General Information About A-Lok® Fittings
Parker A-LOK® and CPI™ tube fittings ensure leak-free and reliable connections with a very long service life. Sealing is guaranteed even under vibration load and high temperature changes.
They are used in the areas of process, power, control, and analysis technology in various industries, such as the chemical and petrochemical industries, power generation, and in pulp and paper mills.
They are suitable for different tube wall thicknesses and are available in a wide selection of sizes, materials, and ISO or ANSI thread connections, and are approved for repeated reassembly.
- Two-ferrule fitting consists of four precision components
- Leak-free and secure connections for high-pressure and vacuum applications
- Vibration-resistant and no twisting of the fitting during assembly
- Single-ferrule fitting for high reliability and leak-free operation
- Especially recommended for high temperature changes
- Suitable for repeated assembly, easy disassembly with minimal tube twisting
The Parker A-LOK® two-ferrule fitting consists of four precision components that guarantee secure, leak-free connections in high-pressure and vacuum applications, even under vibration load.
Parker instrumentation tube fittings are delivered completely assembled and ready for use. When tightening the nut, the front ferrule is pressed onto the tube by the inner cone of the body and plastically deforms it; this results in a pressure- and vacuum-tight non-positive connection between the tube and the fitting. The rear ferrule is pressed into the tube by the cone of the front ferrule, creating a firm mechanical hold of the tube.
Properties
Parker A-LOK® tube fittings have been specially developed for use in instrumentation, process and control technology, analytical devices, and equipment in the chemical and petrochemical industries, power generation, and in paper mills.
Materials
A-LOK® fittings are standardly available in 316 stainless steel and are provided with material batch numbers. The following other standard materials are also available: carbon steel, brass, aluminum, Monel, Hastelloy C®, Incolloy, titanium, 6Mo, Inconel 625, and 825. Straight fittings are manufactured from cold-drawn bar stock and shaped bodies from fine-grained forgings. For nuclear and other critical applications, A-LOK® stainless steel fittings are available with material certificates (EN 10204, 3.1b).
Threaded Fittings/Adapters
The fittings are available with a large selection of ISO and ANSI thread connections.
Tube Selection
Our tube fittings can be used with a wide selection of tube materials and wall thicknesses. Tube and fitting material should be selected according to the flow medium. Due to the thermal expansion properties and chemical stability, the tube should be made of the same material as the fitting.
No Torque
The A-LOK® ferrule design ensures that any assembly and reassembly forces are transmitted axially onto the tube. Since no radial movement of the tube occurs, the tube is not stressed. The mechanical integrity of the tube is maintained.
Re-usability
During assembly, no radial forces are generated that could lead to the deformation of ferrules or union nuts. This ensures easy disassembly of the nut and a high number of reassemblies.
Sealing
Extensive tests and over 4 decades of experience in the manufacture of quality tube fittings ensure consistently reliable connections with fittings.
Assembly, Reassembly, and Inspectability
The assembly and reassembly instructions for Parker A-LOK® tube fittings, as well as the inspection of the assembled fitting with the help of inspection gauges, are described on page 74 of this catalog.
Pressure Ratings and Tube Selection
Information on operating pressures for A-LOK® tube connections can be found in the “Instrument Tubing Selection Guide”, which is located in your Instrumentation master catalog or in the “Parker Instrument Tube Fitting Installation Manual” (Catalog BUL4200-B4).
When combining a Parker A-LOK® fitting with a screw-in or screw-on thread, these threads may lead to a reduction in the maximum operating pressure of the connection. Pressure ratings for Parker threaded fittings can be found in Catalog CAT4260-P/W
(Threaded and Welded Fittings).
