This may help, you maybe able to butcher the driving curves to create a similar model: Progressive Spiral with Rhino XX feasible?
On second thoughts… You could probably do this by creating a cone that is 1/2 the circumference of the ring you want. Follow the tips above and then mirror and rotate it (maybe you’ll have to split the end at the widest point at a quadrant of the final twist of the helix.)
You could then flow the shape around the curve and then pipe it rather than piping it then flowing around the curve. I think you’ll be able to spilt and blend curves to remove any kinks or non tangent joined curves.
Andy