Straight male stud couplings, NPT thread
Threaded fittings
Straight male stud couplings with an NPT thread bring a precision steel tube to a port machined to the American pipe thread system, using a cutting ring plus a union nut. The tapered NPT male thread seals on the thread flanks themselves, so no separate sealing face is needed. This category lists 92 versions, covering stud threads from NPT 1/8" to NPT 1-1/2" plus tube outside diameters from 4 LL up to 42 L.
Two sizes have to be fixed: the NPT thread of the tapped port, plus the tube series of the line. Besides series L as well as S, the range includes the extra light series LL, namely 4 LL (M8x1), 6 LL (M10x1) plus 8 LL (M12x1), typical of thin gauge lines. Materials on offer are zinc plated steel as well as stainless steel 1.4571, each also available without nut plus cutting ring.
An NPT thread looks close to a tapered metric thread, yet pitch as well as flank angle differ, so the two systems must never be paired. Thread size follows the tapped port on the equipment, tube series follows the installed line, the two values being independent: NPT 1" is offered on tube 25 S as well as on tube 28 L (M36x2). For repairs that keep the existing tube, bodies come without nut plus cutting ring, for example NPT 3/4" on tube 20 S.
Hydraulic power packs, pumps plus valve blocks of American design, along with machinery built to be exported into NPT territory. Equally used in plant as well as vessel construction whenever fittings tapped to NPT have to meet rigid steel tube. The fine sizes 4 LL plus 6 LL serve gauge, lubrication as well as pilot lines on test benches, while versions in 1.4571 run in chemical plants as well as wet areas.
