A gas line is judged on the joints, not the pipe. TUPY Brazil threaded fittings in blackheart malleable cast iron are approved by DVGW — the German association whose approval is the reference for gas and water fittings in Europe — and are supplied for fuel gas distribution across the Gulf, Iraq and the wider Middle East from stock in Dubai.
Malleable cast iron is used on gas because of what it does when something goes wrong. Grey cast iron fails without warning: the graphite flakes in it behave like ready-made cracks. Blackheart malleable iron is heat-treated until that graphite is compacted into nodules, and the result stretches about 10 per cent before it breaks rather than shattering. On a buried or boxed-in gas line, a fitting that deforms under ground movement instead of splitting is the difference between a callout and an incident.
The grade is JMB 350-10 to ISO 5922, with a minimum tensile strength of 350 MPa and minimum elongation of 10 per cent.
TUPY does not approve welding of its fittings. Welding a malleable iron fitting puts martensite and cementite into the heat-affected zone and leaves gas porosity behind; the joint looks finished and is structurally weakened. On a line carrying fuel gas this is the single most common avoidable failure, and it is why the threaded joint is made up rather than welded.
TUPY BSP fittings seal on the thread itself, to ISO 7-1: an internal parallel thread Rp against an external taper thread R. There is no separate gasket to age, and no weld to inspect.
Threaded BSP fittings are rated at 25 bar from -20 to +120 °C. Between 120 and 300 °C the permitted pressure is interpolated, and above 300 °C it is 20 bar. Gas distribution sits far below these figures, which is the point — system design should allow a safety factor of at least four times the maximum working pressure.
Where the TUPYPRES press system is used instead of threads, the rating for gas is 10 bar at up to 70 °C on steel pipe, 7 bar on PE100 and 4 bar at up to 40 °C on PEX.
DVGW approval covers gas and water products to European standards and is the one most often asked for on gas work. The fittings also carry FM Approval and UL Listing, ABNT and INMETRO certification, and are made under ISO 9001 and ISO 14001 systems. TUPY threaded fittings are the only ones in the Middle East supplied with a 10-year warranty.
| Material | Blackheart malleable cast iron JMB 350-10 (ISO 5922, EN 1562, ABNT NBR 6590) |
|---|---|
| Standards | EN 10242, ISO 49, ABNT NBR 6943 |
| Sizes | 1/4 inch to 6 inch |
| Maximum working pressure | 25 bar from -20 to +120 °C |
| Hydrostatic test pressure | 100 bar (1/8 to 4 in), 64 bar (5 to 6 in) |
| Threads | Internal parallel Rp, external taper R, to ISO 7-1 |
| Finish | Hot-dip galvanised to ISO 1461 and ABNT NBR 6323, or black (oiled) |
Yes. TUPY Brazil BSP threaded fittings are manufactured for the conveyance of liquid and gaseous fuels among other fluids, and carry DVGW approval for gas and water products to European standards.
Both are supplied. Hot-dip galvanised to ISO 1461 is the normal choice where the line is buried, outdoors or in humid coastal air, which covers most of the Gulf. Black (oiled) fittings are used on dry indoor runs.
No. TUPY does not recommend or approve welding of its fittings. The practice is common but it embrittles the heat-affected zone and causes leaks.
1/4 inch to 6 inch, in both BSP and NPT thread forms.
Stocked in Dubai and shipped across the Gulf, Iraq, Turkey, the Caucasus and South Asia.
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