NKM Manual Quick Connectors Pipe Leak Testing

Overview of NKM Manual Quick Connectors

The NKM series manual quick connectors are engineered for rapid sealing and connection of straight pipes and drilled holes during leak testing procedures. Designed for handle-driven operation, these connectors achieve a secure seal by compressing a front sealing ring against the inner wall of the test piece. A 90-degree rotation of the handle engages the seal, allowing test pressure to be applied immediately, while a reverse rotation releases the connection after testing is complete.

The NKM series supports both pressure and vacuum testing on straight pipes and drilled components, with a maximum working pressure of 3 bar under standard dry conditions. The connector body is constructed from anodized aluminum alloy, combining light weight with corrosion resistance, while the standard sealing ring is made of nitrile rubber (NBR). Alternative sealing materials are available upon request to accommodate specific test media or temperature requirements.

Key Features of NKM Manual Quick Connectors

Internal Sealing Mechanism

The NKM connector seals from the inside of the pipe or drilled hole. Its front sealing ring expands against the inner wall when the handle is engaged, creating a reliable seal without damaging the test piece surface or leaving contact marks. This internal sealing approach is suitable for applications where external clamping may not be feasible or where the outer surface must remain unmarked. The minimum leakage rate for standard products is 10⁻⁴ mbar·l/s (10⁻⁵ Pa·m³/s), with lower-leakage configurations available based on customer specifications and sample quality.

Handle-Driven Quick Connection

Operation requires no additional tools or external power source. The operator inserts the connector into the test piece, rotates the handle by 90 degrees to engage the internal seal, applies test pressure, and after completion rotates the handle back 90 degrees to release. This manual actuation makes the NKM series suitable for field testing, low-volume production lines, research and development laboratories, and environments where pneumatic or hydraulic actuation is not available. The sealing surface and the tested workpiece must be dry during operation; if the contact surface is contaminated with water or lubricants, the operating pressure must be limited to below 1 bar.

Wide Sealing Range with Self-Adaptive Ring

The NKM series comprises 25 standard models covering internal diameters from Φ9.5 mm to Φ34.4 mm, organized across three shape dimensions. Each model accommodates a 1 mm diameter tolerance range, and the self-adaptive sealing ring compensates for minor surface irregularities and dimensional variations within the specified range. Custom sizes can be manufactured for applications outside the standard range. All models use a G1/8″ inlet thread and are available with or without a matching plug (part numbers with suffix P).

Technical Specifications of NKM Manual Quick Connectors

Applications of NKM Manual Quick Connectors

NKM quick connectors are used in leak testing setups across automotive component manufacturing, plumbing and HVAC assembly, medical device production, and general industrial quality control. They are particularly suited for testing straight pipe sections, manifold ports, cast housing openings, and drilled holes in machined components. When ordering, business buyers should specify the part number, required pressure range, test medium and leakage rate, temperature range, space constraints, and a CAD drawing of the test piece to ensure proper model selection.

FAQ About NKM Manual Quick Connectors

What is the maximum working pressure of NKM connectors?

The maximum working pressure is 3 bar under standard dry conditions. If the sealing contact surface is wet or contaminated with lubricants, the operating pressure must be limited to below 1 bar to maintain seal integrity.

How do I operate the NKM quick connector?

Insert the connector into the test piece until it reaches the required insertion depth (Lmin), rotate the handle 90 degrees to engage the internal sealing ring, apply test pressure, and after testing rotate the handle back 90 degrees to release. No tools or external power source are required.

What sealing materials are available, and can custom sizes be produced?

The standard sealing ring is nitrile rubber (NBR). Alternative materials can be specified based on test medium compatibility and temperature requirements. The standard range covers Φ9.5 mm to Φ34.4 mm internal diameters; custom sizes outside this range can be manufactured according to customer specifications.

Can NKM connectors be used for vacuum (negative pressure) testing?

Yes, the NKM series supports both positive pressure and vacuum testing on straight pipes and drilled components. The internal sealing ring maintains a reliable seal under both pressure and vacuum conditions within the specified operating limits.