Find Precision Flow Orifice

We stock Silicon orifices with diameters as low as 0.001"

Sapphire orifices with diameters from 0.003" to .033"

and SS orifices with diameters 0.030"- 0.080"

No matter what flow specification, there is an orifice within a few percent of the requirement.

Universal Microsystems
Universal Microsystems
3300 Victor Court
Santa Clara, CA 95054
  • We use a three digit ID code to specify the required orifice
  • If you know the required diameter, find the ID in the table below
  • If you know the nitrogen flow at inlet pressure Pi =20 psig, also find it in the table below
  • If Pi differs from 20 psig, calculate it by multiplying the required flow by 34.7/(Pi+14.7)
  • If the gas is not nitrogen, divide the required flow by K in the table below

  • Stainless Steel Orifices use the ID of Fxx where xx is the diameter in .001"
    F05, and F30-F-80 available
    N2 @ 20 psig = 13.4(xx)2

  • If outlet pressure is > half inlet pressure use
  • Table of stock Silicon and Sapphire Orifices
    vs orifice diameter and flow of nitrogen at 20 psig
    Nxx orifices have beveled inlet shape (higher flow) compared to Rxx orifices with flat inlet shape
    Silicon Orifices require VS or KS in part number ID, sapphire and SS require FS
    Caution, silicon orifices should not be used in exhaust streams from chambers with flourinated plasmas

    Part numbering system: