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An issue for you to ponder
First, an article on the Matheson-TriGas website, titled "Introduction to
Regulators". Thanks to Andy Galassi for posting the Matheson regulators on
ebay, which steered me to this site.
Note the third paragraph;
"On occasion, an outlet valve is affixed to the outlet port of the
regulator. This valve is to be used to shut the regulator on or off for
brief periods of time. It should never be used to throttle or control the
flow of gas emitted from a regulator. This practice could cause serious
damage to both the regulator and its operator. Flow should always be
controlled by some other piece of equipment such as a rotameter or mass
Next, a brief introduction to one method of risk analysis. Factoring the
likelihood of an event occurrence, with the severity of that occurrence,
yields a risk factor. In other words, an event with very severe
consequences actually has relatively low risk if the likelihood of it ever
happening is nearly nil. On the other hand, an occurrence with only
slightly severe consequences may have a greater risk factor if the
likelihood is very high. For example; Getting hit by a meteor falling from
the sky has very severe consequences, but the likelihood is so miniscule,
no one (at least that I know), worries or even thinks about it. The
potential consequences of being involved in a serious automobile accident
are every bit as severe (dead is dead), but the likelihood is orders of
magnitude higher, thus the installation of seatbelts and airbags into
modern automobiles (Let's not pursue the political issues involved in
mandatory seat belt laws here. That is a topic for another list).
Now for my concern. I just recently installed a needle valve rated at 6000#
onto the outlet port of the dual stage CO2 regulator. I know this valve is
way overrated for this service, but it was FREE. To the outlet side of the
valve, a length of standard aquarium airline tubing was connected via
another fitting. This allows for a very controllable system.
The previous configuration consisted of an adapter fitting that screwed
into the regulator, to which a short length of standard airline tubing
connected. At the end of this tubing, a standard aquarium air valve was
installed just upstream of the CO2 reactor. While this may not rise to the
standards of some subscribers to the digest, it performed well for me. I
installed the high pressure valve because it was there...
I am beginning to believe I should remove the high pressure needle valve
and revert to the previous configuration. My concern is that if the
regulator does malfunction, it may present the low pressure (outlet) side
of the regulator with pressure in excess of it's design rating, resulting
in rapid, uncontrolled disassembly of the regulator (big bang theory?).
While the likelihood of this occurring is very low while someone (me) is in
the damage field, the consequences, if it happens, are potentially very
While I must stop short of insisting everyone subscribing to the list
should remove the valve from the outlet port of their regulator, one of the
voices in my head insisted I bring this thought to your attention.
Your humble servant,
Douglas Guynn, in west Texas, where the sky is clear, the wind is cold and
dry, and the water, what little there is, is REALLY hard.
dguynn at nwol_net
Veritas Vos Liberabit
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"The tree of liberty must be refreshed from time to time with the blood of
patriots and tyrants. ... Resistance to tyrants is obedience to God."
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." --Benjamin Franklin
"If you love wealth better than liberty, the tranquillity of servitude
better than the animating contest of freedom, go home from us in peace. We
ask not your counsels or arms [and] may posterity forget that ye were our
countrymen." --Samuel Adams
"Almighty God...give me liberty or give me death!" -- Patrick Henry
It is not a stunned silence that the world hears. It is the quiet
meditation of a warrior.