Threaded fittings
Pneumatics
Threaded fittings join pipes, hoses and equipment through a standardised pipe thread. The range holds 5608 items, 4127 of them placed directly in this category, spread over 15 groups that reach from male stud couplings through double nipples and reducing nipples to sealing washers. Common sizes run from G 1/8" through Rp 1/4" and NPT 1/4" up to Rp 2".
Two points govern the choice: thread form and sealing principle. Parallel threads G and Rp seal on a gasket or a sealing edge, tapered threads R and NPT seal in the thread flanks themselves. Pressure ratings reach 25 bar, 40 bar or PN 16 bar, depending on the design. Available materials cover brass, stainless steel 1.4571 as well as 1.4408, plus PVC-U and polypropylene; gaskets are made of FKM.
Threaded fittings - product types
Start from the thread form of the mating part: tapered R as well as NPT threads seal in the flanks and call for a thread sealant, parallel G plus Rp threads need a gasket or a sealing edge on the shoulder. Then fix the nominal size, for example G 1/8" on control lines up to Rp 2" on main lines. Where thread size steps, reducing nipples bridge the gap, such as G 3/4" down to G 1/4". Tighten on the intended hexagon, spanner size 17 to 32 mm, never on the body.
Compressed air distribution as well as hydraulic circuits in machine building, where valves, cylinders plus air service units connect through G and R threads. In pipework and vessel construction, sockets, tees and 90° elbows in brass or stainless 1.4571 form the branches, while PVC-U solvent sockets plus polypropylene parts carry the process lines. Gaskets to DIN 11851 belong to threaded pipe unions in food and beverage plants. NPT versions serve equipment built to American standards.
