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Pneumatic Timers: How They Work and How to Choose the Right Model

Timing is everything in automation. Whether you’re controlling the dwell time on a heat sealer, delaying the start of a conveyor, or ensuring a cylinder fully retracts before the next cycle begins, pneumatic timers provide reliable time delays without electronics. Because they operate using only compressed air, these devices are inherently safe, simple, and dependable.

How Do Pneumatic Timers Work?

A pneumatic timer creates a controlled delay by restricting airflow through an adjustable orifice or reservoir. When air enters the timer’s control port, it fills a chamber and slowly bleeds through a calibrated restriction. Only after the chamber reaches a specified pressure does the timer activate its output valve. By adjusting the size of the orifice or the volume of the chamber, you can precisely set the delay time, often from fractions of a second up to several minutes.

Because no electricity is involved, pneumatic timers are ideal for hazardous or remote locations. They continue to operate during power outages and are immune to electromagnetic interference. Their simple construction also means longer life and easier maintenance compared to electronic timers.

Example: EKCI’s PMTV Series

Ellis Kuhnke Controls offers several timer families, including the legacy PMT series and the newer PMTV series. The PMTV is a panel or subplatemounted pneumatic timer with an integrated 3way valve and timing range up to 180 seconds. This design simplifies installation and combines timing and directional control into a single compact unit. Such integrated solutions reduce the number of components in a control circuit and minimize potential leak points.

Selecting the Right Pneumatic Timer

When choosing a pneumatic timer, consider the following factors:

Timing range: Determine how long you need to delay the signal. Timers may be adjustable or fixed; choose a range that covers your maximum requirement with fine resolution for accurate control.
Function type: Decide whether you need an ondelay (signal delayed before activation) or offdelay (signal sustained for a set time after removal). Some timers provide both functions.
Valve configuration: Integrated 3way or 4way valves can directly operate cylinders or pilot other valves. For simple pilot signals, a bleedoff timer may suffice; for direct actuation, choose a timer with sufficient flow capacity.
Mounting style: Timers come in panelmount, subplatemount, or inline configurations. Select one that fits your space and simplifies maintenance. EKCI’s panelmounted PMTV series offers a clean front panel appearance and easy adjustment.
Environmental considerations: Ensure materials and seals withstand your operating environment (temperature, moisture, contamination). Stainless steel or anodized aluminum housings, along with fluorocarbon seals, enhance durability.

Applications for Pneumatic Timers

Pneumatic timers are used across industries.

Packaging machines: Delay sealing jaws or film clamps to ensure proper heat and pressure.
Material handling: Create dwell times between actuations of cylinders on conveyors and palletizers.
Safety interlocks: Provide delays to ensure guards are closed or operators have moved away before machinery cycles.
Process control: Introduce delays in blowoff, purge, or flushing operations in filtration and mixing systems.

Simplify Your Timing Challenges

Whether you need a simple ondelay for a small cylinder or a fully integrated timing valve for a complex assembly line, pneumatic timers deliver adjustable, maintenancefree delays without the complexity of electronics. Ellis Kuhnke Controls’ range of timers, including the versatile PMTV series with 3way functionality, helps engineers build reliable, selfcontained timing circuits. Contact EKCI to explore which pneumatic timer best fits your application and discover how air logic can keep your processes running on schedule.