hoses
There are a few thins you can do to avoid these hoses and to make sure you dive safe:
- Like all other hoses braided hoses suffer from normal wear and tear. Even when hoses seem to be fine from the outside they still can have damage on the inside. All the hoses which gave problems where older than 5 years and some manufactures advice to change out hoses after 5 years.
- If you’r gonna buy a hose, always be sure that the inner lining is made out of polyether. If in doubt don’t buy the hose.
- When breathing out of your regulator gets more difficult or you have a indication it’s becoming more difficult. Inspect the regulator and when everything seems fine, suspect the hose.
- Test your own hoses! Go over the hose inch by inch pressing it. Any difference in resistance can be an indication of a problem with the hose.
- Check the inlet of your second stage. Crystals can clutter the inlet which leads to a out of air like situation.