Pneumatic Timer Technology

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

Reservoir fill pneumatic timers are the most basic 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 pressure build-up overcomes the valve spring tension and switches.

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

In most cases, timing ranges for reservoir fill and spring diaphragm designs only allow short timing intervals due to limited air reservoir capacity. The setting dials have no precise time setting incrementation on the dial; for example, the dial only shows letters, lines or an increasing line scale, making it challenging to set or adjust accurately. In applications where vibration may occur, 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 with sweeping timing hands, a single incremented figure wheel, or a digital display up to 5 digits showing minutes or seconds.

Accurate dial incrementation assists the quick and successful set-up; so unlike reservoir fill and spring diaphragm designs, the operator can instantly and easily view a process value partway 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 applications; we are always ready to help you.