No, there's no need to blanche any more, Bugs. Use this method - dry freezing. It's easy,foolproof and works every time.
Wash and thoroughly dry the runner beans.
Cut them as you normally would for cooking.
Spread them out on a clean tea towel.
Fold in the sides and roll them up.
Put in the freezer for 12 hours.
Take them out of the freezer; move them around with your fingers to ensure they are separate.
Roll them up again and put them in the freezer for 48 hours.
Take them out and put them in the portion sizes you would normally eat and put these into either a freezer box with freezer paper between the portions. Alternatively put each portion into a plastic freezer bag.
Return them to the freezer.
When you are preparing them for cooking, bring slightly salted water to the boil and put the frozen beans straight into the water -don't allow them to thaw. Simmer for about 5 mins.