FAQ
TL;DR: Apartment gas lines run at approx. 40 mbar; welding “is not rocket science” when a qualified installer tests and documents it. Electrode welding or threaded fittings can be appropriate. [Elektroda, Anonymous, post #17160978]
Why it matters: For apartment owners and installers moving or modifying gas lines, this explains safe joining choices and leak‑testing so work stays tight and compliant.
Quick Facts
- Low‑pressure apartment gas installations operate at approx. 40 mbar; joints should carry only thermal‑expansion and self‑weight stresses. [Elektroda, Anonymous, post #17160978]
- Allowed methods: braze copper or weld seamless steel; use threaded connections only where welding isn’t possible (e.g., at a gas meter). [Elektroda, MARCIN.SLASK, post #17161276]
- Every welded section should be tightness‑tested, and the installer should document it with a stamp/record. [Elektroda, SKM 1964, #17161275]
- Electrode (electric) welding was used successfully in this case, with leak‑tight results confirmed after testing. [Elektroda, marqqv, post #17164541]
- Avoid cutting holes into existing lines to branch; use fittings and a specialist for safer results. [Elektroda, jalop, post #17164235]
Can I weld apartment gas pipes with an electrode and still keep it gas‑tight?
Yes—if a qualified welder performs the work and the joint passes a leak test. Domestic apartment lines run around 40 mbar, so achieving tightness is manageable with proper prep. Avoid adding mechanical stresses to the joint beyond thermal expansion and its own weight. If you are not a welder, hire a professional service. Always verify tightness after the modification. [Elektroda, Anonymous, post #17160978]
Is brazing the same as welding for gas installations?
No. Brazing (hard soldering) and welding are different joining processes. As one forum expert put it, “hard soldering is not welding.” Your installer will choose the correct method for the pipe material and location. Keep method selection tied to material and approved practice. [Elektroda, Doominus, post #17160975]
What joining methods are typically allowed inside apartments?
Use brazing for copper and welding for seamless steel. Threaded connections are permitted only where welding cannot be done, such as near a gas meter. This approach aligns with common residential practice noted by experienced installers. Confirm the chosen method with your certified installer before work begins. [Elektroda, MARCIN.SLASK, post #17161276]
Who can perform and sign off a gas pipe modification?
A specialist installer with a valid exam should perform the job and then sign the work. That signature ties responsibility to the person who completed the modification. Ask to see current credentials before work starts. Request documentation at handover. [Elektroda, MARCIN.SLASK, post #17161276]
How do I verify tightness after gas pipe welding?
Follow a simple check with your installer:
- Ask the installer to perform a tightness test on the modified section.
- Observe the approved test method used and its result.
- Request written confirmation; “He should stamp what he did.”
This gives traceable proof of leak‑tightness. [Elektroda, SKM 1964, #17161275]
Is it okay to cut into an existing pipe to add a branch?
Avoid cutting or drilling holes to branch lines. A seasoned pro called that approach unwise for your case. Instead, have a specialist use the right fittings (e.g., tees) and proper techniques. This reduces risk and simplifies testing and documentation. [Elektroda, jalop, post #17164235]
When should I choose threaded fittings instead of welding?
Choose threading where welding isn’t possible or advisable, such as in meter areas or tight spaces. Threaded connections allow safe assembly where open flames or welding clearance are restricted. Confirm thread quality and always perform a leak test after assembly. [Elektroda, MARCIN.SLASK, post #17161276]
Can I weld near the gas meter, or must I thread there?
Use threaded connections near the gas meter. That area is cited as an example where welding is not performed. Plan for accessible threading and assembly space, and complete a documented leak test afterward. [Elektroda, MARCIN.SLASK, post #17161276]
What pressure do household gas installations work at?
Typical apartment gas installations operate at approximately 40 mbar. Work methods and leak tests should suit low‑pressure service. Keep joints free of extra mechanical loads to maintain tightness at this pressure. [Elektroda, Anonymous, post #17160978]
What can cause a welded joint to leak later?
Introducing loads beyond thermal expansion and the pipe’s own weight can compromise a joint. Poor alignment or supports can add stress and create leaks over time. Always test after work and ensure proper supports to avoid unintended loading. [Elektroda, Anonymous, post #17160978]
I’m moving a stove about 3 meters—what’s the recommended approach?
Engage a specialist and extend the line using proper fittings and approved methods. Avoid ad‑hoc hole cutting into existing piping. Plan the route, use tees and elbows as needed, and complete a documented tightness test when done. [Elektroda, jalop, post #17164235]
Is electric (SMAW/electrode) welding acceptable versus gas welding here?
Yes. The guidance referenced does not mandate gas versus electric; it requires welding for steel where applicable. A qualified installer selects the process and proves tightness afterward. Request documentation of the completed test and their credentials. [Elektroda, MARCIN.SLASK, post #17161276]
Do I need a full company, or is a single certified pro enough?
A competent professional completed this type of work and confirmed tightness without involving a large company. The key is proven competence and a verified leak test at the end. Ask for test results and keep the documentation. [Elektroda, marqqv, post #17164541]
What space or access should I allow for welding?
Provide sufficient space for safe welding and inspection. If access is too tight, use threaded fittings instead of forcing a weld. Plan clearances in advance to speed work and help the tester reach every joint. [Elektroda, SKM 1964, #17163192]
