I am trying to parameterize the surface of a 3D helix tube like below.

As known, a parametric curve only requires one parameter $t$
$x=R\sin(t)$, $y=R\cos(t)$, $z=p t$,
where $R$ is the radius, and $p$ represents the pitch.
However for a surface, I think I need at least two parameters $t_1$ and $t_2$ to represent the 3D closed surface of a 3D helix tube.
Here, I need $x$, $y$, and $z$ in the parametric equations to be "decoupled". i.e., I am expecting something like
$x=f_1(t_1, t_2)$, $y=f_2(t_1, t_2)$, and $z=f_3(t_1, t_2)$.
What are the expressions?