McElroy Discussion Forums

Is there a Butt fuse bead size gauge available for purchase?

Sorry to say that there it not such of a device. There are too many variables to bring quality all the way back to bead size. Just to touch on some of the main reasons that this prove to be a challenge.
- Ambient temptaure.
- Wind exposure
- Material temptaure before bead-up.
- Actual heater plate surface temptaure.
- Welding parameters.
- Material quality
- Type of material, pipe or fittings
Due to the above items that fall outside the control of the people put in charge of making a proper fusion joint there will always be a variance of bead size. My recommendations would to be to pay close attention to bead shape around the whole joint. You would need to check that the beads are symmetrical all the way around. You find that if you only look at the size then you are not capturing all that could be there. Bead size can easily be manipulated in ways that could be detrimental to weld quality. The best quality assurance you can provide is proper training to the fusion crews as well as testing.

I know that you are asking this question of McElroy and I too am looking forward to their response. My opinions and recommendations are that of a distributor and could vary from others. I urge others to use this so that we can bring this to light and address it.

Dave, I think that was a great response!

I will add that the ASTM F2620 standard has been recently changed to require minimum soak times, maximum heater removal times, and minimum cool times based on pipe wall thickness to help reduce some of the variables, (Some other changes were made as well,) but the key that has already been stated here is proper training and operation of the fusion machine, backed up by a DataLogger® and sample testing with either the McSnapper™ or In Field™ Tensile Tester. If all fusion parameters are correct, the bead size itself is not a critical dimension and does vary.

John

if you email me at r.keys@qwestoffice.net i may have what you are looking for.