Complete Guide to Hydraulic Press Tool Pipe & Jaw Compatibility

1. Five Mainstream Piping Categories

1.1 CTS Copper Pipe (Mainstay for Residential Water Supply)

CTS stands for Copper Tube Size, the most common metal pipe for hot and cold water and HVAC in homes, apartments, and commercial shops. Copper is soft and easily crimped to form a reliable mechanical seal.

Compatible jaw type: VUS standard crimping jaws. Common sizes include 1/2", 3/4", 1", 1-1/4", 1-1/2", and 2". One set of VUS jaws covers all CTS copper pipes of the same size.

Additional information: CTS copper pipes are subdivided into three wall thickness grades: Type K (thickest, used for underground water supply), Type L (medium thickness, most common for hot and cold water), and Type M (thinnest, used in low-pressure scenarios such as drainage or some HVAC systems).

Our 22KN Compact Series :

SP-12522 – Identical 22KN power for 1" max CTS copper and small-bore stainless pipe. Built for mobile field plumbers, the included shoulder strap eases transport between service calls.

 Product Link:

https://swansofthyd.com/products/propress-tool-for-copper-pipe-with-22kn-hydraulic-crimping-tool-pro-press-copper-crimper-tool-kit-12522?utm_source=copyToPasteBoard&utm_medium=product-links&utm_content=web

1.2 Viega ProPress Stainless Steel Pipe (Commercial & Industrial Heavy Duty)

Stainless steel pipes have thicker walls and much higher hardness than copper, with higher sealing and pressure resistance standards. They are widely used in high-rise buildings, commercial kitchens, factories, and fire-fighting water supply systems.

Compatible jaw type: VUS crimping jaws (same as CTS copper). A set of jaws can be used interchangeably for the same inch designation.

Keep in mind: Thick-walled stainless steel requires greater crimping force to achieve a complete seal. Small diameter pipes of 1 inch and below can use light-duty hydraulic jaws, while large diameters of 1-1/4 inches and above must use heavy-duty high-pressure equipment (32KN and above); otherwise, insufficient crimping may occur, posing a risk of leakage.

Our 32KN Heavy-Duty Series:

SP-20032-4Jaws – Construction-grade unit for all-day commercial plumbing. The large 166ml hydraulic oil tank reduces maintenance downtime for all-day jobs. Shoulder strap reduces fatigue during multi-story installations.

Product Link:

https://swansofthyd.com/products/propress-tool-copper-pipe-crimping-tool-pro-press-copper-crimper-tool-with-us-standard-jaws-20032-4j?utm_source=copyToPasteBoard&utm_medium=product-links&utm_content=web

SP-20032-6Jaws – Ultimate all-in-one solution for full-service contractors. Preloaded with six VUS jaw sizes covering every common CTS copper and Viega stainless dimension from 1/2" to 2". No extra jaw purchases needed for any copper or stainless pipe project.

Product Link:

https://swansofthyd.com/products/pro-press-tool-for-copper-pipes-32kn-propress-tool-kit-6-us-standard-jaws-20032-6j?utm_source=copyToPasteBoard&utm_medium=product-links&utm_content=web

Note: Viega ProPress stainless steel follows CTS sizing, so jaws are fully interchangeable with standard CTS copper.

1.3 RLS Piping (For Air Conditioning, Refrigeration & High-Pressure Systems)

RLS stands for Rapid Locking System. It is a press connection design primarily used for air conditioning, refrigeration, heat pumps, and high-pressure cooling lines. This system is not used for regular household water supply. Instead, it is built for refrigerant and high-pressure fluid lines, where even small leaks can cause the whole system to fail.

Key Difference: RLS uses a unique double-indentation crimp profile on its fittings. It requires exclusive RLS press jaws to work correctly. Standard VUS jaws (for CTS copper and stainless steel) do not match this profile and cannot create a safe seal.

During installation, you must use RLS-specific jaws and RLS fittings together. The double-indentation crimp provides a very strong, leak-proof seal that can handle high pressure safely.

Warning: Never use VUS, IPS, or any standard plumbing press jaws on RLS fittings. Doing so will cause refrigerant leaks, incomplete seals, or equipment damage.

1.4 IPS Piping (For HVAC, Gas & Industrial Piping)

IPS stands for Iron Pipe Size, a dimensional system based on the outer diameter of old-style cast iron pipes, widely used in central air conditioning water circulation, gas transmission, and large industrial equipment piping.

Key Difference: For the same inch designation, the outer diameter of IPS pipes is larger than that of CTS copper pipes; therefore, VUS crimping jaws are not interchangeable.

During installation, IPS-specific crimping jaws, along with matching crimp rings and fittings, must be purchased separately. These accessories are incompatible with the CTS/Viega system.

Note: Even in emergency situations, do not attempt to crimp IPS pipes with VUS jaws, as this may result in seal failure or even damage to the fittings.

1.5 PEX Cross-linked Polyethylene Pipe (Flexible Home Water Pipe)

PEX is a flexible plastic hot and cold water pipe, widely used in new home renovations and old home refurbishments. It's important to note that PEX and metal pipes belong to two completely different installation systems; metal hydraulic pipe crimping tools (like ProPress tools) are not suitable for PEX.

However, within PEX, there are two main installation methods:

First: Expansion System – The most common method. During installation, a specialized expansion tool (electric or manual) is used to widen the PEX pipe opening. After fitting, the material's "shape memory" automatically retracts and locks in place. This method is completely unrelated to hydraulic compression sealing and does not require copper ring crimping.

Second: Crimp System. During installation, a manual or battery-powered PEX-specific crimping tool is used to press a copper or stainless steel ring against the outer wall of the PEX pipe to form a seal.

Here are the key distinctions:

PEX crimping tools are manual or battery-powered mechanical devices, completely different from hydraulic press tools.

Metal hydraulic press tools (whether 22KN or 32KN) cannot be used to crimp the copper rings of PEX.

PEX crimping leaves a hexagonal or circular indentation, while hydraulic press tools leave a full circular indentation on metal pipes.

Conclusion: Conventional hydraulic press tools are not suitable for PEX installation. Whether you are using expansion or crimping PEX, you need to purchase dedicated PEX installation tools (expanders or PEX crimping tools). Forcibly using VUS metal jaws to crimp PEX will flatten the pipe, cause cracks, and lead to long-term leaks; this is absolutely prohibited.

2. Hydraulic Press Tool Pressure Ratings & Compatibility Logic

2.1 22KN Light-Duty Equipment

Compatibility Range: CTS copper pipe up to 1" in diameter, and Viega ProPress stainless steel pipe up to 1" in diameter.

Unsuitable for: Metal pipes 1-1/4" and larger; not compatible with IPS piping or standard PEX tubing.

Applicable Scenarios: Home DIY, small-scale repair work, occasional crimping of copper and small stainless steel pipes.

2.2 32KN Heavy-Duty High-Pressure Equipment

Compatibility Range: Can crimp CTS copper pipe up to 2" and Viega ProPress stainless steel pipe up to 2" (including thick-wall versions).

Extended Capabilities: With optional IPS-specific jaws, it can also handle IPS piping for HVAC, gas, and industrial systems.

Limitations: Even with sufficient force, standard VUS jaws are not compatible with PEX tubing. PEX requires dedicated expansion or crimp tools.

Applicable Scenarios: The primary choice for professional plumbers and HVAC engineering teams; ideal for daily, long-duration, large-diameter, high-intensity construction.

Additional Suggestion: If you regularly work with stainless steel pipes larger than 1-1/4", we recommend using the 32KN model directly. Do not force crimping with a 22KN tool — it will not create a reliable seal and may damage the jaws or fittings.

3. Key Points to Avoid Regarding Jaw Size Compatibility

VUS jaws: Specifically designed for CTS copper and Viega stainless steel pipes. They are the standard for the North American ProPress system. Do not use them outside this range.

IPS dedicated jaws: Used for HVAC, gas, and industrial piping. These are separately purchased accessories and are completely incompatible with VUS sizes.

RLS jaws: Designed for ACR refrigeration copper tubing, commonly used in commercial refrigeration, data centers, hospitals, and other scenarios where open flames are prohibited.

RLS jaws use ACR sizing (e.g., 1/4", 3/8", 1/2"), which is different from the CTS/IPS sizing system and cannot be interchanged with VUS or IPS jaws.

PEX tools: Standard metal jaws have no tooling compatible with PEX. Whether using expansion or crimping PEX, PEX-specific tools (expanders or PEX crimping tools) must be used, completely separate from the metal hydraulic jaw system.

Mixing jaw sizes for different pipe diameters is strictly prohibited:

Using a small jaw on a large pipe → the pipe wall will crack.

Using a large jaw on a small pipe → there will be gaps in the seal, leading to slow leakage after water is applied.

Both of these situations will fail U.S. piping safety inspections (UPC/IPC standards).

4. Tool Maintenance & Safety Standards

Jaw Maintenance: Over time, the mating surfaces of crimping jaws may wear or deform. Regular inspection, cleaning, and application of anti-rust oil are recommended. Use original or certified jaws to avoid uneven crimping force due to dimensional deviations from aftermarket parts.

Sealing Ring / Pressure Ring Compatibility: Crimping fittings typically have built-in EPDM sealing rings or pressure rings. Different brands of sealing rings may have compatibility differences; try to use the same brand for the same project.

On-site Verification: Most U.S. states require crimping of water or gas pipelines to comply with UPC (Uniform Plumbing Code) or IPC (International Plumbing Code) standards. Some projects will check whether the crimping tools are within their valid calibration period. After crimping, visually inspect the crimp marks for completeness and straightness.

5. Quick Reference for Tool Selection by Scenario

Home repair of copper water pipes: A 22KN light-duty hydraulic press tool + VUS basic jaw set will meet most needs.

Commercial stainless steel water supply projects: Prioritize 32KN heavy-duty equipment, especially for large-diameter pipes, as it offers significantly better sealing stability.

HVAC (Heating, Ventilation, Air Conditioning) IPS piping installation: Use a 32KN unit, and purchase a separate set of IPS-specific crimping jaws.

Whole-house PEX flexible water pipe retrofitting: Directly use PEX expansion installation tools or PEX-specific crimping tools; do not attempt to use metal hydraulic press tools.