Free Practice Questions for MMO MTDT Interior Gas Installation

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Sample MMO MTDT Interior Gas Installation Practice Questions

Try these sample questions to review concepts for the MMO MTDT Interior Gas Installation exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 20+ question experience with AI tutoring.

1An MTDT project shows a pipe as segment B-C in the calculation table. What makes its design traceable across the submission?

A.Using the same segment label, endpoints, length and diameter on the isometric drawing

B.Listing only the total apartment gas demand

C.Replacing segment labels with appliance brand names

D.Showing diameters only in the architectural title block

Explanation: A reviewer must connect each hydraulic result to a physical pipe segment. Consistent labels, dimensions and diameters make discrepancies between drawings and calculations visible.

2A gas route has horizontal runs of 6 m and 4 m joined by a 3 m vertical rise. What developed straight-pipe length belongs in its resistance table before fitting allowances?

A.10 m

B.13 m

C.7.8 m

D.16 m

Explanation: The gas follows all three pipe lengths, so the developed length is 6+4+3 = 13 m. A plan projection or diagonal distance does not represent the actual flow path.

3The architectural plan shows a branch feeding a kombi and an oven, but the isometric drawing shows only the kombi. The calculation excludes the oven. What should the designer do first?

A.Increase every diameter by one nominal size

B.Keep the calculation because the larger appliance is included

C.Reconcile the appliance schedule and both drawings, then recalculate affected segments

D.Apply a diversity factor to the omitted oven without updating drawings

Explanation: The load inventory and the physical network must agree before sizing is meaningful. Correcting the documentation identifies which common segments carry both appliance demands.

4A branch was relocated after project approval. Which record best supports a safe commissioning review?

A.The old approved drawing with an oral explanation

B.A revised route drawing and updated affected calculations submitted through the distributor's change procedure

C.A photograph of the meter alone

D.An unchanged resistance table with a new date

Explanation: A route change can alter length, fittings, clearances and pressure losses. Updated drawings and calculations allow the distributor's applicable approval and commissioning process to assess the actual installation.

5A common riser segment supplies four identical apartments at 3.0 m³/h each. For this exercise, the approved simultaneous-use factor is 0.75 for that group. What design flow passes through the common segment?

A.3.0 m³/h

B.12.0 m³/h

C.9.0 m³/h

D.16.0 m³/h

Explanation: The connected flow is 4 × 3.0 = 12.0 m³/h. Applying the stated group factor once gives 12.0 × 0.75 = 9.0 m³/h; the factor is an exercise input, not a universal distributor rule.

6For an upward gas riser, air density is 1.20 kg/m³ and gas density is 0.75 kg/m³. Ignoring friction, what change in gas pressure relative to local atmospheric pressure occurs over a 12 m rise? Use Δpgauge = (ρair-ρgas)gH and g = 9.81 m/s².

A.It decreases by 53 Pa

B.It increases by 53 Pa

C.It increases by 141 Pa

D.It decreases by 88 Pa

Explanation: Gauge pressure increases by (1.20-0.75) × 9.81 × 12 = 53.0 Pa. Both absolute pressures fall with height, but atmospheric pressure falls faster because air is denser.

7A riser has 21 mbar inlet gauge pressure. To one appliance, friction and local losses total 1.8 mbar, elevation adds 0.4 mbar, and a downstream component loses 0.7 mbar. The appliance needs at least 19.0 mbar. What is the result?

A.18.1 mbar; it fails

B.19.6 mbar; it passes

C.20.3 mbar; it passes

D.18.9 mbar; it fails

Explanation: Available pressure is 21-1.8+0.4-0.7 = 18.9 mbar. This is 0.1 mbar below the stated minimum, so the path needs redesign despite the beneficial elevation effect.

8Two branches leave a common riser junction. Their calculated downstream losses are 0.6 and 1.1 mbar. Which loss belongs in the pressure check for the second branch?

A.The common upstream loss plus 1.1 mbar

B.The common upstream loss plus 1.7 mbar

C.Only 1.1 mbar, because the junction resets pressure

D.The average of 0.6 and 1.1 mbar

Explanation: A path includes the common upstream pipe and the branch actually followed. Loss in a parallel branch is not added in series, although both branch flows contribute to the upstream segment demand.

9A kombi delivers 28 kW with efficiency 0.90 on a lower-heating-value basis. Gas lower heating value is 9.5 kWh/m³ at the specified reference conditions. What reference volumetric flow is needed?

A.2.65 m³/h

B.2.95 m³/h

C.3.27 m³/h

D.3.78 m³/h

Explanation: Fuel input is 28/0.90 = 31.11 kW. Dividing the unrounded input by 9.5 kWh/m³ gives 3.27485 m³/h, or 3.27 m³/h to two decimal places, at the heating value's reference conditions.

10A dwelling branch feeds a 3.2 m³/h kombi and a 0.9 m³/h oven. Assume both operate together and no diversity applies. What flow sizes the branch before their tee?

A.4.1 m³/h

B.3.2 m³/h

C.2.3 m³/h

D.0.9 m³/h

Explanation: The common branch carries both demands, so its design flow is 3.2+0.9 = 4.1 m³/h. After the tee, each branch carries only its own downstream appliance load.

About the MMO MTDT Interior Gas Installation Exam

Independent practice for MTDT interior natural-gas engineering. Work through drawing consistency, riser and dwelling demand, pipe resistance, pressure budgets and combustion-air judgment.

Exam sponsor: TMMOB Makina Mühendisleri Odası (MMO) / PBK. The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Assessment

The 150-minute project covers an apartment main riser and an interior kombi/oven installation, including architectural and isometric drawings, resistance tables and pipe sizing. Scored out of 100, with 70 required. The scheme does not identify a separate oral or hands-on assessment.

Time Limit

150 minutes

Passing Score

70/100

Exam / Certification Fees

Published PBK tariff checked 21 October 2026: certificate TRY 1,500 including VAT; no additional examination fee. Training separate; confirm current booking charges.

Exam sponsor website

Fees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.

Official sources

PBK MTDT qualification scheme · Source checked 2026-10-21Project scope, training prerequisites, 150 minutes and 70/100 threshold.
PBK current fee page · Source checked 2026-10-21Engineering certification tariff; training cost is separate.
MMO 2026 course catalogue · Source checked 2026-10-212026 MTDT offerings with separate examination information; chosen-sitting conditions require provider confirmation.

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

4 items (20%)

Project documentation

Architectural/isometric consistency and traceable calculation schedules.

4 items (20%)

Main-riser design

Demand, elevations and critical network paths.

4 items (20%)

Interior piping

Appliance input and dwelling branch sizing.

6 items (30%)

Hydraulic calculations

Velocity, Darcy/local losses and pressure budgets.

2 items (10%)

Ventilation and flues

Free-area calculations and combustion-air interactions.

Preparing for the MMO MTDT Interior Gas Installation Exam

What You Need to Know

Passing score: 70/100
Assessment: The 150-minute project covers an apartment main riser and an interior kombi/oven installation, including architectural and isometric drawings, resistance tables and pipe sizing. Scored out of 100, with 70 required. The scheme does not identify a separate oral or hands-on assessment.
Time limit: 150 minutes
Exam / certification fees: Published PBK tariff checked 21 October 2026: certificate TRY 1,500 including VAT; no additional examination fee. Training separate; confirm current booking charges. Official sources

Using Our Practice Resources

Work through all 20 available questions
Review every answer and explanation
Track weak areas and revisit them
Use our AI tutor for tough concepts

MMO MTDT Interior Gas Installation: Suggested Study Strategy

1Trace each resistance-table segment to the drawing.

2Keep reference and actual gas-volume bases explicit.

3Use current requirements of the relevant distributor; supplied exercise limits are not universal rules.

Frequently Asked Questions

Is this the official topic weighting?

The reviewed scheme defines the project scope but does not publish a percentage split among these study categories. These are editorial practice proportions, not official marks.

What are the eligibility and language requirements?

The scheme lists mechanical engineering and at least 12 hours each of basic and interior gas-installation training. Permitted response languages are not established by the reviewed sources; confirm current eligibility and language arrangements directly with MMO.

Do these MCQs replace drawing practice?

No. Complete full riser and dwelling projects with architectural and isometric drawings, segment tables and distributor-specific requirements alongside this English study resource.