A-Lok – leak-free twin ferrule fitting for precise, secure instrumentation

A-Lok instrumentation fittings from Parker Hannifin are designed for precise, leak-free connections in systems with stringent demands for safety and reliability. With a twin ferrule design and high-quality materials, A-Lok is used widely within instrumentation, process control and hydraulics – particularly in industries such as oil and gas, chemicals and energy.

What is an A-Lok fitting?

A-Lok is Parker's own range of twin ferrule fittings, ensuring a strong, tight and vibration-resistant tube connection. The fitting consists of a body, a front ferrule and a back ferrule which, when tightened correctly, deform in a controlled manner around the tube to create a metal-to-metal seal.

Benefits of the A-Lok system:

Leak-free sealing, even under high pressure and temperature fluctuations.
Easy assembly and reassembly without loss of tightness.
Corrosion-resistant materials such as 316 stainless steel, titanium and 6MO.
Suitable for both gases and liquids in aggressive environments.

Please note: To ensure maximum tightness and operational reliability, the tube must be compatible with the fitting material and comply with the manufacturer's requirements for hardness and surface quality.

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Applications

A-Lok fittings are developed for use in:

Instrumentation and measuring systems.
Process and control plants.
Sampling and analysis equipment.
High-pressure hydraulic systems.
Offshore and energy installations.

Their versatility and robustness make them an obvious choice where system stability and leak-free operation are critical.

Materials, sizes and pressure ratings

A-Lok fittings are available in a wide selection to suit different applications:

Materials: 316 stainless steel (standard), brass, titanium, 6MO and more.
Sizes: From 1/16” to 2” (or metric sizes as required).
Variants: Straight, elbow, tees, crosses and custom designs.
Working pressure: Up to 16,800 PSI (depending on dimension and material).

Certification and traceability

All A-Lok fittings can be supplied with material certificates (EN 10204 3.1), ensuring full traceability and documented quality. This makes them well suited to installations subject to documentation requirements and to certified installations.

Access to Parker's entire A-Lok range

At Hymatik we keep a good selection of Parker A-Lok fittings physically in stock in our store, making us one of the few places in Denmark where you can get the products straight away. In addition, we have access to Parker's entire product programme, so we can source even the most specialised variants.

You are always welcome to contact us for help or advice on material selection, pressure ratings and applications.