Pneumatic Timer Technology

Pneumatic timers use different technologies to achieve a timing function; each manufacturer adopts a particular technology within its timer range, these are reservoir fill, spring diaphragm and geared designs, each technology type has benefits and limitations.

Reservoir fill pneumatic timers are the most straightforward design, typically constructed using a one-way flow restrictor, a reservoir, and a pilot spring return valve, all combined into one housing. A pneumatic flow restrictor allows air to fill the reservoir volume at a preset rate; the gradual build-up of pressure overcomes the valve spring tension and the valve switches.

Spring diaphragm timers use a separate atmospheric volume that is spring controlled, there are a few design types within this technology group, but primarily, they function the same. The fundamental point is that atmospheric pressure and line pressure are independent of each other, so there are no adverse timing fluctuations, making these particular timers reliable when line pressures increase or decrease.

Timing ranges for reservoir fill and spring diaphragm designs, in most cases, only allow short timing intervals due to limited air reservoir capacity. The setting dials have no exact time setting incrementation on the dial; for example, the setting dial only shows letters, lines or an increasing line scale, making them challenging to set or adjust accurately. Applications where vibration may occur, both reservoir fill and spring diaphragm timers are resilient due to construction with few moving parts.

Geared timers come equipped with a traditional analogue clock face and timing, an incremented figure wheel, or a digital display with 3 or 5 digits minutes or seconds timing.

Accurate dial incrementation assists the quick and successful set-up of geared design timers; unlike reservoir fill and spring diaphragm designs, the operator can instantly and easily view a process value part way through timing. Timing sequences are unhindered by pressure fluctuations making repeat accuracy reliable and consistent every time.

Impulse Automation has years of experience offering pneumatic timers and counters across all sectors of industrial automation; our knowledge is unmatched; we are the experts. Please call us for further information regarding your specific applications; we are always ready to help you.