P.E. Welding

The woods are alive with links.

On the surface they will be easy to fix. Any risk of freezing?

Drill down into thses and see what you find. Some reports on comparing the two.

http://www.google.com/search?hl=en&q=electrofusion+%2Bpolyethylene

http://www.google.com/search?hl=en&q=%22butt+welding%22+%2Belectrofusion+%2Bpolyethylene&btnG=Search

Do you mean Ultrasonic high-frequency-- and call it E.F?

And do you mean 'Heat to almost melting and Upset-Press' what you call "Butt Weld".

If so you need to read this and further>>>>:

The welding characteristics of a 67 kHz ultrasonic plastic welding system using fundamenta! and higher-resonance-frequency vibrations were studied and compared with those of the 27 kHz and 40 kHz systems. At high frequency, welding characteristics were improved due to the larger vibration loss of plastic materials. The 67 kHz welding tip vibrates at a maximum velocity of more than 2.3 m/s (peak-to-zero value) at a fundamental resonance frequency and there me several higher resonance frequencies up to 94 kHz whose vibration velocities are more than one-fourth that of the fundamental frequency. The welding characteristics of lapped 1.0-mm-thick polypropylene sheets were measured for the cases where the vibration system was driven using combined driving voltages of both fundamental and higher resonance frequencies. The welded area and weld strength increased when fundamental and higher resonance frequencies were driven simultaneously. The welding characteristics of the 67 kHz ultrasonic plastic welding system were improved significantly compared with those of 27 kHz and 40 kHz welding systems by driving fundamental and higher resonance frequencies simultaneously

Thanks for the info but I meant electrofusion for E.F. I did mention this at the end of the first paragraph. Butt welding is the only phrase I have ever known for the type of welding I was talking about. This is done by melting the two ends of the pipe and pressing together. Because polyethelene is a thermoplastic it welds together. This is done either by a computerised machine or with hydraulic clamps and charts telling you the pressure and time for welding.

I have been involved in the installation of literally hundreds of miles PE pipe for use in low pressure natural gas transmission and water transport. I definately recommend using butt welds and not electrofusion. The cost of the electrofuse collars is very high...also the automated machine to do it right is quite expensive in itself. The electrofuse joint usually takes 2-4 times longer than an butt weld and is not able to be visually checked for quality like the butt weld.

Both butt welding and E/F welding will give the same system lifetimes if carried out correctly. Generally butt fusion is used for long straight pipe runs and if Automatic Butt Fusion is used there is very little operator input, therefore the consistancy and quality of the weld is high. Electrofusion is generally used for repairs, "in trench" work, connections at the end of pipe runs (flanges etc). Electrofusion relies more on operator skill as the joint preperation is a manual process, scraping, alignment, etc.

If you are using 6 or 12 metre sticks, suggest you stick with butt fusion, if you are using coils the E/F joints are easier and the equipment requirement is smaller.

Sorry forgot to register on my last response, if you have any other questions about EF or BF let me know.