DiveGearExpress
Contributor
It is NOT common practice for local dive shops in the US to replace PRDs (burst disks) in valves when cylinders are hydrostatically tested, unless the customer specifically requests and pays additionally for "valve service" with the hydro. Typical cost of valve service (i.e. the valve is disassembled, cleaned, soft parts and PRD replaced, lubricated and reassembled) in the US local dive shops varies but $20 to $25 is commonplace. Scuba valve PRD replacement only varies but $10 to $15 is customary.
RE: The multiple burst discs that all failed in the same hotel after filling at the same dive shop a few hours earlier... it was NOT the temperature of the hotel room, it was not the dive shop, and it was NOT coincidence. It was because the burst disks had reached end-of-life, the typical circumstance is that burst disks fail during (or more likely shortly after) the tank is filled. It is simply reasonable to expect that two burst disks, exposed to similar conditions of handling over many years would both fail at essentially the same number of duty cycles (plus or minus a few fills.)
Aging or improperly installed burst disks in SCUBA cylinder valves are a hazard to individuals and to property; failing to periodically service your scuba valves is dangerous.
Divers can replace the burst disks of their valves themselves if they wish, although it's not cost effective vs the LDS for most people unless you own more than a single digit number of tanks. Light duty inch-pound torque wrenches go for about $35 to $40 on Amazon. One piece PRD safety assemblies vary in cost between $5 and $10 each depending on the type, source and quantity. You might want a transfill whip, if so they go for around $100 to $150. A few minutes of your time with YouTube plus one or two disks sacrificed to learning curve, and "Bob's your uncle." Considerably less if you use an ordinary socket wrench and a "penny"
RE: The multiple burst discs that all failed in the same hotel after filling at the same dive shop a few hours earlier... it was NOT the temperature of the hotel room, it was not the dive shop, and it was NOT coincidence. It was because the burst disks had reached end-of-life, the typical circumstance is that burst disks fail during (or more likely shortly after) the tank is filled. It is simply reasonable to expect that two burst disks, exposed to similar conditions of handling over many years would both fail at essentially the same number of duty cycles (plus or minus a few fills.)
Aging or improperly installed burst disks in SCUBA cylinder valves are a hazard to individuals and to property; failing to periodically service your scuba valves is dangerous.
Divers can replace the burst disks of their valves themselves if they wish, although it's not cost effective vs the LDS for most people unless you own more than a single digit number of tanks. Light duty inch-pound torque wrenches go for about $35 to $40 on Amazon. One piece PRD safety assemblies vary in cost between $5 and $10 each depending on the type, source and quantity. You might want a transfill whip, if so they go for around $100 to $150. A few minutes of your time with YouTube plus one or two disks sacrificed to learning curve, and "Bob's your uncle." Considerably less if you use an ordinary socket wrench and a "penny"
