Guide to threaded PEEK adapters for joining different tubing dimensions
Biotech Fluidics provide a comprehensive range of threaded PEEK adapters for connecting tubing of various diameters using fittings of different thread designs. Some of these versatile adapters are manufactured with two female ends for easy connection of two tubing ends even when they have vastly different outer diameters. A complete tubing joint consists of a threaded PEEK adapter with female-to-female layout, plus male fitting assemblies with nut and ferrule from any of the compatible fitting systems, for example the Flangeless™ or Fingertight fittings.
The range of threaded PEEK adapters with female-to-female layout covers English threaded port designs of coned 10-32, and flat-bottom 1/4-28, 5/16-24, & 1/2-20, in addition to metric threaded flat-bottom M6x1. These adapters will thus enable convenient connection of the frequently used tubing sizes of 1/16”, 1/8”, & 3/16” OD, with both smaller and larger tubing outer diameters. The adapters cover tubing sizes ranging from 1.0 mm OD or less (down to 70 µm) using tubing sleeves, up to large bore tubing of 5/16” (7.9 mm) & 1/4″ (6.4 mm) OD. These threaded adapters are typically pressure resistant up to 1,000 psi (69 bar), except for the adapters intended for large bore tubing, which are specified up to 250 psi (17 bar).
The table below contains a convenient overview of the available IDEX threaded PEEK adapters with female-to-female designs for direct connection of two tubing ends of different diameters. Each adapter is listed with the port designs at its two ends, together with a list of the tubing outer diameters that this port can accommodate using the compatible fittings systems. Underlined tubing dimensions, indicates that the adapter is delivered with a fitting assembly for that particular size.
| Part No.* | Narrow port design** | Wide port design** | Narrow tubing OD | Wide tubing OD |
|---|---|---|---|---|
| P-626 | 10-32 C | M6x1 FB | 1/32”, 1/16”, plus 1.0 mm to 70 µm using tubing sleeves | 1/32”, 1/16”, 1/8”, 1.8 mm, 2.0 mm, 2.5 mm, 3.0 mm |
| P-627 | 10-32 C | 1/4-28 FB | 1/32”, 1/16”, plus 1.0 mm to 70 µm using tubing sleeves | 1/32”, 1/16”, 1/8”, 1.8 mm, 2.0 mm, 2.5 mm, 3.0 mm |
| P-135 | 1/4-28 FB | 5/16-24 FB | 1/32”, 1/16”, 1/8”, 1.8 mm, 2.0 mm, 2.5 mm, 3.0 mm | 1/16”, 1/8”, 3/16”, 4.0 mm |
| U-665 | 1/4-28 FB | 1/2-20 FB | 1/32”, 1/16”, 1/8”, 1.8 mm, 2.0 mm, 2.5 mm, 3.0 mm | 1/4", 5/16” |
| U-659 | 5/16-24 FB | 1/2-20 FB | 1/16”, 1/8”, 3/16”, 4.0 mm | 1/4", 5/16” |
| **C = Coned, FB = Flat-Bottom | ||||
From this summary it also becomes apparent that to join tubing dimensions of rather similar outer diameters, no adapter will be required. Instead, a simpler threaded union together with the appropriate fitting system and ferrules would be sufficient.
Adapters with coned 10-32 female ports (P-626 & P-627) are compatible with all the different IDEX fitting systems for such designs, although not recommended for stainless-steel fittings. They are particularly suitable for the one-piece and two-piece Fingertight fitting systems, alternatively the range of NanoTight™ fittings if tubing sleeves are used. To facilitate assembly, these two adapters are delivered with a F-300 two-piece Fingertight fitting including the F-142 PEEK ferrule.
The adapters that contain a flat-bottom 1/2-20 female port (U-659 & U-665) can accommodate tubing dimensions with outer diameters of 1/4″ & 5/16”. These adapters are conveniently supplied with the large bore Flangeless™ fittings U-655 with U-650 ferrule for 1/4″ OD tubing.
All the adapters with one port of 1/4-28 or M6x1 can accommodate a wide range of tubing dimensions due to the comprehensive range of ferrules in the Super Flangeless™ and Flangeless™ fitting systems. Together these can accommodate tubing dimensions of 1/32”, 1/16”, 1/8”, 1.8 mm, 2.0 mm, 2.5 mm, & 3.0 mm.
The two adapters equipped with 5/16-24 flat-bottom ports (P-135 & U-659) can connect tubing with outer diameters of 3/16” & 4.0 mm, plus the common dimensions of 1/16” & 1/8” OD, using the Super Flangeless™ and Flangeless™ fitting systems.
Consult the product webpages for additional variants of threaded adapters and unions that can simplify connection of different tubing dimensions or threaded port designs. Note that several other variants of adapters are available, for example for HPLC and capillary systems, and for soft-walled tubing that can use barbed fittings, but this is beyond the scope of this text. Contact Biotech Fluidics for expert guidance to the most suitable solution for your fluidic system.
