Gas Project Approval Requirements: Sheets and Documents

Updated: 2026-10-27

Natural gas project approval means the distribution company reviews the drawings, calculations and attachments. A missing title block field or a wrongly written calculation line can send the project back.

This guide lists what should be in the approval file, as far as the sources say. The most detailed rules are in the Samgaz specification. Other Turkish gas distribution companies may differ.

First: find your company's rules

Calculation rules are largely shared between companies, but sheet and title block rules are not [1]:

Sheet size (A0–A4) is not stated in any source reviewed [1]. For İGDAŞ project approval, or any other company's, ask the distribution company directly for its current procedure.

Who prepares and submits the project?

• Project, construction and approval work is done by mechanical engineers at certified firms who hold the Natural Gas Internal Installation Engineer Competence Certificate under TS EN ISO 17024 [2].
• In Samgaz, only the firm's authorised engineer brings and follows up the project, and projects are drawn by computer [3].

1. Sheet content and order

In Samgaz, sheets are laid out left to right [4]:

1. Project cover
2. Site plan
3. Basement plan
4. Ground floor plan
5. Typical floor plans
6. Isometric diagram
7. Calculation tables
8. Details

Drawing points to watch [5]:

• Scale 1:50 or 1:100, as long as the drawing stays legible.
• Section numbers, diameters, lengths and flows on both the plan and the isometric.
• Appliance brands and capacities on the plan and the isometric.
• The service box outlet pressure and connection method written on the project.
• Floor and flat numbers, and room names as in the zoning plan.

Required details include wall penetrations, the meter connection, buried pipework, ventilation openings and the boiler flue [5].

For the drawing steps, see how to draw a natural gas installation project.

2. Title block (cover) fields

Fields legible on the Samgaz cover [6]:

• Designer's stamp and approval box, company approval box
• Building installation no, meter type and count, service box pressure, operating pressure
• List of flats (flat no / installation no)
• Building district, neighbourhood, street, parcel details, number of floors, flats/shops, total area, total capacity (m³/h)
• Designer's authorisation and chamber registration numbers
• Firm name, authorisation no, tax details, address, telephone
• Drawn-by and checked-by signatures, scale, revision number

Signatures and stamps are completed after the project has been copied [7].

3. Calculation sheet

The pipe sizing sheet has 12 columns [8]:

It comes with:

• A ζ form showing fitting counts for each section [9].
• Critical path lines. Samgaz sample: "Critical circuit 1: 1+2+3+4 = … ≤ 1 mbar (riser)" and "… ≤ 0.8 mbar (in-flat)" [10].
• At least three decimal places in calculations [10].
• Where needed, boiler flue, ventilation, 300–21 mbar pressure drop and dead volume calculations [10].

The method is explained in natural gas pipe sizing calculation.

4. Material list

The cost table in the MEB sample project has these columns: serial no, material description, quantity, unit and amount [11]. Rows run through appliances, flexible connectors, pipes by size (metres), ball valves, brackets, meter box, elbows and tees, earthing rod, sockets, reducers and labour [11].

5. Documents in the project file

In Samgaz, the project file contains [12]:

• A contract with the customer including at least a 2-year warranty
• A project application letter
• A project and appliance information form
• An installation insurance policy
• Flue undertakings and flue reports for flued appliances
• A domestic regulator catalogue marked to show it meets demand [13]
• For boiler projects, brochures for fittings, burner and boiler [5]

The document list may vary by company.

6. Submission, rejection and revision

• In Samgaz, the project is submitted in 3 copies; if approved, 2 are returned to the firm [12].
• The revision number is 00 at first submission and goes 01, 02, 03 on later ones [14].
• A rejected project is resubmitted in 3 copies including the rejected ones [12].
• Online approval is done with an e-signature through the subscriber management system [14].

Final check before submission

The MEB checklist: AKV, meter and pre-meter valve, appliances and flue connections, merged isometric, labels and cost table [15]. Add a complete title block and written critical path lines.

How to do it with GazPlan

The "Prepare for submission" button in GazPlan's Sheet tab produces a single ZIP: project file, printable sheet, calculation sheet, material list, check report and survey photos. For Samgaz, the title block fields on p. 226 are used; in other regions the title block is provisional and should be compared with the company's format. If a project is returned, the "Return note" tool marks the reasons and "New version" increments the revision while keeping earlier versions.

• Open the program
• Free calculators
• Distribution companies and approval 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, sections 2 and 5.
2. İGDAŞ Doğal Gaz İç Tesisat Teknik Esasları (Technical Principles) 2017, p. 60.
3. SAMGAZ İç Tesisat Şartnamesi (Internal Installation Specification), Rev. 2019.03, pp. 236–237.
4. Samgaz Rev. 2019.03, p. 225 (clause 29.1).
5. Samgaz Rev. 2019.03, pp. 224–225.
6. Samgaz Rev. 2019.03, p. 226.
7. Samgaz Rev. 2019.03, p. 223.
8. Samgaz Rev. 2019.03, p. 216 (Table 31); İGDAŞ 2017, p. 25 (Form 2).
9. Samgaz Rev. 2019.03, p. 215 (Table 30); İGDAŞ 2017, p. 24 (Form 1).
10. Samgaz Rev. 2019.03, p. 224.
11. MEB, Bilgisayarda Doğalgaz Tesisat Projesi (Computer-Aided Natural Gas Installation Project), 2015, pp. 28–29.
12. Samgaz Rev. 2019.03, pp. 237–238.
13. Samgaz Rev. 2019.03, p. 225.
14. Samgaz Rev. 2019.03, p. 238.
15. MEB 2015, p. 33.