# Med Gas question



## markb (Jun 11, 2009)

4.

Where is the in-line high pressure sensor for a medical gas system located?











A.

At the manifold.



B.

Upstream of the pressure regulator.



C.

Upstream of the main shut-off valve.



D.

Downstream of the pressure regulator.

?


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## Ron (Jun 12, 2008)

Looks like a test, asking it like a test question.

Are you asking us to help you on your test. :laughing:


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## mongo (Jun 26, 2010)

D. Although the exact wording is thus:



*5.1.9.3* The Alarm indication required in 5.1.9.2.4(7) and 5.1.9.2.4(8) shall originate from sensors installed in the main lines immediately downstream (on the patient or use side)of the source valve. Where it is necessary to install a main line valve in addition to a source valve _(see 5.1.4.5)_, the sensors shall be located downstream (on the patient or use side)of the main valve. 

NFPA 99C 2005 edition.



Area alarm panel sensors shall be on the patient side of the zone valve box.


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## Tommy plumber (Feb 19, 2010)

NFPA 99 2005 edition states at 5.1.8.2.2 "Pressure/vacuum indicators shall be provided at the following locations, as a minimum:

(1) Adjacent to the alarm-initiating device for source main line pressure and vacuum alarms in the master alarm system
(2) At or in area alarm panels to indicate the pressure/vacuum at the alarm activating device for each system that is monitored by the panel
(3) On the station outlet/inlet side of zone valves."


So there is a line pressure indicator after source or main valve, and immediately after zone valve.


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## mongo (Jun 26, 2010)

Tommy plumber said:


> NFPA 99 2005 edition states at 5.1.8.2.2 "Pressure/vacuum indicators shall be provided at the following locations, as a minimum:
> 
> (1) Adjacent to the alarm-initiating device for source main line pressure and vacuum alarms in the master alarm system
> (2) At or in area alarm panels to indicate the pressure/vacuum at the alarm activating device for each system that is monitored by the panel
> ...


Indicators are *GAUGES.*
Different from *sensors (switches).*
See *5.1.8.1.2*


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## Tommy plumber (Feb 19, 2010)

Thank you. I stand corrected.


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## markb (Jun 11, 2009)

mongo said:


> D. Although the exact wording is thus:
> 
> 
> 
> ...


Yes, test question. Preparation for my CofQ. Around here MedGas has its own certification and training, but the Government still requires you to understand the basic concepts and codes as an entry-level journeyman. 

Thanks for the help. I just didn't know if MedGas systems used whole-system pressure regulators or if the pressure was adjusted on a per-unit basis or something along those lines. Thus, was unsure of D.


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## mongo (Jun 26, 2010)

markb said:


> Yes, test question. Preparation for my CofQ. Around here MedGas has its own certification and training, but the Government still requires you to understand the basic concepts and codes as an entry-level journeyman.
> 
> Thanks for the help. I just didn't know if MedGas systems used whole-system pressure regulators or if the pressure was adjusted on a per-unit basis or something along those lines. Thus, was unsure of D.


If Canada uses NFPA 99C as the standard, it will be the same as the USA except for label color scheme. Final line regulators are also located at the source, downstream of the filter.


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## Tommy plumber (Feb 19, 2010)

Hey Mongo, I have a question. With regard to the sizing of med gas lines, the only thing I can fine in NFPA 99 is that it says 'minimum flow shall be availble at station outlet/inlet.' Where is sizing info for large runs? If I were to receive prints to size out a large health care facility, let's say with 250 beds, I'd have to contact a med gas engineering firm to size out all the main runs. Where is this info available,any idea? -Tom Only thing I have found is the California plumbing code, but it's pretty limited.


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## mongo (Jun 26, 2010)

Tommy plumber said:


> Hey Mongo, I have a question. With regard to the sizing of med gas lines, the only thing I can fine in NFPA 99 is that it says 'minimum flow shall be availble at station outlet/inlet.' Where is sizing info for large runs? If I were to receive prints to size out a large health care facility, let's say with 250 beds, I'd have to contact a med gas engineering firm to size out all the main runs. Where is this info available,any idea? -Tom Only thing I have found is the California plumbing code, but it's pretty limited.


I use an engineered spreadsheet on positive gases (oxygen, medical air, nitrous oxide, nitrogen, insrument air,etc.).

Vacuum systems are a little different (minimum size on any pipe is 3/4"). It is also a separate spreadsheet.


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## markb (Jun 11, 2009)

mongo said:


> If Canada uses NFPA 99C as the standard, it will be the same as the USA except for label color scheme. Final line regulators are also located at the source, downstream of the filter.


So, therefore, there is a pressure regulator downstream of the source valve AND at each unit?


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## mongo (Jun 26, 2010)

markb said:


> So, therefore, there is a pressure regulator downstream of the source valve AND at each unit?


 
Not so. 
I'll make you a schrmatic and post it.


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## markb (Jun 11, 2009)

Thanks Mongo :thumbup:


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