What size propane line for generator: super helpful guide

What Size Propane Line For Generator? [Question Answered]

Most generators use liquefied propane gas to power up different appliances. That’s why the gas lines must be sized properly. Because otherwise, all the appliances won’t be running smoothly at all times. 

So, you may wonder, what size propane line for the generator

The proper size propane line for generator depends on the total energy load. It also depends on the material of the pipe. The wider the pipe the more energy it’ll deliver. But the length of the pipe will reduce the energy load rating. Simply, calculate your total energy and then match it with a chart. 

But this brief overview doesn’t cover everything. That’s why we’ve elaborated further on this matter. 

Keep reading if you want to know more about propane lines for generators

Running A Size Propane Line For Generators: Things You Need To Know First

The pressure of liquified propane and natural gas aren’t exactly the same. That’s why you’ll have to calculate the correct propane line size for generators. sizing properly. 

Otherwise, the generator will automatically fail to deliver enough energy to the appliances. 

On top of that, the material used to make the pipe also matters a lot. The most common material used is either steel or copper. 

Based on the material, your calculations will be different. 

Because of that, you’ll need to know about both types of pipes. Luckily, we’ve done the calculations for you! 

It’s the same as comparing type 1 and type 27 cutting wheels. The capacity of steel and copper pipes may seem similar at first. But they aren’t totally the same. 

But before that, you’ll need to know how much energy you’re going to use. It can easily be calculated by adding all the appliances. 

If you’re going to add some appliances in the future, consider them as well. Because it’s better to sort this sizing problem once and for all. 

The total energy is calculated using BTU as a unit. Simply put, the more appliances you have, the higher the BTU requirement will be. 

To help you out, we’ve prepared a model scenario for you-

Appliances Average BTU Per Hour (Approx.)
Refrigerator 3000
Water Heater285000
Gas Logs30000
Gas Lights2500
Microwave 25000
Total 380500

This is only an example of the possible energy cost. This will vary depending on the appliances that you’re going to use. 

Running some important appliances like refrigerators will require less energy. But water heaters or microwaves require a lot of energy. 

So, calculate ahead of time how much energy you really require. This also applies to the propane lines for portable generators

On that note, you’ll also have to consider propane line fittings and regulators. Regulators help keep the gas distribution stable. 

Sizing A Propane Gas Line For Generators

Now that we’ve discussed this, it’s time to choose the pipes. Your total generator capacity has to be more than the required BTU. That’s pretty self-explanatory. 

But what size should you choose? 

Sizing a propane line depends on the material and the width of the pipe. The wider it is, the more energy load it will be able to withstand. 

You’ll also have to adjust the total pipe length. Because extra length will decrease the energy load. 

Luckily, for you, we’ve made a propane line size chart for you. We’ll cover the copper pipes first. We’ll talk about the steel pipes afterward. 

Like CRV and S2 Steel, they share a lot of similarities. But this will point out the dissimilarities too. 

Here’s what you’re looking for –

Copper Pipe Size Pipe Length (10 ft)Pipe Length (20 ft)Pipe Length (40 ft)Pipe Length (80 ft)
¼ Inch35000 BTU/hr25000 BTU/hr17000 BTU/hr12000 BTU/hr
⅜ Inch75000BTU/hr50000 BTU/hr35000 BTU/hr25000BTU/hr
½ Inch150000 BTU/hr105000 BTU/hr70000 BTU/hr50000BTU/hr
⅝ Inch265000 BTU/hr180000 BTU/hr125000 BTU/hr85000BTU/hr
¾ Inch380000 BTU/hr260000 BTU/hr180000 BTU/hr120000BTU/hr
1 Inch805000 BTU/hr555000 BTU/hr380000 BTU/hr260000BTU/hr
1 ¼ Inch1450000 BTU/hr995000 BTU/hr685000 BTU/hr470000BTU/hr

As you can see, the total BTU load increases based on width and length. If you’re going to use copper pipes, these are your numbers. 

Simply calculate your total BTU per hour and match it. Choose a size that has a higher BTU/hr rating. That way you can easily avoid any potential risks. 

For example, if your energy load is 330000 BTU/hr, you’ll have to pick a ¾ inch copper pipe. But your choice is limited to only 10 ft as it has a 380000 BTU/hr rating. The rest do not. 

If you need more length, you’ll have to increase the size. Only 1 Inch copper pipe can handle 330000 BTU/hr. So, your perfect pick is the 1-inch copper pipe for 20 ft. in length. 

Alright, it’s time to talk about the steel pipes. The factors behind this calculation remain the same. 

For that, we’ve made you a small chart- 

Steel Pipe SizePipe Length (10 ft)Pipe Length (20 ft)Pipe Length (40 ft)Pipe Length (80 ft)
½ (⅜) Inch235000 BTU/hr160000 BTU/hr110000 BTU/hr75000BTU/hr
¾ Inch490000 BTU/hr340000 BTU/hr230000 BTU/hr160000 BTU/hr
1 Inch925000 BTU/hr640000 BTU/hr440000 BTU/hr300000 BTU/hr
1 ¼ Inch1900000 BTU/hr1305000 BTU/hr900000 BTU/hr620000 BTU/hr
1 ½ Inch2850000 BTU/hr1960000 BTU/hr1345000 BTU/hr925000 BTU/hr
2 Inch5490000 BTU/hr3770000 BTU/hr2590000 BTU/hr1780000 BTU/hr
2 ½ Inch8740000 BTU/hr6010000 BTU/hr4130000 BTU/hr2840000 BTU/hr

These are the energy loads of the steel pipes. Clearly, you can notice that they’re way better than copper ones. Copper pipes are mostly used in households. 

But installing a propane line for the generator is super risky for amateurs. That’s why it’s best to hire professionals to do it for you.


How long will 100 pounds of propane run a generator?

The answer depends on the generator. For example, 100 pounds of propane can run a 7 kW generator for about 64 to 67 hours. But if you use a 12 kW generator, it will last only 32-36 hours. But don’t take these numbers for granted because they will vary. Because efficiency is also a key factor. 

How far can the generator be from propane?

A generator can be 10 ft away or 100 ft away from the propane source. There are no correct answers. The minimum distance between the two is 10 ft. The distance must be maintained to avoid any fire hazard due to ignition reasons. But the further a generator is, the wider the pipe has to be. 

How long will a 120-gallon propane tank run a generator?

120-gallon propane tanks are perfect choices for many homeowners. A tank of that size can easily run a generator for 1-2 days. If you want to use the generator for longer, you’ll need a bigger tank. A 500-gallon tank can run a house for 7-8 days. Remember that these numbers are based on 50% load. 

Final Thoughts

That was everything we could gather on what size propane line for the generator. Hopefully, this information was enough to clear your confusion. 

If you want a detailed answer, you should call the nearest service. This way you can hire someone to thoroughly spectate your house and appliances. For a super accurate result, this is the best choice. 

Finally, have a nice day and have fun!

1 thought on “What Size Propane Line For Generator? [Question Answered]”

  1. Pingback: How Much Propane Does a 20kw Generator Use Per Hour? - Generator Advice

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