Press for best practice


15 October 2019
At the recent IOR best practice webinar for service engineers, Bill Barlow, OEM business unit director for Conex Bänninger, provided tips on how and where the manufacturer’s >B< MaxiPro press-fit range should be used for pipework joints, as well as the training available.
Conex Bänninger has been providing fittings for the ACR market for several decades. In the UK, we introduced our innovative >B< MaxiPro copper press fittings designed specifically for air conditioning and refrigeration applications in 2017.

Through this introduction we invited ACR engineers to join what we call ‘the press revolution’ by taking advantage of the benefits press joints have over traditional brazing.

The range is a natural development and extension of the press technology that was launched in the late 1990s and has been proven in the general plumbing and heating industry since then. 

>B< MaxiPro is designed for systems with a maximum operating pressure of up to 48 bar and an operating temperature range between -40°C to 121°C.

As with our >B< Press range for water applications, >B< MaxiPro fittings are secured with a three-point press. There is one press each side of the bead and a third compressing the O-ring. On >B< MaxiPro fittings of ½ inch and upwards an additional hook grips the tube to provide higher pressure tolerance.

One of its biggest advantages over brazing is that it is a flame-free solution. This means there’s no risk of fire on site and it eliminates the need for a hot works permit, which can be time-consuming both in applying for and then implementing.

There’s also no requirement for a nitrogen purge, which also saves time and cost.
In addition, the cost of installation per unit is lower than brazing because it is significantly quicker to complete a press joint.

Once initial preparation has been completed, it takes just five seconds to complete the joint using the appropriate press tool and jaws. Service engineers can be confident of a sound, secure, long-lasting joint every time.
Another benefit of press is that because the time taken to complete each joint is repeatable and therefore predictable, it means contractors can be confident of completing installations on time, which aids productivity and work scheduling.

From a practical point of view, it is also easier for the engineer when they are on a job as they don’t have to manhandle gas bottles or cylinders around, which makes site access easier and safer.

System testing
For tightness and strength testing, dry oxygen-free nitrogen should be used as this is inert. Do not use oxygen for pressure testing, as under pressure it reacts violently to hydrocarbons (oil and grease) and could cause a fire.
To ensure >B< MaxiPro fittings are tested safely, the pressure should be gradually increased to the desired test pressure as established by the installer.

If pipework is to be left pressurised for 24 hours or longer to check for leaks, the system pressure and the ambient temperature should be measured at the start and finish of the tightness test.

This is because a rise in ambient temperature can mask a leak if this is not taken in to account. There will be a pressure change of approximately 0.7 bar with a temperature change of 5°C.

At Conex Bänninger we’re committed to supporting the installer and helping ensure high quality installation standards. That’s why we have introduced a certified training programme for >B< MaxiPro.

Training is free and can be completed within an hour. It is offered on site, in conjunction with merchants and at our new purpose-equipped training centre. There is also an online training module. At the end of the course there’s a questionnaire, which the engineer has to pass.

The benefit of this is that if installed by a certified >B< MaxiPro ACR engineer, the one year guarantee on fittings is extended to five years. Terms and conditions apply.
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