Refrigerant Press Tools: RLS & ZoomLock MAX Selection and Installation Guide
A refrigerant press tool joins compatible ACR copper tubing and manufactured refrigerant press fittings using a system-specific jaw. This guide focuses on choosing and using refrigerant press tooling, featuring the iCrimp IWS-0625RCF and IWS-0628ZMCF. Copper tube expansion and swaging are covered later as a complementary preparation method for specified brazed joints.
For line sets, heat-pump refrigerant piping and refrigeration service work, start with the fitting system, actual tube OD and required tool/jaw combination. Then plan the complete installation, inspection, leak test and evacuation workflow.
Shop iCrimp refrigerant press tools
Both kits are now available. Select by the refrigerant press fitting brand and series first, then check the tube outside diameter and included jaw sizes. RLS and ZoomLock MAX are different jaw configurations.
RLS-profile refrigerant press tool
IWS-0625RCF
US$349.97
8 jaw sizes: 1/4, 5/16, 3/8, 1/2, 5/8, 3/4, 7/8 and 1 in.
Choose for the specified RLS fitting application. For original ZoomLock, confirm the fitting part number first. Not for ZoomLock MAX.
Includes wrench, 22 mm socket, GO-only gauge and carrying case.
Shop IWS-0625RCF →
ZoomLock MAX / ZM-profile ACR press tool
IWS-0628ZMCF
US$319.97
7 jaw sizes: 1/4, 3/8, 1/2, 5/8, 3/4, 7/8 and 1-1/8 in.
Choose for the specified ZoomLock MAX application; confirm the exact series for >B< MaxiPro. Not for RLS or original ZoomLock.
Includes wrench, 22 mm socket and carrying case. Depth gauge is not included.
Shop IWS-0628ZMCF →Prices shown in USD; current price and availability are displayed on each product page.
Manual or compatible impact-wrench drive
Both tools offer manual wrench operation or compatible impact-wrench drive. The impact wrench, battery and charger are not included. Follow the model-specific drive settings, completion and release instructions; the LED indication does not replace inspection or leak testing.
These model recommendations describe IWISS's intended fitting applications, not third-party certification. Confirm the exact tool, jaw and fitting combination against current manufacturer requirements. Use the fitting-brand selection table below if your packaging only says “ZoomLock”.
Before you buy: original ZoomLock is NOT ZoomLock MAX
Identify the refrigerant PRESS FITTING brand and product series—not just the copper tube brand. Read the fitting and packaging markings, then check the part number and tube outside diameter. The word “ZoomLock” alone is not enough to select a jaw profile.
| Fitting brand / series on your job | iCrimp model to consider | Check before ordering |
|---|---|---|
| RLS / Rapid Locking System | IWS-0625RCF — RLS profile | 8 jaw sizes: 1/4, 5/16, 3/8, 1/2, 5/8, 3/4, 7/8 and 1 in. Not the ZoomLock MAX profile. |
| Original / legacy ZoomLock (not MAX) | RLS-profile selection route: IWS-0625RCF, after part-number confirmation | Original RLS-made ZoomLock fittings belong to the RLS family. Check the RLS cross-reference and send the exact fitting part number for confirmation. Do not select IWS-0628ZMCF simply because “ZoomLock” appears on the box. |
| Parker / Sporlan ZoomLock MAX | IWS-0628ZMCF — ZM profile | 7 jaw sizes: 1/4, 3/8, 1/2, 5/8, 3/4, 7/8 and 1-1/8 in. Not the original ZoomLock / RLS profile. |
| Conex Bänninger >B< MaxiPro | IWS-0628ZMCF — check the exact series | Listed in the IWISS ZM-model application specification. Confirm the regional fitting series, size and permitted tooling; do not assume every Conex product uses this profile. |
| ZoomLock PUSH | Neither press-tool kit | A push-to-connect system, not a press-jaw application. |
| Unmarked fitting / “ZoomLock” without a clear generation | Confirm before buying | Email clear fitting and packaging photos, part number, tube OD and country to sales@iwiss.com. |
Why the names cause confusion: RLS originally supplied fittings marketed as ZoomLock through Parker/Sporlan. RLS later sold under its own brand and announced the end of supply to Parker in August 2020. ZoomLock MAX is a distinct system; a shared historical brand name does not establish interchangeable jaws.
Use the manufacturer's current tooling requirements for the exact fitting. The model guidance above describes IWISS's intended application, not RLS, Parker or Conex Bänninger certification. Brand, series, jaw profile and size must all match.
Identification references: RLS brand history · Original ZoomLock / RLS part-number cross-reference · Parker ZoomLock MAX tooling guidance.
Pressing, swaging and flaring: three different operations
| Method | What the tool does | How the connection is completed | Typical selection question |
|---|---|---|---|
| Refrigerant press connection | Deforms a dedicated fitting with a matched jaw | The fitting's specified mechanical and sealing arrangement | Is this exact tool/jaw combination supported for this fitting system? |
| Tube expansion / swaging | Enlarges a tube end to receive another tube | The prescribed joining process, typically brazing for the applicable refrigeration installation | Can this tube temper, wall and OD be expanded to the required socket geometry? |
| Flaring | Forms a flared tube end | A matched flare nut and mating seat assembled to the equipment specification | Does the equipment require a flare connection and the specified flare geometry? |
Swaging is not drilling or deburring. The expander displaces the tube wall outward. Deburring removes the cutting burr; flaring forms a different joint geometry. Neither a PEX expander nor a wire-rope swager is a replacement for a refrigeration copper tube expander.
Start with the circuit, then the joining method
A heat-pump installation may have a hydronic water circuit and a separate refrigerant circuit. Record the circuit's medium, equipment model, tube specification and required connection type before selecting a tool. For refrigerant pressing, confirm the exact system and current tooling requirements; original RLS-made ZoomLock fittings follow the RLS-family identification route above, while ZoomLock MAX requires its own matching jaw profile.
The selected connection must satisfy the equipment and fitting instructions for pressure, temperature, refrigerant and oil where applicable. Tool force, drive torque and system pressure are different measurements: one cannot be converted into proof of another.
Refrigerant fitting systems: identify the product family first
These are three relevant refrigerant press fitting systems, not a universal compatibility list. Check the exact fitting part number, refrigerant/oil, tube specification, service conditions and regional documentation before choosing tooling.
| Manufacturer / system | Relevant application | What the installer must check |
|---|---|---|
| Parker — ZoomLock MAX | Press-to-connect fittings for refrigeration and air-conditioning refrigerant lines | Parker requires tools/jaws designed for ZoomLock MAX. Do not infer MAX compatibility from a legacy ZoomLock label or plumbing jaw. Consult its current tool/jaw and refrigerant compatibility information. |
| RLS — Rapid Locking System | Refrigerant press fittings | Use the RLS-approved tool and jaw combination for the fitting size. Follow its tube preparation, insertion and post-press inspection instructions; consult the current matrix. |
| Conex Bänninger — >B< MaxiPro | Air-conditioning and refrigeration, including the refrigerant side of heat pumps | Consult the regional MaxiPro tool/jaw compatibility chart, installation guide and refrigerant limits. MaxiPro is a distinct product family from the manufacturer's water-system fittings. |
A shared tool platform does not establish a shared jaw profile. Tool body, jaw/insert, fitting system and size must be checked together. A fitting's approval or warranty does not automatically approve a third-party tool. A manual or powered drive option does not, by itself, establish refrigerant-system compatibility.
Making a refrigerant press connection: the critical controls
- Confirm the complete system: identify the fitting family and verify tube OD, wall thickness, temper, refrigerant/oil suitability and the specified tool/jaw combination. Make the circuit safe before work.
- Prepare without contaminating the bore: cut square, deburr and prepare the sealing area using the fitting manufacturer's method. Check roundness and scratches; do not sand aggressively to disguise unsuitable tubing.
- Inspect and mark: inspect the fitting and sealing element. Use that system's depth chart or depth gauge, and mark the tube before inserting it fully. Do not substitute a water-fitting insertion depth.
- Align and press: support the line, recheck the insertion mark, seat the correct jaw at the specified location and complete the prescribed cycle. Allow enough room for both operation and release.
- Inspect by that system's rules: apply any specified post-press gauge or visual checks. A depth gauge confirms insertion preparation; it is not a finished-press gauge or a leak test. Inspection aids are not interchangeable between systems.
- Test and commission: complete the refrigerant system's prescribed pressure/leak test, evacuation and commissioning. Resolve an incomplete or suspect joint using the fitting manufacturer's procedure.
Flame-free pressing eliminates brazing at that press joint, not refrigerant-system testing. Nitrogen purging during brazing and nitrogen used for a subsequent pressure test serve different purposes. Do not read “no brazing purge needed” as permission to skip testing or evacuation.
Refrigeration reliability: control contamination as carefully as the joint
HVAC includes refrigeration as well as water-based heating and cooling. Refrigerant circuits add particular concerns: moisture, non-condensable gases, oil return, vibration and refrigerant-specific safety. A mechanically sound joint is only one part of a reliable installation.
Keep tubing clean, dry and closed until assembly
Use the specified refrigeration-grade tubing and protect its capped ends during storage and routing. Keep cuttings, dirt and water out of the bore. An open line exposed to rain or construction debris requires assessment and the prescribed corrective procedure; merely running the vacuum pump longer is not a substitute for cleaning contamination.
Separate nitrogen purging from pressure testing
Brazing purge flow and a pressure test serve different purposes. Use the regulated nitrogen setup and flow specified for brazing, with an appropriate outlet; never braze a closed pressurized section. After the joint cools, perform the separate prescribed test. Do not substitute oxygen or compressed air for dry nitrogen in a refrigerant-circuit test.
Inspect an expanded socket before applying heat
Check for a split lip, uneven expansion, wall damage and incorrect overlap. Compare fit with the joining specification rather than judging only whether one tube enters the other. Reject a damaged end instead of trying to fill a crack with brazing alloy. Follow the specified heating and filler procedure; surface appearance alone does not establish a sound internal joint.
Measure the system vacuum, not just the pump
Connect a suitable micron gauge where it measures the system, away from the pump as recommended by the instrument instructions. Verify that valve positions leave the gauge connected to the system when the pump is isolated for the prescribed standing/decay test. A gauge isolated with a hose may report that small volume rather than the installation.
A low reading while the pump is running is not a complete acceptance test. Evaluate the isolation reading and trend against the equipment procedure. Vacuum rise can involve leaks, remaining moisture, outgassing or the test setup; the curve alone does not identify the cause. Check hoses, seals, gauge condition and pump performance before condemning the pipework.
Plan for vibration, pipe routing and oil return
Use the equipment manufacturer's line sizing, length and elevation limits. Support piping so compressor vibration, rubbing and thermal movement do not load the joints. Follow the specified routing and oil-return design; do not add traps simply because another installation has them. A leak-free line can still cause poor operation if its piping design is wrong.
Use refrigerant-specific controls for A2L work
Identify the refrigerant from the equipment documentation. For R32 or another A2L refrigerant, follow that equipment's requirements for ventilation, ignition-source control, charge/room limitations and suitable service equipment. Use a compatible leak detector; never search for a leak with a flame. Do not bypass installed leak detection or mitigation functions. Refrigerant recovery and hot-work preparation must follow the specified procedure before opening or heating the circuit.
Questions refrigeration installers ask on site
Is a particular micron number enough to pass every installation?
No. Record the equipment's evacuation target, standing-test duration and allowable rise. Follow those requirements instead of applying a universal internet threshold. A pressure leak test and evacuation answer different questions, and both may be required.
The pressure dropped overnight. Does that prove there is a leak?
Investigate it. Temperature changes can affect pressure, and the test hoses or valves can also leak. Record ambient/pipe temperature and use the prescribed stabilization and evaluation method. Do not dismiss a drop as temperature without checking and meeting the acceptance criteria.
Can I use any soap solution to find a leak?
Use a leak-detection fluid compatible with the system and refrigerant, or the specified electronic method. Avoid chlorine-containing detergents where prohibited by the manufacturer. Follow the detector's calibration and operating instructions.
Can a larger expander head solve a tight fit?
No. Confirm the head, tube OD, temper and expansion sequence. Oversizing the socket can compromise joint clearance; forcing a connection can damage the tube. Re-prepare the end when it fails the specified geometry checks.
Record evidence before releasing the system
- Equipment/refrigerant identification, tube dimensions and joining method.
- Joint inspection, pressure-test medium, readings, time and temperature conditions.
- Evacuation target and achieved system reading, isolation duration and final reading.
- Required leak checks, charge record, valve/cap checks, insulation and operational commissioning results.
Use trained personnel and the equipment-specific instructions for commissioning. Keep refrigerant lines accessible until the required joint checks are complete.
Further technical reading for these checks
- Fieldpiece: correct vacuum-gauge use
- Copeland: cleaning and evacuation
- Copeland: refrigeration installation and service
- Daikin Applied: R32 equipment installation and maintenance example
The cited equipment documents apply to their own models. They illustrate the checks to look for in your equipment's current instructions, not settings to copy to every system.
Problems to catch before the system is closed up
| Observation | What to investigate | Next action |
|---|---|---|
| Tube moves away from its insertion mark during pressing | Support, alignment and insertion depth | Evaluate the joint under the fitting manufacturer's inspection/repair procedure. |
| Split or heavily distorted expanded tube mouth | Wrong head, unsuitable temper, over-expansion or damaged tube | Reject the damaged end and re-prepare sound tubing if permitted. |
| Expanded socket is loose or out of round | Head selection, expansion sequence and required joint clearance | Verify geometry before brazing; extra filler is not a substitute for correct fit. |
| Cutter will not accommodate the largest expansion size | Independent cutter and expander capacities | Use a suitable larger-OD cutter; do not force the included tool. |
Questions technicians ask
Does an expander make a flare for a mini-split connection?
No. Swaging and flaring form different shapes. If the equipment requires a flare, use a suitable flaring tool and follow its flare dimensions and assembly instructions.
Can I press a socket I formed with an expander?
An expanded bare tube end is not a manufactured press fitting. Do not treat it as one or use an ordinary press jaw to invent a connection method.
Does the size printed on a water-system jaw equal ACR tube OD?
Not necessarily. For example, North American 1/2-inch nominal copper water tube has a 5/8-inch OD; 1/2-inch ACR tubing has a 1/2-inch OD. Identify the sizing convention before ordering.
Which information should I send for a tool recommendation?
Email sales@iwiss.com with the application, joining method, tube OD/wall/temper, fitting brand and series if used, and a work-area photo. For a fleet or contractor team, include the sizes and expected workload.
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When the job calls for swaging instead of pressing
Tube expansion is a complementary capability for technicians who also make specified brazed connections. The following section covers that separate workflow; use it when the equipment and joining specification call for a swaged socket, not to prepare a tube end for a manufactured press fitting.
Making a swaged socket in refrigeration copper tubing
1. Confirm the tube can be expanded
Use tubing suitable for the tool and installation. Soft/annealed copper is the relevant starting point for these expander kits; check actual OD, wall thickness, temper and the tool instructions. Do not force hard-drawn or unsupported tubing onto an expander, and do not improvise field annealing where the equipment or installation specification does not permit it.
2. Cut, deburr and keep the bore clean
Use a cutter rated for the actual tube OD. Cut square without excessively crushing the end. Remove the internal and external burr as specified, keeping chips and debris out of the refrigerant circuit. Inspect for dents, ovality, scratches and contamination before expansion.
3. Select the head and form the socket
Choose the head for the tube's actual outside diameter, seat it as directed and operate the expander through the specified sequence. Use the tool's rotation function according to its instructions to distribute expansion. Do not use extra cycles to compensate for the wrong head or to enlarge the socket until the mating tube becomes loose.
4. Check socket depth, roundness and fit
The expanded section should accept the mating tube to the specified overlap without splitting, excessive thinning or a visibly distorted mouth. Check the required clearance for the approved joining procedure. A swaged socket can replace a separate coupling in suitable applications, but only when the resulting joint geometry and joining method meet the system requirements.
5. Complete the specified brazed joint
The expander has only formed the socket. Follow the equipment manufacturer's brazing procedure, including appropriate filler, heat control and dry-nitrogen purging to limit internal oxidation. Keep the purge outlet open as prescribed; never heat a closed, pressurized section. Refrigerant must be properly recovered and the circuit made safe before hot work. Flammable refrigerants require the equipment-specific service procedure.
6. Test, evacuate and commission
After joining and cooling, complete the prescribed pressure/leak test, then evacuation and commissioning. Do not use oxygen for pressure testing. Test pressure, holding time, evacuation target and acceptance criteria come from the equipment and system documentation—not a generic tool article. A vacuum reading alone is not a substitute for the required leak test.
Complementary tools: iCrimp auto-rotation copper tube expanders
Why the rotating expansion head matters
IWISS developed the automatic head-rotation design used in these expansion tools to help distribute forming around the tube circumference. The IWS-3858C listing specifies a 30-degree rotation after each expansion operation. This design supports a more even socket and is intended to reduce uneven local deformation when the tool is operated correctly.
Uniform socket preparation supports joint reliability. It can help reduce preparation defects that contribute to a poor connection, but rotation alone does not make a leak-tight joint. Tube condition, socket geometry, overlap, brazing quality and the specified leak test remain essential. In a refrigerant circuit, the relevant concern is refrigerant leakage—not simply water leakage.
The following products form swaged sockets in suitable tubing. They are not refrigerant press tools and do not create a sealed connection without the specified subsequent joining process.
IWS-3814C: refrigeration copper tube expansion
Listed expansion sizes: 3/8, 1/2, 5/8, 3/4, 7/8, 1, 1-1/8 and 1-1/4 inches. The kit includes an auto-rotation expander, cutter and deburring tool. Use on compatible soft tubing and verify wall thickness, temper and head selection.
IWS-3858C: expansion through 1-5/8 inches
Listed expansion sizes: 3/8, 1/2, 5/8, 3/4, 7/8, 1, 1-1/8, 1-1/4, 1-3/8, 1-1/2 and 1-5/8 inches. Includes an auto-rotation expander, cutter and deburring tool. The included cutter is rated only through 1-1/4-inch OD: larger tubing needs a separately matched cutter.
Buy to fill a capability gap. The expander kits already include cutting and deburring tools. Add preparation tools only when you need a larger capacity, different access or replacement equipment. For a refrigerant press-tool inquiry, provide the exact fitting family and size so the required system-specific tooling can be checked separately.
Refrigerant fitting manufacturer references
- Parker ZoomLock MAX: installation, tool/jaw and refrigerant compatibility resources
- Parker ZoomLock MAX Catalog K-3: system-specific installation instructions
- RLS installation instructions
- RLS tool and jaw compatibility matrix
- Conex Bänninger >B< MaxiPro: US installation and compatibility resources
- Copper Development Association: Copper Tube Handbook
These references describe their respective systems and installation principles; they do not constitute third-party approval of an iCrimp tool. Use the current instructions for your exact fitting, tube and tool combination.
Additional installation reference: Daikin FXDQ installation manual—refrigerant piping and nitrogen during brazing. This is an example of equipment-specific instructions, not a universal procedure for other equipment.