The Tunable Wide-Tolerance Connector for Tubes and Bores

The FasTest EZ Connect ZN is a lever-actuated internal seal-only connector for holes, bores, and tube ends, rated from vacuum up to 50 psi. Its wide-tolerance design means it seals across a range rather than requiring a precise fit to each part — and it covers an unusually broad set of geometries: holes and bores plus straight, expanded, flared, beaded, barbed, formed, and swaged tube.

What makes the EZ Connect ZN unusual is that it is tunable. An adjustment ring sets the seal preload, and a lockable collar holds that setting so every subsequent connection applies the same sealing pressure. Preload is normally a fixed compromise designed into a connector: too much and the seal wears out early, too little and it leaks. Being able to dial it in for the application and lock it is what “maximise seal life” means in practice — the seal is compressed exactly as much as the job requires and no more.

The FasTest EZ Connect ZN uses a high-flow design, which matters because it is built as much for fluid filling and flushing as for testing. It can also be quickly adapted for plug-style applications, so the same tool that flows through one port can blank off another — useful on assemblies where several ports must be sealed and only one carries flow.

Quick-change seal sets let one tool body connect to multiple sizes of tubing and make field maintenance straightforward, so a worn seal is a quick swap rather than a tool returned to service. The ZN is the internal seal-only member of the FasTest EZ Connect™ family, alongside the ZGN for internal threaded connections and the ZF for external tube features.

The Problem the FasTest EZ Connect ZN Solves

Low-pressure fluid handling and testing across a varied part population creates problems that a precision-fit connector handles badly:

• Fixed preload is a hidden cost: Most connectors have their seal compression designed in and unchangeable. Too much preload and seals wear out early, driving consumable cost and downtime; too little and the connection leaks. Neither is adjustable after the fact.
• Tube sizes vary across a line: A precision-fit connector serves one tube size. Covering a range means buying, storing, and swapping between multiple connectors — and creates opportunities to grab the wrong one.
• Filling and flushing need flow, not just a seal: For fluid filling and flushing, a restrictive connector becomes the bottleneck in the process regardless of how well it seals.
• Some ports need blanking, not flow: Assemblies frequently need several ports sealed while only one carries fluid, which normally means stocking separate plugs alongside the connectors.

The FasTest EZ Connect ZN answers each: an adjustment ring and lockable collar let preload be tuned and held, quick-change seal sets cover multiple tube sizes from one body, a high-flow design suits filling and flushing, and the same tool adapts to plug-style use.

Key Features 

Adjustment Ring Sets Preload and Maximises Seal Life

The adjustment ring lets the operator set how much the seal is preloaded before connecting. That single control addresses a trade-off most connectors resolve permanently at the design stage: preload the seal heavily and it seals reliably but wears quickly; preload it lightly and it lasts longer but risks leaking. Because the FasTest EZ Connect ZN lets preload be matched to the application, the seal is compressed exactly as much as the work requires — which is what extends its service life and reduces consumable cost across a fleet of tools.

Lockable Collar for Consistent Sealing Pressure

Setting preload only helps if the setting holds, which is what the lockable collar does. Once the adjustment ring is set for the application, the collar locks it so every subsequent connection applies the same sealing pressure regardless of operator. Together the ring and the collar make the EZ Connect ZN a set-once, repeat-thereafter tool — tuned for the job, then consistent across the production run.

High-Flow Design, Quickly Adapted for Plug-Style Applications

The FasTest EZ Connect ZN is built with a high-flow design, which matters because it is designed for fluid filling and flushing as much as for pressure and vacuum testing — applications where a restrictive connector becomes the bottleneck. The same tool can also be quickly adapted for plug-style applications, blanking off a port rather than flowing through it. On an assembly where several ports must be sealed and only one carries fluid, that means one tool type instead of two.

Quick-Change Seal Sets for Multiple Tube Sizes

Quick-change seal sets allow a single EZ Connect ZN body to connect to multiple sizes of tubing, and they make field maintenance straightforward. Changing a worn seal or moving to a different tube size is a seal-set swap rather than a different tool, which reduces both tooling inventory and the downtime involved in keeping a line running.

Technical Specifications

Where the FasTest EZ Connect ZN Is Used

Fluid Filling and Flushing

The high-flow design makes the FasTest EZ Connect ZN well suited to filling and flushing operations, where throughput depends on how much fluid the connection will pass. Its wide-tolerance seal connects quickly to varied tube ends without a precise fit, keeping the fill or flush step off the critical path.

Low-Pressure Leak and Vacuum Testing

For pressure and vacuum testing up to the ZN’s rating, the tunable preload gives a seal matched to the application — firm enough to hold, light enough to last. The lockable collar then keeps that sealing pressure consistent across the production run, which is what makes low-pressure test results repeatable.

Mixed Tube-Size Production Lines

Lines handling several tube sizes benefit most from the quick-change seal sets: one EZ Connect ZN body covers the range, so changeover is a seal swap rather than a tool change. Combined with coverage of eight different bore and tube geometries, it replaces a set of size-specific connectors with a single tool.

Plug-Style Port Blanking

Because the FasTest EZ Connect ZN can be quickly adapted for plug-style applications, the same tooling that makes the flow connection can blank off the other ports on an assembly — avoiding a separate inventory of plugs and keeping the station standardised on one connector family.

FasTest EZ Connect ZN vs. a Precision-Fit Internal Connector

Frequently Asked Questions

Q: What is the FasTest EZ Connect ZN?

A: The FasTest EZ Connect ZN is a lever-actuated internal seal-only connector for holes, bores, and tube ends, rated from vacuum up to 50 psi. Its wide-tolerance design seals across a range rather than requiring a precise fit, and an adjustment ring lets the seal preload be tuned for the application.

Q: What does the EZ Connect ZN connect to?

A: Holes and bores, plus straight, expanded, flared, beaded, barbed, formed, and swaged tube — eight geometries in one connector, sealing internally with no fitting to install.

Q: What does the adjustment ring do?

A: It sets the seal preload — how much the seal is compressed before connecting. Most connectors fix this at the design stage, which forces a compromise: heavy preload seals reliably but wears the seal quickly, light preload lasts longer but risks leaking. Being able to set it for the application is what maximises seal life.

Q: What does the lockable collar do?

A: It locks the adjustment ring setting so every connection applies the same sealing pressure, regardless of operator. The ring and collar work as a pair: set the preload once for the application, lock it, and the tool repeats that setting across the production run.

Q: What is the pressure rating of the EZ Connect ZN?

A: Up to 50 psi. It is a low-pressure, high-flow connector designed for fluid filling and flushing as well as pressure and vacuum testing. Confirm the exact rating for your application with FasTest.

Q: Can the EZ Connect ZN be used as a plug?

A: Yes — the high-flow design can be quickly adapted for plug-style applications, so the same tool can blank off a port rather than flowing through it. On assemblies where several ports need sealing and only one carries fluid, that removes the need for a separate plug inventory.

Q: How does the EZ Connect ZN connect to different tube sizes?

A: Through quick-change seal sets. One tool body accepts different seal sets to cover multiple sizes of tubing, so changing size is a seal swap rather than a tool change — which also makes field maintenance straightforward.

Q: What is the difference between the EZ Connect ZN and the ZGN?

A: The ZN is a wide-tolerance seal-only connector for tubes and bores at up to 50 psi, with tunable preload and a high-flow design. The ZGN is a wide-tolerance threaded connector for internal threads — NPT, SAE, BSPP/BSPT, metric — rated to 300 psi in its pneumatic version. Choose the ZN for seal-only connections to tubes and bores, and the ZGN for internal threads.

Q: What are the FasTest EZ Connect tools?

A: The EZ Connect™ tools are a family of wide-tolerance FasTest connectors built to connect quickly across a range of sizes without precise alignment. The family comprises the ZN (internal seal-only for tubes and bores), the ZGN (internal wide-tolerance threaded), and the ZF (external wide-tolerance connections for tube features).

Q: What is the EZ Connect ZN used for?

A: Pressure testing, vacuum testing, fluid filling, and fluid flushing — particularly on lines handling multiple tube sizes, where the wide-tolerance seal and quick-change seal sets let one tool cover the range.