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.