Where it fits
These fittings are injection-moulded entirely from PFA, inside and out, with no metal anywhere on the wetted surface. They go on semiconductor wet-process ultrapure lines, small-bore branches of chemical delivery systems and display and solar wet-process lines, handling branching, turns and size changes on 3/4" tubing.
Compared with the PFA-lined Tri-Clamp fittings on this site, the difference is not chemical resistance, since both are fluoropolymer-wetted, but construction. Lined fittings rely on a 316L shell for mechanical strength and standard Tri-Clamp ends; moulded fittings take the metal out altogether and gain a completely metal-free part you can see through.
Key characteristics
- Injection-moulded PFA throughout, with no metal on the wetted surface and no interface between a lining and a shell.
- Translucent milky white, so fluid, bubbles or debris inside can be seen directly.
- Three configurations, tee, 90° elbow and reducer, in 3/4"; design temperature -30 to +150 °C.
- The PFA resin can be specified as an ultra-pure grade from a leading international producer or a cost-effective high-purity grade; material certificates are available.
The weak point of a lined part is the interface between lining and shell: a strongly permeating chemical that works through the lining over time attacks the metal behind it. A moulded part has no such interface, and on sections sensitive to metal background that is its core value. For how metal extractables are assessed, see metal extractables testing by ICP-MS.
Choosing between options
| Item | Injection-moulded PFA fittings (this series) | PFA-lined Tri-Clamp fittings |
|---|---|---|
| Construction | All PFA, no metal | 316L stainless body lined with PFA |
| Sizes | 3/4" | DN15 – DN50 |
| Connection | Plain tube ends, joined to suit your line | Tri-Clamp, designed to the BPE standard |
| Design pressure | Confirm at enquiry | Vacuum to 1.0 MPa (at 20 °C) |
| Design temperature | -30 to +150 °C | -30 to +150 °C |
| See-through | Translucent, fluid visible | No (a sight-glass configuration is offered) |
| Choose it when | Small-bore sections that must be completely metal-free | Larger lines that need mechanical strength and standard connections |
The reducer has a 3/4" large end; ask sales for the small-end size. The ends are plain tube and the joining method follows your line, so describe the tubing and how it is joined at enquiry.
Operation & change-out
An all-plastic fitting has no metal shell to share external loads, so pipe weight and thermal movement must be taken by racks and supports; do not let the fitting carry bending or pulling loads. PFA expands more with heat than metal does, so allow for movement on long runs.
No pressure rating is published yet, so confirm the actual operating pressure and temperature at enquiry. After installation, flush with water or ultrapure water and check the joints for leaks before introducing chemicals.