Do you own an Intermediate Pressure Gauge?

[chris_b]

Any links on how to make/where to buy an IP gauge? Is adjusting the IP done easily with basic tools? And what exactly is "IP creeping?" Does it refer to pressure increasing, or decreasing? Over what time period (days, weeks, months) can this happen?

Sorry for all the questions, but I'm new and I'd love to learn more about this.

Chris

 

[The Chairman]

should be owned by every diver... Go get one!

As for rebuilds and IPs... thats a sore spot. Not enough shops cycle the regs enough (200-300 cylces) to get all of the O-Rings to seat. Lack of time and laziness contribute to this, so it is no wonder that many of us will recheck the IP before or after a dive to make sure that the IP is stable and where it should be. I check mine every other month or so, or IF the reg acts funny at all.

 

[BigDiver]

Listen to NetDoc and get the book Vance Harlow's guide to regulator maintenance.
It is great. Even if you have no interest in rebuilding your reg. it will give you some insight in to how a reg works and could save your life some day. Or on a lighter note you could save money.

 

[Stone]

Chris_B,

I have basic DIY IP gauge instructions on my website (URL below); however, I also own a "store-bought" gauge from Peter Built (Scubatools) that I really like. If you only want one to check the IP through your inflator hose, get the one called the "Techdiver IPG". It comes with the male quick disconnect of your choice for only $21.00 plus shipping.

As to your other questions: Creep is increasing pressure. It is a concern if it happens in seconds, minutes, or hours. The faster the creep, the greater the concern. You normally wouldn't leave a reg on a tank (with the valve open) for days, weeks, or months, so that timeframe isn't relevant. People do set up regs at the dock and take an hour or more to reach a dive site, so if the IP creeps from 140 psi to 160 psi in an hour, you would never know it unless you check (your first breath drops the IP back to 140). If the IP creeps from 140 psi to 160 psi in 10 minutes (and doesn't stabilize), something is going to give before you reach the dive site.

For the most part IP is set at the factory and adjusted (if necessary) during overhaul. Some regs allow you to adust IP externally (usually diaphram 1st stages), but most don't. Anyway, it's unlikely you can adjust away creep, so external adustment isn't important for most divers.

 

[ChrisF]

Originally posted by Iguana Don
Do you ever check th oil in your car/truck or do you just wait till 3000 miles and change it?

Well, when you put it that way.... I AM pretty anal about my car..... :ggrin:

I guess my question is, if my reg's IP was creeping up, wouldn't there be other more obvious symptoms (e.g. like tendancy to free flow at the surface) long before I experienced some kind of catestrophic failure? Why not just rely on those?

Certainly, if my regulator wasn't behaving normally, I'd take it in to get checked out.

I'm not trying to be a wise guy, just looking for information and trying to learn something here.

 

[Stone]

Originally posted by ChrisF
I guess my question is, if my reg's IP was creeping up, wouldn't there be other more obvious symptoms (e.g. like tendancy to free flow at the surface) long before I experienced some kind of catestrophic failure? Why not just rely on those?

ChrisF,

To use another tire inflation analogy: If you wait until you see a symptom (uneven tread wear), the damage is already done.

The failure mode depends on the type of regulator (both stages). A downstream unbalanced second may just start freeflowing when the IP reaches a certain pressure. A balanced second may never show a symptom until something blows.

 

[Rooster]

Yes I own one,but I'm a certified US Divers (Aqualung) Tech and service my own gear

 

[padiscubapro]

Originally posted by chris_b
Any links on how to make/where to buy an IP gauge? Is adjusting the IP done easily with basic tools? And what exactly is "IP creeping?" Does it refer to pressure increasing, or decreasing? Over what time period (days, weeks, months) can this happen?

Sorry for all the questions, but I'm new and I'd love to learn more about this.

Chris

When someone is talking aboat IP creep it happens over a relatively short period (with a guage its often visible within seconds) of time and creeps upward.. many people never notice this because they are breathing off their regs constantly so the slight buildup of pressure until the next inhale isn't noticeable..
most regs will bleed air out the second stage once the IP gets above a certain pressure. This can be a big problem on a stage or pony bottle.. What good is a redundant air source if its not there..

This is the main reason why you should put an overpressure relief valve on a first stage thats used exclusively for drysuit inflation.. if the pressure kept rising eventually it would overcome the addition valve and force a big burst of gas into your drysuit.

It only adds a few seconds to you pre dive safety check and can stop a potential accident..

go to the following web site
http://www.scubatools.com/Gauge.html

look at either the dive master guages or the tech diver guages.

 

[padiscubapro]

Originally posted by ChrisF


Well, when you put it that way.... I AM pretty anal about my car..... :ggrin:

I guess my question is, if my reg's IP was creeping up, wouldn't there be other more obvious symptoms (e.g. like tendancy to free flow at the surface) long before I experienced some kind of catestrophic failure? Why not just rely on those?

Certainly, if my regulator wasn't behaving normally, I'd take it in to get checked out.

I'm not trying to be a wise guy, just looking for information and trying to learn something here.

If the IP is high, the reg does tend to free flow, If the reg is creeping fast it will be noticeable, but a slow creep may never show symptoms until it finally fails..

 

[The Chairman]

Originally posted by padiscubapro
but a slow creep may never

catch up to me... :tease: