07/10/2026
Why We Don't Weld Pipes Meant for Drinking Water
If a pipe is going to carry water people actually drink, or gas running through a building 24/7, the joint matters more than most of us think.
Here's the thing about welding: you're putting heat into stainless steel that was chosen for its corrosion resistance in the first place. Heat changes that surface. You also get scale and oxidation on the inside of the tube — and in a drinking water line, that's material sitting in the water. On gas lines it's a different worry: an open flame working right next to the thing you're trying to keep sealed.
That's where GB Double-press Fittings (model: GB Series press Fittings) come in. No torch. The pipe goes into the socket, you mark the insertion depth, the pressing tool crimps the joint, done. The seal comes from a compressed ring — food-grade silicone (FDA certified) or EPDM, and EPDM is the one usually specified for potable water and gas supply systems because it stands up to temperature and oil exposure.
The body of the fitting is 304 or 316L stainless steel, so corrosion resistance is in the material itself, not applied afterward. Sizes run DN15 (φ16) up to DN100 (φ108), which covers most residential and public-building risers. Pressure ratings sit at 1.6 MPa for cold water and 1.0 MPa for hot water up to 95°C. Standard working range is -20°C to 95°C; if a project needs -40°C to 120°C, there's a high-temperature version, but that means changing the sealing ring.
For anyone planning ahead, the practical part is this: these joints are built to match the service life of the building, maintenance-free. No re-torquing years later. No weld scars behind a finished wall that nobody wants to open up again.
WENZHOU ZHENGXIN PIPE FITTINGS CO., LTD has been producing this range since 2013 — press-fit elbows, couplings and tees, compliant with EN 10312 and CE certified, with exports making up around 70% of sales and Europe as the main market. Elbows, couplings, tees, unions, caps: the full set from one supply chain.
So, a question for the contractors and facility people here — when you spec a potable water riser, do you think about what's sitting inside the pipe after the joint is made, or does the pressure rating make the call for you?
