Assistance with natural gas installation

Jewelry Discussion
1

Hello all,

For anyone in the US who has natural gas piped in to your soldering
station, would you please help?

My studio is the downstairs of our house, the walk-out basement. We
have natural gas to the house and I have purchased a natural gas
mouth-blown torch from Fischer. This torch will not be used along
with bottled oxygen, only air that comes from my lungs.

The problem is that the plumber is ferklempt as to the pressure,
which is less than 1 PSI, but he had it firgured at 45 PSI after
trying to translate on-line the half-page literature that came with
the torch. He wasn’t privy to the European use of commas where we
use periods to designate decimals, which I only recently learned
too. I think we have the pressure correct but it seems the plumber
and the fellas at the supply house have no idea what goes between
the flex tubing in the wall and the torch. I’m even more in the
dark. They are convinced it is a regulator to amplify the pressure
to fill tires! I am thinking something more like a bunsen burner
set-up.

There is one guy named Thomas on another website for answering
questions about jewelry but the access to him is closed, and he has
natural gas. If Thomas or any other person in the US who has natural
gas at his or her bench could respond either on or off forum, it
would be greatly appreciated.

Thanks,
Nel Bringsjord
GIA Diamonds, AJP

2

My experience is that you need between 1 lb and 5 lbs of pressure to
conduct most bench soldering operations with natural gas (casting
will take up to about 10 lbs). To increase the pressure you should
check into a G-Tech gas booster. It’s a compressor that’s made to
solve this specific problem. You hook it up to your gas line, set
your gas regulator that you’ve attached to the front of the unit,
attach your hose to the flashback arrestor that you have attached to
the regulator and away you go. The flashback arrestor is critical
for your safety. The fittings are standard, 9/16 I think, but you can
check with Gas-Tech, they are an incredibly helpful company to work
with. I have two of their units at different locations and have been
very pleased. I don’t think you should use the natural gas straight
out of the line… Reason is that you will have no flashback arrestor
between your lit torch and your gas meter (possibility of
explosion). It takes a couple of pounds of pressure to push through
the arrestor, so you can’t use it unless you increase the pressure
from your gas utility somehow.

Mark P.

3

Hello Nel, Welding supply stores can sell you a one way valve that
will prevent flame from backing up the pipe and going boom; a sound
we all hate. That and a line valve and a fitting that will fit the
torch hose are all you need. Don’t worry about the line pressure.
It’s high enough for jewelry soldering jobs. Although at some point,
you might consider a small oxygen tank

Have fun. Tom Arnold

4

Nel,

I have built several workshops with natural gas at the bench. One
was in my basement; the latest has passed city inspection in St. Paul
Minnesota. Keep in mind few inspectors have any idea what the
regulations are in our field. The last time I did this I informed
them what to look for. The closest thing any inspector may have seen
is a dental lab.

The low pressure is standard and is not easily changed. It is
adequate in any case. More pressure would require the city to
increase or change the pressure regulator. This would then require a
whole system change including furnace, stove & hot water heater
modifications that would cost a fortune. Even in the college jewelry
lab where I teach there is only the lower pressure (about 1/2 psi)
for 2 casting torches and 36 work stations. I use the psi reference
even though the gas folks have different terms to describe just about
everything they are talking about. 1/2 psi has been used in the
traditional jewelry trade since the blow pipe was replaced in the
1950’s.

Contrary to many of our orchid experts, there is a low pressure
flashback arrestor that is available & necessary for any hook up. It
is designed to run the 1/2 psi flow of the natural gas. The arrestor
is from the SuperFlash Company and is Model #DGN. A pressure booster
is not necessary.

A quick release attachment should be installed for any natural gas
code set up. This looks the same as the ones air compressor lines
have to connect and disconnect air tools, only it is design for
natural gas or propane. The one I used is a Hanson 100-508 Gas-Mate
form Cleveland OH. This quick release is available at a RV supplier.
Make sure you indicate is for natural gas and not propane. Follow all
the flow direction arrows when installing. Anything hooked up after
this quick release is code (again in St. Paul MN). These fittings
after the quick release are also reverse direction thread as are any
of the fuel connections.

I rarely would show any inspector anything past this basic code
setup that follows:

From the natural gas blackpipe you need a gas ball valve (Home Depot
or any hardware store) for on/off. You can use either white Teflon
tape or the pipe goop that prevents leakage. Second is the quick
release gas connection and you are code, here anyway. The inspector
here indicated they did not need to see anything past this
connection. The flashback arrestor is attached next and specific to
our use with torches. From the arrestor your torch hose is the last
thing to complete the set up. A hose fitting (match your hose
diameter) is screwed into the arrestor and the hose end is crimped to
secure it. You simply turn off the ball valve when you are done at
night. Your installer should have a gas detector that will also show
any leakage. This should pass inspection. This setup passed
inspection as of 2007 at my shop.

Some blow pipes have a gas line that hooks up to the side of the
pipe. The only problem I see you facing is using this style blow pipe
and leaving the flame lit when not using it. The flame is burning at
the open pressure of 1/2 psi (a big flame). You will have to turn the
natural gas on and off each time you use it. Others pipes blow
through the natural gas or other fuel flame.

Many of us leave the torch on with the natural gas lit when not
soldering and add the oxygen when soldering. But we can regulate the
natural gas to a lower pilot light setting. Your desire to use a
blow pipe is admirable. I’ve done demonstrations with two different
styles, but always return to my Hoke jewelers torch for all but
melting. It does make a cool and totally historic demonstration, but
I trained on the Hoke and still prefer it. Teaching students
soldering with a blow pipe would be a different world too.

Give me a call if you need more info. 651-227-3921.

Best Regards,

Todd Hawkinson
Jewelry Instructor
Minneapolis Community & Technical College

5

Hi Todd,

Thanks for the comprehensive summation of natural gas installation.
Well done and appreciated.

I have heard conflicting opinions on the adequacy of “street
pressure” regarding direct hook -ups from house hold natural gas
lines. My welding shop maintains that a gas concentrator/ booster
such as G-Tech (mentioned in another post) is necessary. (Our
pressure here in Seattle is, I believe between 1/4-1/2psi.) The
boosters are a bit pricey, take up space and, of course, require
electricity.

Am I understanding correctly that there is indeed enough pressure,
in your experience, to hook directly into the natural gas supply
(adding valves, hose adaptors, arrestors, etc.)?

I plumbed my propane in years ago from a standard 20 lb/ 5 gallon
tank and use a ball valve to turn the gas off and on from inside my
studio… Have a similar system for casting.

I would love to run a natural gas line to the studio and eliminate
tanks, etc… I also get asked this question often when I teach and
talk about torches. Would love a more definitive answer to offer
them.

Thanks.
Andy

6

I have a few additional details to ad to the gas hook up comments I
made yesterday.

In my current location I have a commercial building and code for my
location may not be the same for everyone. I’m sure it is not. Use
my as a guideline. Again inspectors in various locations
have different positions on how to set up a torch system.

I had a good conversation with both tech support from Superflash as
well as Ed Howard from G-Tec. Both great resources with expertise.
The flashback arrestor I use may not work in a household setting. The
flashback arrestor I use actually engages at.8 psi. Gas pressure in
my current location is more than in residential areas. Superflash
may soon be developing a 1/2 psi flashback arrestor. We will wait and
see.

On Ed’s site he shows how the gas inspection in New Your City has
changed many if not all of the torch setup. I’m glad I live where I
do.

Believe me, safety is number one for any of the suggestions I give.

Another option for the gas is to use a one pound or under disposable
propane cylinder. This is code (here again) for indoor propane
usage. You would be surprised how long a small propane tank will
last. With this setup a regular flashback arrestor will work because
the pressure off this tank is enough to engage the inner spring of
the unit.

Looking at the original blowpipe issue, I would still ask if some
sort of regulator would be needed. With control of any gas for
blowpipe or torch there brings another batch of questions, options
and possibilities.

Regards,
Todd

7

Andy

You cannot get enough natural gas through your torch for jobs like
casting there is just not enough pressure to push the volume of gas
you need at residential delivery pressure which is 7-11 inches of
water or 1/4 - 1/2 psi. There is also a significant safety issue in
that check valves and flashback arrestors will not function at that
low a pressure. This means that it is fairly easy to set up a
situation where you can cause an explosion in your natural gas line
by forcing pressurized oxygen back down the gas line. This is really
a bad day if it happens. NYC has recently changed their safety rules
to require a NG pressure booster to deal with this problem after
several small (thank goodness) explosions in jewelers buildings
there. It is likely most states and municipalities will eventually
follow suit.

James Binnion
James Binnion Metal Arts

8

Andy, Jim Binnion answered(?) this question some time ago. I thought
his answer complete. I respect Todd’s experience and don’t want to
set off a battle of words.

I plumbed a gas line actually a plumber did it. The pressure is not
great enough for soldering. Soon I hope to have a G-Tec. I want
everyone to understand I, in no way, speak for JIm. Your gas pressure
may vary.

KPK

9

There is a little more to this than has been posted so far.

SuperFlash does not sell a flashback arrestor that works with low
pressure natural gas at this time. After reading Todd’s post I called
SuperFlash and asked their Sales Manager for the specific DGN model
(there are several in the series) that works with low pressure
natural gas and he said there isn’t one. They do have a flashback
arrestor that has A fittings that starts to crack at.85 psi but, as
with most other UL Listed flashback arrestors gas pressure needs to
be between 1-3 psi (it varies by manufacturer) to get a steady gas
flow to the torch. Whether they make one in the future or not remains
to be seen but there isn’t such a device at the moment.

The only device that reliably protects the gas meter in the event of
a flashback is a listed combination flashback arrestor check valve.
“Listed” as defined by the National Fire Protection Association
(NFPA) means tested and approved by a recognized organization such as
UL, CSA, etc.

I know this because a couple years ago the NYC gas utility hired an
Aurora, IL company that specializes in product failure analysis
Engineering Systems, Inc. http://www.esi-website.com/ to test check
valve and flashback arrestor devices to determine which ones were
effective in preventing torch flashbacks from blowing up gas meters.
In NYC several jewelers had exploded their gas meters and the problem
continues…the most recent being on 35th Street a couple months ago
(as well as a jeweler in NJ who blew up his meter in February).

ESI determined that only UL listed flashback arrestors worked all
the time and in each case the minimum cracking pressure was at least
1 psi, sometimes more. There are devices advertised as working with
low pressure natural gas but most often these are check valves or are
not UL listed.

Check valves are designed to keep high-pressure oxygen from flowing
into the natural gas pipe but they are not designed to handle the
5,000F flame of a flashback. When a flashback reaches a check valve
it most often melts and the flashback continues to the gas meter.

In NYC the Fire Code was changed to require listed combination
flashback arrestor checkvalves on torches connected to the gas pipe
but in every case they were found to block gas flow across the
variety of flashback arrestors that jewelers purchased. Interestingly
some claimed to have found flashback arrestor check valves that
worked with low pressure gas but upon investigation it was found that
they had bought the UL listed device then drilled it out, defeating
the protection capability, but to the Fire Inspector it looked OK.
You had to actually disconnect it to know it had been drilled.

So right now if you want to put a UL listed flashback arrestor on
your torch you need at least 1 psi to get good performance, perhaps
more pressure depending on the whose device you buy. In areas where
the gas infrastructure is older you may get only 1/4 psi (also
referred to as 7 inches water column) while in areas with newer gas
pipelines you may get as much as 2 psi. The only way to know for sure
is to install the flashback arrestor and see if your torch lights.

If you have low gas pressure then a G-TEC Torch Booster will supply
the pressure you need to make the flashback arrestor work
properly…we have many individual jewelers using our boosters as
well as schools such as Metalwerx, North Bennet Street School, George
Brown College in Toronto (135 benches) and we will be installing a
system for Fashion Institute of Technology (62 benches) in NY this
summer.

You can find out more about Torch Boosters here www.safe-t-gas.com
click on NYC Jewelers if you are in New York, everyone else should
click on Jewelry Manufacturing. Call or write if you have questions.

Ed Howard
G-TEC
1-800-451-8294

10 
I would love to run a natural gas line to the studio and eliminate
tanks, etc....

I believe it was Todd yesterday who laid out gas installation quite
well.= Other than the fact that you’re supposed to use yellow tape
(not white) , which is that little bit thicker, he said it quite
well. The really important thing to know is that it’s just plumbing.
People do it every day to put in stoves, dryers, water heaters.
There are things to know to do it properly and safely, but it’s not
rocket science. I’ve done it in my shop, in my home for a dryer, and
small commercial jobs, too. It’s just plumbing…

11

Nel

The Fischer mouth blown torch has a built in pilot light which
bypasses the control valve on the torch so you don’t need to light
it every time - I also use the pilot light as I would a spirit lamp
for melting setters wax etc.

Robin Key
Clavis Jewellery
Aberdeen, Scotland

12

Andy,

Back in 1995 I helped design & build the jewelry department at the
Minneapolis Community & Technical College. We moved from the second
floor (no venting) to the fifth floor (view, power, water, gas and
venting). The whole torch system runs on about 1/2 psi. This handles
two casting torches as well as 36 work stations with the Meco Midget
torches. We have never had a problem with pressure or the
non-operating of any of the torches. The natural gas is piped in
larger copper gas lines to give us more volume but no more pressure.
The copper pipe is even silver soldered and not tin/lead soldered
together from one junction to another (code here).

The Minneapolis city inspectors were ALL OVER this set up. It passed
and we still use the facilities almost everyday. In a public
institution you have to appreciate the college’s concern with
liability issues in this environment.

City gas street pressure is designed for furnace and hot water
heaters and is adequate for most jewelry making and repair. Platinum
is the exception. This is the same gas set up the jewelry industry
has had for many years. I have only built workshops in the cities of
Minneapolis and St. Paul Minnesota, eight of them over the years.

The oxygen pressure for the whole system is set at 20 psi. This in
our lab is for casting as well as bench work. We tried to move to
larger casting torches but we found that we had maxed out the natural
gas pressure. We have cast platinum for some demonstrations purposes
and used oxygen at 40 psi and propane at 5 psi on a separate system.

Everything works fine.

There are no flashback arrestors on the natural gas part of the
system. We have never had any problem in the 54 years the jewelry
department has been here in Minneapolis. The Old Jewelers Exchange
Building (long gone) had the same natural gas system design.

The recent assessment of this concern lies in the burning of fuel
backwards (flashback). This flame may burn backwards to a regulator
and consequent explosion. If a torch (natural gas/propane & oxygen)
is turned off wrong and pops, you have experienced flashback. As far
as I can tell, the NY jewelers when working on platinum have turned
up the oxygen pressure to the excess of 4o psi or higher. This
pressure would be enough to force the reverse flow of combustion if a
flashback would happen. Oxygen at 40 psi pressure could burn and
travel fast to the natural gas regulator and boom! Higher oxygen
pressure is the main reason of this current concern.

Torch pressure for oxygen need only be 4 or 5 lbs for most bench
work. This is the same for the Smith, Hoke and Meco torches. To my
knowledge, in my 38 years of jewelry making, with lower oxygen
pressure used for bench work, there has not been a flashback incident
in the Minneapolis/St.Paul area. Of course all it takes in one
explosion to have us all react.

My reference for much of my is also current. Bruce
Beuller, a specialist at Smith Torch is a system expert. Smith
Torch’s have long been an industry standard in jewelry making as well
as state of the art equipment in others industries as well. He may
have additional per individual set up.

If I set up shop in New York City we would have a whole different
conversation. I would probably just keep my mouth shut. Perhaps I
should have invited everyone to come and build a shop here.

Please, always be safe.

Regards,
Todd Hawkinson

13

James,

We currently use a Smith NE 150 torch for all the spin and vacuum
casting here in Minneapolis. They do not make this torch any more.
It melts and casts for both spin and vacuum casting. We can melt up
to 10 to 12 oz of alloy, sterling or gold with it. We run it on the
1/2 psi natural gas and 20 lbs oxygen. Any larger torch will not
work, so torch size makes a difference in gas pressure. These torches
which look just like the Meco Midget are a bit larger in size then
the Midget. We have spare parts for them considering we cannot buy
them any longer.

In my own shop I cast with a larger Smith torch and melt with
propane and oxygen. I use propane because the local gas supply in the
dead of winter gives us inconsistent quality in the natural gas. You
can tell this by the various flame colors that the torch produces in
sub zero weather. This usually follows with unexplained porosity in
some of the castings. The local supplier of gas fittings has also
confirmed that the natural gas varies because of the source at
certain times of year. City gas suppliers really are only concerned
about weather or not the gas will burn in your furnace.

I am in the process of designing another new jeweler’s workshop.
Even though the code is described as I have been detailing, I will
embrace all the safety concerns discussed in this topic. What I bring
to the design table is the historic setup evolving into the most
current safety requirements. I sure don’t want no blow ups around
here!!

Thanks to Ed Howard for all his

All my best safe regards,
Todd Hawkinson

14

Todd,

If I had natural gas available at my studio I would use it because
it is a safe, convenient source of fuel gas. And I would definitely
have a natural gas pressure booster to allow for larger torches for
casting and annealing and most importantly safety.

The issue is not whether you can set up a system to use natural gas
at 0.5 psi pressure to run a torch but whether you can do so safely.
I appreciate that as the designer of your colleges system you have a
certain amount of pride invested in it. I know that I would feel
that way about it if I were the one who had designed it. But if there
are no flashback arrestors on both legs of the system then it is not
a safe system.

James Binnion
James Binnion Metal Arts

15

Hello all,

I am the originator of this thread and must first say thank you to
all of you who have offered their advice.

Secondly, it must be clarified that I am planning on using a
mouth-blown torch, no oxygen involved, and the only thing that comes
out of me at high pressure…wait for it…is my sparkling wit. No
really, the torch is rated at .022 bar, which I understand to be
approximately 1/3 PSI. The torch is from Karl Fisher GmbH, in
Pforzheim, Germany. You can go to go
http://www.ldschmiedebedarf.de/product_info.php?products_id=7646

and it will show you the torch. It is product number 4876 E.

I chose the natural gas torch because we have the utility to the
house/studio, and as John said, it is already plumbed to many other
appliances that burn it as fuel so it seemed a natural fit. I chose
this particular model torch since placement and orientation of the
knob used to regulate the flow of gas through the torch seemed more
ergonimically suited for my small hands. This proved to be correct,
the movement is comfortable and intuitive.

This torch will only be for soldering gold and silver, and not for
casting. We do our casting outside, with our casting set up on the
back porch. We use Mapp gas for melting and it has been just fine
for over two years. It works well and since I am doing mostly
fabricating now, the expense is not an issue. I also use it for
melting metal for ingots.

My husband, Norman, is helping me research this and has determined
that= the gas pressure coming into most homes is 2 - 5 PSI. In fact,
the kitch= en stove seems to have no trouble making a really huge
flame on four burners and the large grill burner at the same time so
I think the pressure is enough. We are planning on having the gas
pressure measured, or getting the from the gas utility. I
would think they have the handy since we had to deal
with them three years ago when we had a whole house generator
installed (we live in Florida). Safety is of course of the utmost
concern.

I really feel more comfortable having a flashback arrestor and if
the PSI is at least 2, it should be no problem, don’t you think? I
am more concerned with having too much pressure. Oh, the pressure.

Again, thank you very much. My posts usually take a couple of days
to show in the digest, so I hope this info is not too tardy for the
thread.

Thanks,
Nel

16

From what I have read, I think the problem is the diameter of the
pipe. The larger the diameter the more gas (under the same pressure)
will come through. The type of flash arrester theat was used by the
Chicago Park District was a water trap. Most of these are not
available anymore as people always forgot to fill the water part.
When the water evaporated the gas would vent freely out ot the
building. It took no pressure for this type of flash arrester. I
never had a problem beacaused I turned the gas off each night and
checked the water level on Fridays. We ran 2 hoke torches for
soldering and a larger torch for casting. We didn’t have any
problems.

Good luck
Steve Ramsdell

17 
My husband, Norman, is helping me research this and has determined
that the gas pressure coming into most homes is 2 - 5 PSI.

He is missing a decimal point. The delivery pressure from the house
gas meter/ regulator is.2-.5 psi or 7-11 inches of water column. This
is the standard pressure all appliances like your stove and furnace
run on.

I really feel more comfortable having a flashback arrestor and if
the PSI is at least 2, it should be no problem, don't you think? I
am more concerned with having too much pressure. Oh, the pressure.

If it was 2psi that would make life so much easier for those who
want to run torches with flashback arrestors but unfortunately it is
only about a tenth of that

James Binnion
James Binnion Metal Arts

18

Steve,

Bruce Bueller of Smith Torch told me this was the answer also. I
will follow up on on this topic, because I AM designing a
new larger jewelry workshop and it WILL be safe and code. I plan on
working again with the city inspectors and will use all available
references and resources.

The answers to our shop safety should be available to even a small
one person shop.

Best Regards,
Todd Hawkinson

19

Todd,

But the bottom line is that Flashback arrestors will not work as
Designed at 1/2 PSI and any setup where a second gas is being
provided MUST have a flashback arrestor. Yes you can stick an
arrestor in the line and you may get gas to flow trough it but it
will not work as designed at lower pressures than the design
pressure. As such automatically any certification (CSA, UL, etc.)
becomes null and void.

Following your post I sent a email to find out what was up, and this
was the reply I received:

from Kurt Tarkany Global Sales manager at Superflash:

  The DGN unit he is referring to actually cracks at 1 PSI. We
  also have smaller CGA "A" size flashback arrestors that crack
  at about the same pressure with a tolerance range of.87 - 1.30
  PSI. I am not aware of a lower cracking pressure flashback
  arrestor anywhere in the world.

Also I should pointy out that while you may get through an
inspection by the local fire inspector, if there is a major loss and
the insurance company sends in their investigation team, you may well
be refused any compensation because of the lack of functioning
flashback arrestors.

Yes you may have had many years of successful use as you are set up,
just like the people at Pepcon in Henderson, Nevada… Until things
go wrong in a big way.

Kay

20 
just like the people at Pepcon in Henderson,

For those Orchidians that wonder what Pepcon was, take a look at
this video on YouTube:

Mike DeBurgh, GJG
Henderson, NV