Dome nut | hexagon | A4 | WS 9626
Stainless steel threaded cap A4 AISI 316 BSPT is designed for sealing and protecting pipe ends with tapered pipe threads. The product complies with ISO 7-1 and is used where secure sealing and high corrosion resistance are required. The hexagonal design enables assembly and disassembly using standard tools. The AISI 316 design provides excellent resistance to saltwater, chemicals, and aggressive media, ensuring a long service life in demanding environments.
AREA OF APPLICATION
The product is used in HVAC installations, marine environments, the process industry, water treatment, and food production. It is intended for applications where pipelines need to be closed temporarily or permanently to prevent leakage, and where the choice of material must withstand corrosion and chemical impact.
TECHNICAL SPECIFICATIONS
Product type: Pipe fitting
Product family: Hexagonal threaded cap
Material class: A4
Strength class: Not specified
Standard: ISO 7-1
Thread dimension: BSPT / Rc-thread (internal)
Design: Hexagonal cap with internal tapered thread
Surface finish: Untreated
Environment: Marine
Delivery unit: Piece
FREQUENTLY ASKED QUESTIONS (FAQ)
How does the seal work on a threaded cap with a tapered BSPT thread (ISO 7-1)?
BSPT (British Standard Pipe Tapered) has a tapered external/internal thread profile according to ISO 7-1. When the threaded cap is tightened, the threads are mechanically wedged together along the taper, which creates a very tight seal. To ensure 100% leak-proof performance for high-pressure or gas/liquid applications, the assembly should be supplemented with thread tape (PTFE) or hemp and pipe dope.
What is the advantage of a hexagonal grip when installing threaded caps?
The hexagonal design makes it easy to apply the correct torque during both assembly and future service/disassembly. You do not need pipe wrenches that risk damaging or scratching the material; instead, you can use standard open-ended or socket wrenches.
Why is acid-proof A4 / AISI 316 necessary for pipelines and plugs/caps?
Acid-proof A4 steel (AISI 316 / 1.4401) is alloyed with molybdenum, providing complete protection against crevice and pitting corrosion in demanding environments. This makes the threaded cap ideal for installations in the chemical industry, marine piping systems, food production, and outdoor facilities where the component is exposed to saltwater, corrosive liquids, or high temperatures.