Solve Your Flow Control Problems With Flow Calibrated Orifices


Flow calibrated orifices have a flow diameter that can be used to calculate the flow rate of any gas or mixture of gases when the absolute inlet/outlet pressures and absolute temperature are known. The flow diametre gives accurate results regardless of the actual shape of the hole.

Holes flow calibrated by the Lenox Laser Corporation are now being used by thousands of customers and have proven to be more accurate and less costly than most flow controlling devices.

Shown below are some of our standard parts used for flow control. Custom sizes and shapes are readily available. Holes are drilled in a variety of materials, such as, plastic, glass, most metals and other materials.

Let Lenox Laser help you solve your flow control problems by calling 410-592-3106 or by visiting

Standard Drilled Gasket

Standard Gland

1/8 NPT x 3/16 Barb

Nipple Fitting

1/4-28 TPI Set Screw

1/8 Stainless Steel Tubing

Free Online Critical Flow Orifice Calculator


Lenox Laser has been a pioneer and a leader in the critical flow orifice field for over 20 years. Customers have had orifices custom sized, drilled, and calibrated for them in various flow components in order to meet complicated and critical needs. We are able to eliminate the need for expensive and complicated mass flow controllers with our easy to use, inline, consistent, and cost-effective orifice technologies. A Lenox Laser calibrated orifice will produce consistent and repeatable flow rates of gas and liquids time and time again.

Lenox Laser has also created easy to use Orifice Sizing Calculator which has aided thousands of customers determine their orifice size for their flow control application. The calculator uses our flow control mathematics formulas which can be found in detail here. Our free online calculator can determine an orifice size using the following input values:

Inlet Pressure – PSIA, PSIG, Inches Mercury Absolute, Inches Water Absolute, Barr, Torr, Atmosphere, Kilopascals

Outlet Pressure – PSIA, PSIG, Inches Mercury Absolute, Inches Water Absolute, Barr, Torr, Atmosphere, Kilopascals

Gas Type – Air, Acetylene, Ammonia, Argon, Carbon Dioxide, Carbon Monoxide, Ethylene, Helium, Hexahydrochloride, Hydrochloric Acid, Hydrogen, Methane, Methyl Chloride, Nitrogen, Nitric Oxide, Nitrous Oxide, Oxygen, Sulfur Dioxide

Temperature – Fahrenheit, Celsius, Kelvin

Flow Rate – std cubic cm/sec, std cubic cm/min, std cubic cm/hr, std cubic ft/sec, std cubic ft/min, std cubic ft/hr, std gal/sec, std gal/min, std gal/hr, std liters/sec, std liters/min, std liters/hr, std pounds/sec, std pounds/min, std pounds/hr, std grams/sec, std grams/min, std grams/hr

Hole Units – Microns, Inches

The calculator will then display the appropriate hole size which Lenox Laser will be able to drill, calibrate, and certify your flow rate for your specific application in almsot any type of disc, VCR Gasket, Gland, Conflat, Barb/Luer, Nipple, Set/Hex Screws, and High Pressure or High Temperature Tubing. Custom parts and materials are also available for drilling with a setup fee.

Meet Thomas Young

Thomas Young was an English polymath (a person with encyclopedic or varied knowledge or learning) who contributed to the scientific understanding of vision, light, solid mechanics, energy, physiology and Egyptology.. So great was his knowledge that he was called “Phenomena Young” by his fellow students at Cambridge.
Young was born in 1773, the eldest of 10 children. By the age of fourteen, he had learned Greek and Latin and was acquainted with French, Italian, Hebrew, Chaldean, Syriac, Samaritan, Arabic, Persian, Turkish and Amharic, a Semitic language spoken in North Central Ethiopia.

In 1792, Young began to study medicine in London. He later moved to Gottingen, where he obtained his doctorate in physics in 1796. A year later, in 1797, Young entered Emmanuel College at Cambridge. By 1799, Young had established himself as a physician in London where he published many of his first academic articles anonymously to protect his reputation at a physician. It is to be noted that while studying medicine in London, he explained the mode by which the eye accommodates itself to vision at different distances as depending on change of the curvature of the crystalline lens. This was to prove valuable to him being the first to describe astigmatism.

In 1801, Thomas Young was appointed professor of natural philosophy (mainly physics) at the Royal Institution in Cambridge. His initial interest in light and vision carried over to this new academic endeavor. Here, Young presented the hypothesis, later developed by Hermann von Helmholtz, that color perception depends upon the presence in the retina of three kinds of nerve fibers which respond respectively to red, green and violet light. This theory was experimentally proven in 1959, one hundred fifty eight years later!

While at Cambridge, Young performed his now famous double slit experiment where he passed a beam of light through two parallel slits in an opaque screen, forming a pattern of alternating light and dark bands on a white surface beyond which established that light was a transverse wave motion whose wavelength determined color (see wave interference). His findings were strongly opposed by contemporary scientists who believed that Newton, who had proposed that light was corpuscular in nature, would not possibly be wrong. However, Young’s work was soon confirmed by the French scientists, Fresnel and Arago.

In 1804, Young’s essay, “Cohesion of Fluids”, founded the theory of capillary phenomena on the principle of surface tension. He also observed the constancy of the angle of contact of a liquid surface with a solid, and showed how from these two principles to deduce the phenomena of capillary action (see Young-Laplace Equation and the Young-Dupre Equation). He went on to describe the characterization of elasticity that came to be known as Young’s Modulus.

After holding positions at St. George’s Hospital and on various scientific boards and committees, Thomas Young died in 1829 after a relatively short but distinguished career. His contemporary, Sir John Herschel, called him a “truly original genius”. Young being the first to define the term “energy” in the modern sense, was praised by Albert Einstein in his 1931 forward to an edition of Newton’s Opticks. Other admirers include physicist Lord Rayleigh and Nobel laureate Philip Anderson.

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