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SS 316 High performance fittings > Pipe fittings > Overview > Tapered

  Pipe fittings
Overview - Tapered
The male and female threads have a tapered flank and controlled truncation at the crest and root to assure metal to metal crest-root contact just as the male-female thread flanks make contact. Upon further tightening, the thread crests flatten out and allow the flanks to make full contact. This full thread profile contact give the tapered threads self-sealing ability. However, recommends use of preapplied thread sealants because of variations in condition of mating threads, fitting and port materials or assembly procedures.
Suggested Applications
The standard bearer in industry over the years, Tapered Pipe Fittings are still widely used in static pressure, process piping &
instrumentation systems. Tapered Pipe Fittings are cost-effective and widely available. Tapered Pipe Fittings are preferred in high temperature systems or when exposed to highly caustic media where a metal-only seal is required. In most other applications, however, Tapered Pipe Fittings must be carefully considered given its inherent torque sensitivity. Overtightening
can distort the threads too much and create a leakage path. Repeated assembly and disassembly should be minimized.
Tapered Pipe Fittings are not to be used for mechanically joining components in a system where load would be placed
perpendicular to the plumbing line. This weight will further weaken the sealing joint.
Feature Threaded-tapered
Pressures Very high to 7200 psi (static systems only)
Temperature Stainless: -425° to 1200°F Brass:-40° to 400°F; Monel:-65° to 800°F
Vibration Resistance Poor
Materials Available SS 316/SS 316L stainless steel; M405 Monel; CA377/CA360/CA345 Brass
Size Available (nominal) 1/8” – 2”
Seal Reliability Good in static systems Poor in dynamic systems
Medium tolerance to minor thread
imperfections Medium tolerance to assembly variation
Thread & Port Preparation Anaerobic sealant or thread tape
Ease of Assembly Medium L1 thread gauge & basic ass’y practices must be followed
Ease of Maintenance Limited breaks and remakes due to metal
deformation of threads
Specification Conformance J514, MIL-F-18866; ANSI B1.20.1,
(design & thread) JIS B0203; BS 21, ISO 7/1