Gas Riser Diagram

Gas Riser Diagram – The Pipes Must Be Sized Correctly

A gas riser diagram is a three-dimensional drawing showing gas lines that will supply gas to gas-burning appliances in a home or commercial building. The pipes supplying the gas to each appliance must be sized correctly. If not, the appliance will not burn efficiently and could be starved for fuel.

gas riser diagram
This is a typical gas riser diagram that I draw for clients. I color-code the pipes so it’s easy to understand what size pipe extends to each appliance. CALL ME if you want me to draw your gas riser diagram: 603-470-0508

How is a Gas Riser Diagram Created?

The first step is to list all of the gas appliances and then find out the Btu input listed by the manufacturer. This information is needed to start to size the main trunk line that leaves the natural gas meter or the pressure regulator on a propane (LPG) system.

The next step is to draw the pipes on a plan as a plumber would install them on the job. You must do this so you know the exact length of the pipe from the meter to all the appliances.

Who Can Draw A Riser Diagram?

I draw gas diagrams each week. I love doing it. CALL ME if you want me to draw yours. 603-470-0508.

tim carter master plumber

If you already know you want me to draw yours, just place your order here.

What Does a Gas Riser Diagram Cost?

I only charge a fraction of what you’ll pay a mechanical engineer to draw one. As of 2023, my price is just several hundred dollars.

My guess is the base price an engineering firm would charge would be about $1,000.00 or $1,500.00.

I’ve been a master plumber since 1981 and draw them for much cheaper than a mechanical engineer.

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How Long Does it Take to Draw One?

It usually only takes four or five days to draw a drawing that will pass the smell test at the building department. If you try to do it yourself, there’s a very good chance you’ll get the calculations wrong and your plan might be rejected. If you do get the drawing wrong and the pipes are not sized correctly, your


Kitchen Sink Loop Vent

loop vent for island sink
This is a time-tested loop vent for my daughter’s kitchen sink. It’s in a huge island 10 feet long by 5 feet wide. A decorative panel was installed where you see the blue painter’s tape on the floor. This panel hides the loop vent and water supply pipes. CALL ME if you need me to draw your plumbing riser diagram: 603-470-0508 – I also provide affordable DIY phone coaching to help you install all your plumbing. I’ve been a master plumber since 1981.

Kitchen Sink Loop Vent – How One Works

A loop vent is a special pipe configuration that is used when a sink is not located against a wall. Sinks in islands need a loop vent or otherwise, the vent pipe would pierce the countertop and proceed to the ceiling much like a brass fireman’s pole. No one wants that look in a kitchen!

A typical vent pipe for a sink that’s on a wall is hidden inside the wall. The vent pipe travels up the wall and usually connects with other vent pipes. These pipes are collected into one and that pipe exits the roof.

Since most kitchen sinks are located centered on a window, this sink vent pipe can almost always be found in the wall cavity on either side of the window.

Why Does a Sink or Plumbing Fixture Need a Vent?

Vent pipes supply needed air into the plumbing system from the roof vent pipe. Each time water or solid waste enters a drain pipe, it pushes the air that was in the pipe moments before toward the sewer or septic tank.

This air must be replaced and it’s achieved by the vent pipe. You may think that vent pipes work like a smoke stack exhausting sewer gas. The opposite is true. Air travels down the pipes from the roof into the system.

What Size Pipes Are Needed for a Loop Vent?

You must use a minimum of 2-inch pipe for the actual drain stack and vent pipes. The branch arm pipe from the sanitary tee to the sink p-trap must NOT exceed 1 and 1/2 inches.

Where Does A Loop Vent Get Its Air?

The loop vent borrows air from the drain pipes in the plumbing system. When water starts to flow from the sink into the drain pipes, gravity pulls it to the bottom of the horizontal drain pipe. Air can flow back across the top of the flowing water to feed air back into the loop vent.

Since a 1 and 1/2-inch drain pipe was used for the sink, it’s impossible for that pipe to deliver enough water to fill a horizontal 2-inch drain pipe. This is why there’s always enough air in the system to satisfy the need.

Is a Pressure-Relief Vent Required?

To the best of my knowledge, only the city of New Orleans requires a pressure-relief vent. This dry vent is located just above the vent wye on the vent side of the loop vent. The pressure-relief vent then travels upwards until it exits the roof on its own or is connected to other dry vents within the system.

Where Can I Get More Help About Loop Vents?

I can help you. You can go here to arrange a 15-minute phone coaching call. I’ve been a master plumber since 1981 so I think I can answer all your questions.

tim carter master plumber seal


Draw Riser Diagram

Draw Riser Diagram

You may need a riser diagram to get a plumbing permit. They’re a very good idea because they prove to the plumbing department that you have a clear idea of the correct pipes to put in your home.

Who Draws Riser Diagrams?

I happen to draw them. I love doing it. I’ve been a master plumber since 1981 and to me drawing a riser diagram or plumbing isometric drawing is like solving a crossword puzzle. Call me now if you want me to draw your riser diagram in days: 603-470-0508

tim carter master plumber

What do Riser Diagrams Show?

A riser diagram for plumbing drain, waste, and vent (DWV) piping shows:

  • all drain pipes
  • all waste pipes
  • all fixture vent pipes
  • the building drain
  • general notes
  • pipe sizes
  • code-approved pipe connections

How Long Does it Take to Draw One?

I can draw a riser diagram in as little as 24 hours if you have an emergency. Otherwise it normally takes five business days. Other mechanical engineers might take weeks to produce this drawing.

Are Building Drain Layouts Important?

Yes, a building drain layout is very important. Non-plumbers almost always install the wrong fittings that cause serious clogs.

If you’re a DIY plumber, you should seriously consider asking me to draw your Building Drain Layout drawing.

Where Can I Get DIY Phone Coaching Help?

I offer DIY phone coaching. I’ve helped many homeowners over the phone install all the pipes in their homes. My favorite job was helping Zoe, a 28-year-old woman, in New Mexico with all the plumbing in her rural new home.

You can hire me for 15 minutes at a time and do either a voice or video call. Using video, I can see exactly what you’re up against to give you the best advice.

tim carter master plumber seal

Plumbing Isometric

What is a Plumbing Isometric Drawing?

A plumbing isometric drawing is a three-dimensional illustration that shows all the drain, waste, and vent plumbing lines that are in a building.

Why is a Plumbing Isometric Drawing Needed?

These drawings are required to get a plumbing permit in just about every city and town in the USA. The drawing indicates to the plumbing and building department that you understand the following:

  • the correct size of drain pipes for each fixture
  • the correct size of the vent pipe to each fixture
  • the correct size of the building drain
  • the correct orientation and connection of pipes within a fixture group

The inspector wants to make sure you know all of the above information so they don’t have to tell you to rip out all the pipes and start over when they show up for an inspection.

What Does a Plumbing Isometric Drawing Look Like?

Here’s a typical plumbing isometric drawing created by master plumber Tim Carter. Call him at 603-470-0508 if you want him to draw yours:


plumbing isometric drawing call 603-470-0508