Slide background

Precision Orifices for Flow Control

Precision orifices, also known as flow restrictors, regulate flow in pneumatic or fluid systems. These regulatory devices are available in many different sizes. The size of the orifice defines how quickly water or gas can pass through the system, and the resulting flow rate remains consistent with a high degree of accuracy. Airtrol Inc. supplies a full lineup of plastic precision orifices, molded with tight tolerances for maximal performance at low cost.

Precision Orifice Uses

Precision Orifice Uses

Precision Orifices for Flow Control

Precision orifices are designed with simplicity and versatility in mind. When sized correctly, plastic flow restrictors can serve a variety of functions in a fluid or gas system. The most common application is to regulate the flow of fluid or gas within any number of industrial systems.

The orifice diameter with the characteristics of the flowing material defines a flow rate for the system, which remains constant within a small margin of error. In this way, precision orifices form an elegant solution for maintaining flow rate. Other common uses include the following:

  • Cylinders and actuators must typically spin at a set rate. Precision orifices can easily maintain this rate as pneumatic components operate.
  • In pneumatic systems, precision orifices throttle pressure by restricting gas flow to a specified level.
  • Similarly, precision orifices act as snubbers—that is, they prevent dangerous spikes in pressure by distributing pressure changes over a set distance.
  • Finally, miniature precision orifices, in particular, are sometimes used as a source of ultrasonic sound, which can be generated when air moves through a small opening.

Why “Precision” Is Important

Precision orifices are so named because they passively maintain an exact flow rate, enabling the many applications listed above. Precision, in this sense, is not just a benefit but a critical feature that enables proper system functioning. These components enable fine-grained control of parameters such as:

  • Flow Rate: When using a precision orifice, flow rate is predictable, accurate, and consistent. Before purchasing an orifice, it’s important to calculate the diameter and shape necessary to achieve the desired flow rate. However, once installed, little additional maintenance is necessary to keep the system flowing exactly as it should.
  • Flow Ratios: Along similar lines, precision orifices can also regulate flow of multiple materials to achieve a desired ratio. To use orifices in this way, each liquid or gas should be routed through its own flow regulator such that, over a set period of time, the ratio of all outputs matches some predetermined value. While this requires some calculation upfront, the method allows for a self-sustaining method of flow rate and ratio regulation.
  • Timing: Circuits demand precise timing to function properly. Precision orifices ensure that flow continues as expected to prevent malfunction.
  • Repeatability: In any industrial process, repeatability is a critical metric, allowing for confidence in a system’s integrity. Imprecise components compromise this reliability.
  • Consistency: Inconsistent flow is not just a minor annoyance. Over time, irregularities or incompatible regulatory components can damage piping, leading to erosion or surface buildup. Application-specific, tightly controlled components are therefore necessary to protect the system in both the short and long term.

Applications for Precision Orifices/Flow Restrictors

As detailed, precision orifices can fulfill many functions, including flow regulation and pressure throttling. However, these capabilities are especially useful in certain industries:

  • Medical and Dental: Many medical devices rely on tightly controlled gas or liquid flow, including incubators, respiration equipment, and pneumatic beds and chairs.
  • Laboratory and Analytical Instrumentation: Labs and testing facilities cannot guarantee accurate results without reliable methods of obtaining and analyzing samples. Flow restrictors can regulate performance at either stage of analysis in all manner of lab testing processes.
  • Aerospace: Actuators and pneumatic controls are used throughout the aerospace industry for such diverse functions as engaging the landing gear and controlling cargo doors. Precision orifices are a cost-effective but reliable method of regulating these processes.
  • HVAC: Precision orifices provide a simple means of maintaining appropriate flow in heating and cooling systems.
  • Process Control and Automation: Even the most complex orifice designs are ultimately passive, maintaining system performance with little need for operator intervention. These properties make flow restrictors ideal for use in process control or automation processes, where they allow for hands-off, streamlined operations at a low price.

Precision Orifices for Flow Control


Precision molded orifices feature accuracy comparable to jewel orifices at a fraction of the cost.


A precision adjustable flow control used in pneumatic and fluidic systems.


Barbed fittings fit Airtrol R-900 and V-900 series regulators, and all Airtrol switches.

About Airtrol’s Orifices

Airtrol is a leading provider of plain and barbed precision orifices, as well as accompanying filters and valves. All Airtrol flow restrictors are composed of durable, FDA-approved polycarbonate, which mimics the performance of more expensive materials at a drastically lower price point. Our standard precision orifice offerings include the following varieties:

  • Plain Orifices: Color-coded and molded with tight tolerances, Airtrol plain orifices are cost-effective but never cheap. These restrictors are compatible with 1/16” ID tubing and available with a range of orifice diameters.
  • Orifices With Barbs: Barbed orifices incorporate an integral steel mesh filter to prevent clogs at high operating pressure. Like our plain restrictors, all barbed orifices are fully color-coded and marked for easy installation.

Other performance components and accessories are available, including:

  • In-line Filters: Airtrol’s advanced in-line filters are composed of 304 stainless steel, durable Dutch weave screens. Available in 5, 40, and 80-micron configurations, these disposable in-line filters are the easiest way to safeguard against clogs.
  • Needle Valves: Needle valves improve on the functionality of flow restrictors by allowing adjustable flow control. Our needle valves are constructed from sturdy stainless steel and are suitable for any application that calls for variable control of metering, speed, or sequencing.
  • Barbed Fittings With Orifice Inserts: Although designed to fit into Airtrol 900 series regulators, flush mounts, and panel mount switches, this line of barbed fittings use a 10-32 male thread compatible with most common pneumatic equipment.

Our Home Office in New Berlin

Airtrol’s Advanced Pneumatic Solutions

Airtrol has been family owned and operated for over 40 years, and in that time, we’ve built a reputation founded on reliability and quality. Our specialty is lightweight, performance pneumatic components for light to medium operations, including cost-effective precision orifices, filters, and valves.

To learn more about our existing product lines, get in touch with us today, or contact a product engineer to discuss the possibility of a custom design.

Ready to Start? Request a Quote Today