Guidelines for construction of low‐pressure gas manifolds

Expressions are obtained for the outflow pattern from the orifices of a gas manifold in the molecular flow regime. The example considered in detail is a section of tubing with identical holes equally spaced along the tube. The manifold is characterized by k, the number of holes, and n, a conductance ratio. Example of outflow patterns for various values of n and k are given. The quantity kn^−1/2 emerges as a figure of merit for uniform discharge. A simple experiment supports the usefulness of the model used.