TRANSITION FITTINGS OVERVIEW
Spears® Transition fittings are designed primarily for adapting plastic-to-metal systems. These fittings, especially the Special Reinforced (SR) Female Plastic Thread style, can also be used for superior strength in make-up of plastic threaded joints. Spears® offers a variety of transition adapter fittings specified below. All have standard ASTM socket sizes for IPS pipe and NPT threads, except for the Gasket Sealed style that uses a straight thread with elastomer seal. All other threads should be assembled with a quality grade thread sealant that is compatible with plastics.
Warning: Some pipe joint compounds or PTFE pastes may contain substances that could cause stress cracking in thermoplastic materials. Spears® recommends the use of Spears®
thread sealant that has been tested for compatibility with Spears® products. Choice of any other appropriate thread sealant is at the discretion of the installer.
Special Reinforced (SR) Thread Fittings: This patented fitting features all-plastic female thread construction that reduces problems associated with over-tightening of female plastic pipe threads. The external reinforcing collar is not just an added reinforcement ring, this unique precompression design compensates for expansion forces generated from tapered pipe thread joint make-up. Radial stress is reduced in normal installations and contained in severe over-tightening situations. The all-plastic internal construction provides for the maximum in chemical and corrosion benefits. Its solid construction and reliability make the SR our best transition design for all applications.
Brass Thread Fitting: This patented fitting features a molded-in-place brass thread with external reinforcing collar as an integral part of each fitting for superior strength. An internal form-compressed O-ring seal compensates for expansion and contraction variations between materials. Excellent as a metal-to-plastic transition adapter fitting.
Male Brass Thread Fitting: Developed for Copper Tube Size (CTS) hot-and-cold water distribution systems, this male brass thread alternative is the only metal thread design of its type that has the metal component lined with plastic for improved fitting construction and minimal exposure. Excellent for transition to female metal threads in a CTS system.
Gasket Sealed Thread Fittings: Also developed for Copper Tube Size (CTS) hot-and-cold water distribution systems, this female threaded fitting features all plastic internal construction for maximum corrosion resistance. The fitting incorporates straight-threads for mechanical connection, while sealing is accomplished through an internal elastomer gasket or O-ring against the pipe face. No sealants are used.
Except where otherwise specified, Spears® Transition Fittings/Materials are approved for use in potable water systems by NSF® International under ANSI/NSF® Standard 61, Drinking Water System Components - Health Effects.
CPVC Orange Fittings in this SPS-1 (4200 series part numbers) are approved by Underwriters Laboratories, FM Global, or LPCB for use in CPVC Fire Sprinkler Systems. When installed in these systems, installation must be made in accordance with Spears® publication FG-3, FlameGuard® CPVC Fire Sprinkler Products Installation Manual, and local codes. However, these fittings can also be used in many other types of installations. CPVC fittings may also be used on PVC pipe when installed using a quality CPVC solvent cement meeting the requirements of ASTM F 493, Standard Specification for Solvent Cements for Chlorinated Poly (Vinyl Chloride)(CPVC) Plastic Pipe and Fittings.
See Engineering Sourcebook SES-1 for specific product (i.e., Schedule 80 PVC Technical Information, Copper Tube Size (CTS) Technical Information, FlameGuard® CPVC Fire Sprinkler Products Technical Information, etc.).