Pipe sizing, fittings?

brusician

I am just a diy'r. I am trying to properly size the gas piping for my house, I am redoing most of it for various reasons. Largely because local codes make plumbers get special gas permits, and they then charge accordingly... Anyway, I have looked through many forums on pipe sizing, read codes and guidelines and feel like I understand how to size for length and demand. What I am confused about is how to account for length equivalency of fittings especially T's with multiple output Internal diameters. For instance if I have a T that is 1" in with a 3/4" out and a 1" out is it a 1" T Leq or something else?

Brewbeer

I'm also a DIY'er of decent skill. I do water and hydronic piping, and basic 120/240 volt wiring in my home. I have sized gas lines for appliance loads, but I will NOT touch the gas lines in my house. IMO, gas line work needs to be left to pros who have proper insurance.

Do the sizing calcs, and do what ever drilling of holes/removal of finish surfaces/whatever prep work is needed to run the lines in the locations you want them. But once that's done, hire the licensed, insured professional to install the lines, and make sure they pull a permit. There's too much a stake with gas not to.

Jamie Hall

Gas has this annoying habit of going boom when there are small leaks -- which may not be noticed (don't count on smelling it before launch). Like @Brewbeer , I do almost all the work on the place I care for. But gas piping? No. That's where I stop. Please hire a pro. Yes, you pay for it, but it's a lot cheaper than blowing yourself and your family up.

NY_Rob

DIY gas piping work sounds like a really risky endeavor.
I'm also a big DIY'er, but like Brewbeer above- I also draw the line at gas piping. I literally don't think I could sleep at night if I did my own gas piping.

One of the reasons your local plumbers charge so much because of the training and insurance required to service gas lines.

Leon82

Give your self some cushion using the pipe chart for length if your worried.

A spray bottle with soapy water will help find any leaks if you're dead set on doing the piping

ChrisJ

I'll be honest.
I ran all of my own gas piping because I don't trust most others because as previously said, it goes boom.

As @Leon82 said, I sized as per the load and went bigger than necessary in case I make changes down the road.

According to @Hatterasguy I went way bigger than necessary, but it worked out because I want to run a 4KW generator off of the same line that feeds my Weber Grill.

Run the piping, and pressure test it. Mine was all tested at 40 PSI with the valves to the appliances turned off for several weeks. The reason for weeks, was that's how long it took them to run the gas in from the road. If it held 40 PSI for 24 hours I'd be happy.

I've ran threaded pipe that has no problem holding 140 PSI from an air compressor.


If all of your joints are tightened properly, and all of the piping is run per code and pressure tested it should be safe. If permits are necessary, you should pull them. Do the right thing. All of my piping was done with permits pulled and inspected by the state.

jonny88

What does "charge so much mean".What are you comparing it to out of curiosity.

Firecontrol933

A house blows up and the first thing the fire investigators and the insurance investigators for you and all of your neighbors look at is the fuel supply to the house. Who has ever worked on it, were the applicable permits pulled and is there a record of any leak checks having been done..... signed by someone skilled and/or licensed to do the work.

That same skilled and licensed professional will have millions of dollars worth of liability insurance to cover themselves, you, your family, your home, your neighbors families and homes and to fight the gas company's lawyers when Murphy's Law steps in.

ChrisJ

Hatterasguy said:

jonny88 said:

What does "charge so much mean".What are you comparing it to out of curiosity.

$20.00/hr for the CL handymen.

Went to the dentist on Friday for one filling and one additional filling into an existing root canal to seal it. About 40 minutes total time.

$754/hr.

Can you do teeth in addition to plumbing?

Let's not forget their insurance and cost to operate is probably far higher than a plumber.

However yeah..........for a long time I thought root canals were physically painful. No, it's when you need to pay for it that it hurts.

brusician

To assuage any fears, I already have a permit, and have spent a fair amount of my life around industrial construction and machines. I have done some gas work in the past, I have just never had to design for this number of 'T's and elbows. Mainly I came across the 'non-adapted addendum' to the Portland gas code involving fitting equivalencies and wanted to know if it had any bearing in the real world or if just running with the IFGC guidelines with some padding is adequate. I don't live in Portland.
P.S.- I was told by a plumber I know to DIY this, that is where I learned of the special gas plumber permitting requirements.
...I wish I could think of something clever to say about DIY root canals...Thanks guys!

ChrisJ

Hatterasguy said:

brusician said:

Mainly I came across the 'non-adapted addendum' to the Portland gas code involving fitting equivalencies and wanted to know if it had any bearing in the real world or if just running with the IFGC guidelines with some padding is adequate.

The code was adapted to prevent a drop in pressure of more than, IIRC, .50" water to any appliance.

That's insignificant if the appliance requires 3.5" and the utility is providing 7".

If you were to reduce all your piping by one size............3/4" to 1/2"...........as an example, the pressure drop would increase to about 1.0" water. All the appliances still work fine but you're way below the "code" requirements.

There are designers on here that have used 3/8" iron pipe for all gas lines in a residence. The pressure drop with all of them running was about 2". With a building supply of 7", it still works perfectly fine. The fellow who did it is a sharp guy and saved a fortune on iron pipe and fittings without any downside.

The only time you get into any trouble is if the utility is providing 5" and you push the envelope.

From what I've observed this is a bad assumption.
My regulator is set at 6" WC at the meter, but it's only 6" WC when you're using little gas, as you start sucking fuel down that pressure drops by nature of how the regulator works.

Going by memory, I believe we saw it drop about 1" when the boiler fired and WH was running. This will increase when the stove, dryer, grill etc are on.

2" of drop, would be totally unacceptable here and I'm told all houses in my area get 6" WC.

According to the gas co, my meter's pressure regulator is fed with 50 PSI via a 1/2" plastic connection.

brusician

Okay, I have done it a few ways now and have a plan drawn up that should work. Thanks again for all the info, I feel more confident in my decision.

ChrisJ

Hatterasguy said:

brusician said:

2" of drop, would be totally unacceptable here and I'm told all houses in my area get 6" WC.

If you started with 6" and dropped to 4" and the appliances are fine with 3.5", I fail to see why it would be unacceptable.

Now, if you have a generator that requires 6", that's a different issue.

Not sure why you quoted brusician when I said it?
An appliance running at 3.5" requires 4.5" at the input of the regulator.

6 - 2 = 4.
And this is still wrong, because as I said, that pressure drops as your load increases due to how the high pressure regulator works.

So, 5 - 2 = 3.

3" input to a regulator that requires 4.5" is obviously unacceptable. Now my manifold that calls for 3.5" is running at 2" - 2.5" because someone didn't follow a simple piping chart.

That's my feelings on the subject based on my own personal experiences. It may work in a lot of areas where the meter isn't fed with high pressure, but it doesn't work on a system like mine.

Charlie from wmass

We have and use the .6 inch drop.chart for areas with good supply pressure and .3 inch for areas with low supply pressures. I do not have have calls for starving appliances when the main pressure is low in February.

Charlie from wmass

I use the charts as required by my inspectors as is relevant to the local gas mains. Certain areas in the Boston area have 1 1/4 Supplies from the main. Also areas of Northampton, Pittsfield, Westfield, Springfield, MA all require the .3 inch drop. I experienced pressure as low as 3.8 inches this February in these areas during peak demand. My systems kept up with the heat and domestic water loads. Piping not done by me saw many boilers only with enough gas to keep the buildings at 62. Oh and I had 3 calls from Worcester .
If you are not able to thread the proper size pipe, you can always use the CSST. They make that up to 1 1/2" If you find it too difficult to work with the threader.

Charlie from wmass

It was 3.8 with 0 draw. That dropped to 3.5 when the appliances ran.

Charlie from wmass

Yes they ran at their rated minimum pressure.

ratio

My experience is similar, on systems sized for maximum pressure drop I generally run into problems, on systems sized with minimum pressure drop I generally don't. Do yourself a favor & do what the Old Guys did, size it for minimum pressure drop using the old tables. Sure, you could do the job cheaper if you sized the pipes for a greater pressure drop, & it'll even work right some of the time. But that system is sensitive to any issues that might come up, such as a sagging inlet pressure, unreamed pipe, updated appliances that are more fashionable & just happen to be larger, new appliances, whatever. All those can be taken into account, by ... sizing the gas line for less pressure drop. Right back where we started.
My biggest concern is that there is a pretty large window between burning properly & can't light off, anywhere in there we could possibly be pumping out CO, sooting things up, and/or condensing in a major way, without much indication. I'm sensitive to this because I'm the startup guy & it's my job to bless the new installs with a warranty, which I will not do if the gas pressure isn't within the mfgr's specs throughout the range of the connected load, i.e. none through all other appliances firing. Easier & cheaper to to it right the first time.

nicholas bonham-carter

Back to the root canal analogy, the specialist must be charging what the market will bear. Spend an hour in the dentist's chair, and you will pay 7-8 Jacksons; but take a cruise in the root canal gondolier's chair, and the cost is 6 times that. Both people are skilled, well equipped with specialized equipment, and continuingly educated/trained. The liability insurance risk must be about the same.
Restrictive trade practice, or no?--NBC

ChrisJ

nicholas bonham-carter said:

Back to the root canal analogy, the specialist must be charging what the market will bear. Spend an hour in the dentist's chair, and you will pay 7-8 Jacksons; but take a cruise in the root canal gondolier's chair, and the cost is 6 times that. Both people are skilled, well equipped with specialized equipment, and continuingly educated/trained. The liability insurance risk must be about the same.
Restrictive trade practice, or no?--NBC

Not everyone can afford what the market will bear.
Even when it comes to things such as food, housing and medicine.

Others are more than capable to do things on their own, often better than what can be hired so why wouldn't they do it?

Charlie from wmass

The true professional charges a fair price that covers the cost of doing business and provides an adequate wage to live on and save for retirement. The fool worries about what the market wants to pay, as the market always wants to pay less unless they are buying an item they can flash to their neigjbors, family, and friends.

ChrisJ

Charlie from wmass said:

The true professional charges a fair price that covers the cost of doing business and provides an adequate wage to live on and save for retirement. The fool worries about what the market wants to pay, as the market always wants to pay less unless they are buying an item they can flash to their neigjbors, family, and friends.

Yeah,
Kinda like you can never work fast enough for your employer.

Charlie from wmass

I know I can never work fast enough for my boss. Lol

Charlie from wmass

He says no raise for me.

ChrisJ

Doctors can help you with that problem, I hear it's common at your ages.

KC_Jones

My boss is retiring, he said I can have all the money I want after he is gone....