Expert: Henry P. Babcock - 4/2/2009

Question
Hi, I would like to know about possible failures of first stage. What kind of possible failures may occur? Is free flow from first stage possible?
Thanks & regards

Answer
Hakan,

Yes, failure of the first stage resulting in free flow is possible.  Some of the causes could include:

The intermediate pressure adjustment may creep higher than manufacturer’s specifications

Foreign matter or sand interfering with the HP seat

Disintegration of HP seat materials

HP seat dirty, damaged, or worn

Crown orifice dirty, damaged, or worn

Failure of internal o-ring(s)

Freeze up due to extreme cold water

Most of these problems can be avoided by proper rinsing and maintenance between dives and regular servicing by an authorized service technician.  In the case of extreme cold water problems, use a regulator specifically designed for cold water.

Hope this helps,

Henry Babcock
AllExperts SCUBA Expert