Gas Pipe Size Calculator

Here's a table with estimations for gas pipe sizes based on typical gas demand and pipe lengths:

Gas Demand (BTU/hr)	Pipe Length (feet)	Estimated Pipe Size (inch)
Up to 50,000	Up to 50	1/2
Up to 100,000	Up to 100	3/4
Up to 200,000	Up to 150	1
Up to 400,000	Up to 250	1 1/4
Up to 800,000	Up to 500	1 1/2
Up to 1,600,000	Up to 1000	2

Please note that these estimations are for illustrative purposes and may vary depending on specific requirements, local regulations, and professional recommendations. It's important to consult with a qualified gas engineer or plumber for accurate sizing and installation of gas pipes.

FAQs

How do I calculate gas pipe size?

• Gas pipe size is typically calculated based on factors such as gas demand (BTU/hr), pipe length, pressure drop, and allowable velocity. Several methods and formulas are used for sizing gas pipes, including the International Fuel Gas Code (IFGC) sizing tables or software programs specifically designed for gas pipe sizing.

What diameter gas pipe do I need?

• The diameter of the gas pipe needed depends on factors such as gas demand, pipe length, pressure drop, and allowable velocity. Standard gas pipe diameters in residential applications typically range from 15mm (1/2 inch) to 32mm (1 1/4 inch) in the UK.

How much gas can 22mm pipe carry?

• A 22mm gas pipe can typically carry gas flow rates up to approximately 35 cubic meters per hour (m³/h) or 1235 cubic feet per hour (cfh) under standard operating conditions.

How do I calculate what size pipe I need?

• To calculate the size of the pipe needed, you would typically consider factors such as gas demand (BTU/hr), pipe length, pressure drop, and allowable velocity. This information is then used to select the appropriate pipe diameter based on gas pipe sizing tables, formulas, or software tools.

What size gas pipe do I need for a combi boiler?

• The size of the gas pipe needed for a combi boiler depends on factors such as the gas demand of the boiler, pipe length, pressure drop, and allowable velocity. Typically, a 22mm (3/4 inch) gas pipe is recommended for most residential combi boilers in the UK.

Is gas pipe measured inside or outside diameter?

• Gas pipe sizes are typically measured by their outside diameter (OD) in the UK. For example, a 22mm gas pipe refers to a pipe with a 22mm outside diameter.

Can a gas pipe be too big?

• Yes, a gas pipe can be too big for a given application. Oversized gas pipes may result in reduced gas velocity, inefficient gas flow, increased installation costs, and potential safety hazards such as gas stagnation and condensation buildup.

What is the British standard for gas pipe sizing?

• Gas pipe sizing in the UK is governed by standards such as BS 6891 "Specification for the installation and maintenance of low-pressure gas installation pipework of up to 35 mm (R1 1/4)" and IGEM/UP/2 Edition 2 "Gas installations for educational establishments."

Do you need 22mm gas pipes?

• Whether 22mm gas pipes are needed depends on factors such as gas demand, pipe length, pressure drop, and allowable velocity. In many residential applications, 22mm gas pipes are commonly used for combi boilers and other gas appliances.

Can you go from 15mm to 22mm gas pipe?

• Yes, it is possible to transition from a 15mm gas pipe to a 22mm gas pipe using appropriate fittings such as reducers or couplings. This may be necessary to accommodate higher gas demand or longer pipe runs.

Do a combi boilers need 22mm gas pipes?

• Combi boilers typically require 22mm gas pipes to ensure an adequate gas supply and proper operation. However, the specific gas pipe size needed may vary depending on factors such as boiler capacity, gas demand, and installation requirements.

What is the British standard for domestic gas pipework?

• The British standard for domestic gas pipework is BS 6891 "Specification for the installation and maintenance of low-pressure gas installation pipework of up to 35 mm (R1 1/4)."

What is the rule of thumb for pipe sizes?

• A common rule of thumb for pipe sizes is to select a diameter that allows for adequate gas flow while minimizing pressure drop and velocity. This typically involves balancing factors such as gas demand, pipe length, and allowable pressure loss.

How do you measure pipe size UK?

• In the UK, pipe sizes are typically measured by their outside diameter (OD) in millimeters (mm) or inches (in). For example, a 22mm pipe has an outside diameter of 22mm.

What size pipe do plumbers use?

• Plumbers use various pipe sizes depending on the specific application and requirements. Common pipe sizes used in plumbing applications include 15mm (1/2 inch), 22mm (3/4 inch), and 28mm (1 inch) pipes.

Is a boiler gas supply 15mm or 22mm?

• The gas supply pipe for a boiler may be either 15mm or 22mm, depending on factors such as the gas demand of the boiler, pipe length, and installation requirements. In many cases, 22mm gas pipes are recommended for boilers to ensure an adequate gas supply.

What size gas pipe is too small for a boiler?

• A gas pipe that is too small for a boiler may result in inadequate gas flow, reduced boiler performance, and potential safety hazards. The specific minimum size of the gas pipe required for a boiler depends on factors such as the boiler's gas demand, pipe length, and pressure drop.

Should I use 22mm or 15mm for central heating?

• The decision to use 22mm or 15mm pipes for central heating depends on factors such as the heating system's design, boiler capacity, pipe length, and pressure drop. In many cases, 22mm pipes are used for larger central heating systems or higher flow rates.

What size gas pipe do you need for a gas fire?

• The size of the gas pipe needed for a gas fire depends on factors such as the gas demand of the fire, pipe length, pressure drop, and allowable velocity. Typically, a 15mm (1/2 inch) gas pipe is suitable for most residential gas fire installations.

What does the proper size diameter of a gas supply pipe depend on?

• The proper size diameter of a gas supply pipe depends on factors such as gas demand (BTU/hr), pipe length, pressure drop, allowable velocity, and installation requirements. It's important to size the pipe appropriately to ensure safe and efficient gas flow.

What is the outside diameter of 2 inch gas pipe?

• The outside diameter of a 2-inch gas pipe is approximately 60.3 millimeters (mm) or 2.375 inches.

What is the most common gas line size?

• The most common gas line size in residential applications is 22mm (3/4 inch) in the UK. However, smaller sizes such as 15mm (1/2 inch) are also common for low-demand appliances.

Does reducing pipe size increase gas pressure?

• No, reducing pipe size does not increase gas pressure. In fact, reducing pipe size may result in increased pressure drop due to higher fluid velocity, which can lead to decreased gas pressure downstream.

Should gas pipe be sleeved?

• Gas pipes may be sleeved (encased in a protective sleeve) in certain situations to provide additional protection against corrosion, mechanical damage, or environmental factors. Sleeve materials may include PVC, steel, or other suitable materials.

What size pipe can a domestic gas engineer work on?

• A domestic gas engineer typically works on gas pipes with sizes ranging from 15mm (1/2 inch) to 32mm (1 1/4 inch) in residential applications. These sizes are commonly used for gas appliances, boilers, heaters, and other gas systems.

What are the primary gas pipe sizing method commonly used?

• The primary gas pipe sizing methods commonly used include calculation based on gas demand (BTU/hr), pipe length, pressure drop, and allowable velocity. These methods may involve referencing gas pipe sizing tables, formulas, or software tools.

Why is gas pipe sizing important?

• Gas pipe sizing is important to ensure the safe and efficient delivery of gas to appliances while maintaining proper pressure and flow rates. Properly sized gas pipes help prevent issues such as gas leaks, pressure drop, inefficient operation, and safety hazards.

Can you run 2 boilers off one gas meter?

• Yes, it is possible to run two boilers off one gas meter, provided that the gas meter and piping system are sized appropriately to accommodate the combined gas demand of both boilers.

Can you run a combi boiler on 15mm pipe?

• Yes, a combi boiler can be run on 15mm (1/2 inch) gas pipe, depending on factors such as the boiler's gas demand, pipe length, pressure drop, and installation requirements. However, larger pipe sizes such as 22mm (3/4 inch) may be recommended for higher-demand boilers.

Which pipe is best for gas fitting?

• The best pipe for gas fitting depends on factors such as the type of gas, application, installation requirements, and local building codes. Common materials used for gas pipes include copper, steel, and cross-linked polyethylene (PEX).

Do I need to upgrade gas pipe for new boiler?

• Whether you need to upgrade the gas pipe for a new boiler depends on factors such as the boiler's gas demand, existing pipe size, length, pressure drop, and installation requirements. Upgrading the gas pipe may be necessary to ensure proper gas flow and operation.

When should I reduce my gas pipe size?

• Reducing gas pipe size may be necessary in certain situations to match the gas demand of appliances, accommodate changes in pipe length, reduce pressure drop, or optimize system performance. Proper sizing and installation are essential to ensure safe and efficient gas flow.

Do you need new pipework for a combi boiler?

• Whether you need new pipework for a combi boiler depends on factors such as the existing piping system, condition, size, and compatibility with the new boiler. In many cases, existing pipework can be used or modified to accommodate the new boiler.

What size gas pipe for a combi boiler?

• The size of the gas pipe needed for a combi boiler depends on factors such as the boiler's gas demand, pipe length, pressure drop, and installation requirements. Typically, a 22mm (3/4 inch) gas pipe is recommended for most residential combi boilers in the UK.

Can I fit my own gas combi boiler?

• Gas boiler installations must be carried out by Gas Safe registered engineers in the UK. DIY installation of gas boilers is not recommended due to safety concerns, legal requirements, and the need for professional expertise.

What are the rules for gas pipes in the UK?

• Gas pipe installations in the UK must comply with regulations such as the Gas Safety (Installation and Use) Regulations 1998 and standards such as BS 6891. These regulations cover aspects such as pipe sizing, materials, installation, ventilation, and safety precautions.

How far can you run 15mm gas pipe?

• The maximum allowable distance for running 15mm (1/2 inch) gas pipe depends on factors such as the gas demand, pressure drop, and installation requirements. It's advisable to consult with a qualified gas engineer to determine the appropriate pipe length for your specific application.

How do I know what size pipe fitting I need?

• To determine the size of pipe fitting needed, you should consider factors such as pipe diameter, thread size, material, and compatibility with other components. Pipe fittings are typically selected based on the size and type of the pipe being used.