How to Draw a Natural Gas Installation Project

Updated: 2026-10-27

A natural gas installation project is the set of drawings and calculations showing the gas route from the service box to each appliance, the pipe sizes and appliance locations. This guide explains the drawing order and what Turkish gas distribution company specifications ask for at each step.

Numbers in brackets point to the sources at the end. Values differ slightly between companies, so check your region's current specification.

Before you start: which specification applies?

The calculation core is largely the same across Turkish gas distribution companies. Drawing rules are not [1]:

• Title block fields, scale and the 45° isometric rule are spelled out only in the Samgaz and Selçukgaz documents.
• The İGDAŞ 2017 technical principles contain no sheet, scale or title block rules; these should be in a separate approval procedure.
• The Kırgaz specification only states the 1:50–1:100 scale.

So the steps below are a general workflow. Always confirm the title block and sheet format with your distribution company.

Drawing order, step by step

The workflow in the MEB (Ministry of National Education) textbook on computer-aided gas projects is a practical starting point [2]:

1. Import the architectural plan at 1:50.
2. Place the gas appliances.
3. Draw the flue connections.
4. Locate the gas meter.
5. Design the building gas entry.
6. Place the main shut-off valve (AKV).
7. Draw the line from the AKV to each flat's meter.
8. Draw the lines from the meter to the appliances.
9. Draw the in-flat isometrics and merge them with the riser isometric.
10. Prepare the material (cost) list.

1. Site plan and floor plans

The site plan has two parts: a bird's-eye sketch showing at least two street names, the service box location and the building entrance, and a side elevation showing levels [3].

Floor plans are drawn for every floor the gas passes through. Doors, windows, flues, vents and room names are written, with the floor name and scale at the bottom right [3]. Samgaz allows 1:50 or 1:100 as long as the drawing remains legible [4].

2. Service box and building entry

The service box label shows its type, outlet pressure (21 or 300 mbar) and outlet direction. At the building entry, the insulating joint, earthing and, where needed, a magnesium anode are shown [5]. Samgaz asks for the service box outlet pressure and connection method to be written on the project [4].

3. Main shut-off valve and riser

• In İGDAŞ, the AKV is at most 2.10 m above floor level [6].
• Samgaz gives a range of 1.90–2.10 m [7]; the MEB sample says 1.8–2 m [5].
• If the distance between the AKV and the building entrance exceeds 15 m, a safety valve is added at the entrance [6].

Gas pipes must not pass through lift shafts, light wells, roof voids, chimneys or shelters [6]. Keep at least 15 cm from electrical and telephone lines and at least 30 cm from three-phase lines [6].

4. Meter location

Each flat's meter is placed at or as close as possible to its own entrance [8]. Locations above a chimney, above a lift door, on a balcony or above the flat's front door are not allowed [8]. The meter is at least 2 cm from the wall [8], and there is always a shut-off valve before it [5].

5. Appliance placement

Write the appliance type, brand and capacity (kcal/h) next to each appliance symbol [3]. Check these rules while placing them:

• A type (flueless) appliances cannot go in a space under 12 m³; B type (flued) appliances cannot go in a room with a net volume under 8 m³ [9].
• The room needs at least 1 m³ for every kW of appliance input [9].
• Bedrooms, bathrooms and toilets are not allowed for A and B type appliances [9].
• Every appliance inlet has a shut-off valve. Flexible hoses are at most 150 cm for kitchen appliances and 60 cm for boilers and water heaters [10].

See the flue and ventilation rules guide for details.

6. Drawing and numbering the pipe sections

Numbering starts at the gas delivery point. A stretch with the same flow, pressure and diameter gets one number; when any of these changes, a new number starts [11]. Samgaz requires section numbers, diameters, lengths and flows on both the plan and the isometric [4].

The symbols to use (valve, meter, regulator, boiler, cooker, flue, rising and falling line) are given in İGDAŞ Figure 2 [12].

7. Isometric

Each pipe section is labelled with "section no, flow (m³/h), length (m), DN", and labels must not overlap [14]. The riser isometric starts at the service box and is finally merged with the in-flat isometrics [14].

8. Title block and sheet layout

In Samgaz, sheets are arranged left to right: cover, site plan, basement, ground and typical floor plans, isometric, calculation tables and details [15]. The title block holds the building address, parcel details, number of flats, total capacity, designer and firm details, scale and revision number [15].

For the calculation sheet and attachments, see gas project approval requirements.

9. Pre-submission check

The MEB checklist asks [16]:

• Is there an AKV?
• Is there a meter, with a valve before it?
• Are the appliances and flue connections drawn?
• Are the in-flat and riser isometrics merged?
• Are all labels (flow, length, diameter) written?
• Is there a cost table?

Run the pressure drop and velocity checks at this stage too; the method is in natural gas pipe sizing calculation.

How to do it with GazPlan

GazPlan is a browser-based natural gas project drawing program. Its project wizard asks for the building type, floors and flats, appliances and distribution company, then opens a calculated draft. In the Drawing tab you place the service box, meter, valves, elbows, tees and appliance symbols and switch between floor plan and isometric. PNG, JPG, DXF or PDF files can be loaded as an architectural underlay.

The "Check" button lists missing service boxes and valves, pressure drop, velocity, appliance-room rules and missing title block fields. The Sheet tab exports the isometric, title block and calculation page as an A3 PDF. The isometric angle comes from the selected region's profile.

• Open the program
• Free calculators
• Distribution companies and specification differences

This guide is for information only; projects are prepared by a certified engineer and the distribution company's current specification prevails.

Sources

1. GazPlan specification comparison (13 Turkish gas distribution company specifications), 2026, section 4 item 10.
2. MEB, Bilgisayarda Doğalgaz Tesisat Projesi (Computer-Aided Natural Gas Installation Project), 2015, pp. 24, 30.
3. MEB 2015, pp. 6–12.
4. SAMGAZ İç Tesisat Şartnamesi (Internal Installation Specification), Rev. 2019.03, p. 224.
5. MEB 2015, pp. 13–20.
6. İGDAŞ Doğal Gaz İç Tesisat Teknik Esasları (Technical Principles) 2017, pp. 27–30.
7. Samgaz Rev. 2019.03, p. 102.
8. İGDAŞ 2017, pp. 32–33.
9. İGDAŞ 2017, pp. 36–37.
10. İGDAŞ 2017, p. 35.
11. İGDAŞ 2017, p. 18.
12. İGDAŞ 2017, p. 23 (Figure 2).
13. Samgaz Rev. 2019.03, p. 229; Selçukgaz İç Tesisat Şartnamesi 2019.01, p. 215.
14. MEB 2015, pp. 25–28, 30.
15. Samgaz Rev. 2019.03, pp. 225–226.
16. MEB 2015, p. 33.