QBS High Pressure Valve

QBS High Pressure Valve

Often, control applications will demand precise pressure regulation of air or gases at high pressures with low flows. Proportion-Air developed the QBS high pressure valve for this reason.

  • Full vacuum to 500 PSI (34.47 Bar)
  • Wide range of analog and digital command signal options
  • Stainless steel, aluminum or nickel-plated brass bodies available

This device uses two high pressure solenoid valves and a stainless steel sensor to control the pressure with an internal control board at an output accuracy of ±0.5%. The QBS is perfect for low flow (<1 SCFM) applications under static/deadheaded conditions. If higher flow rates are required, we can often mount the QB2S on a volume booster to meet those needs.

Accuracy ±
Repeatability ±
Max P2 (PSI)
Max P2 (PSI)
  • Technical Specs
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Technical Specs

Pressure RangeVacuum thru 500 PSI (34.7 Bar)
Accuracy±0.5% F.S.
Repeatability±0.05% F.S.
Max Flow1.2 SCFM (34 LPM)
Port Size1/8″ NPT (BSPP Available)
DurabilityImmune to shock & vibration (up to 20 Gs)
Operating Temps32-158°F (0-70°C)
Filtration40 Micron


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QB1S | Internal Sense

The QB1S is a complete closed-loop high pressure control device consisting of valves, manifold, housing and electronic controls. The QBS series uses an internal stainless steel sensor to accurately control pressures from full vacuum up to 500 PSI. The user supplies a command signal and the internal transducer constantly compares this command signal with actual downstream pressure. Then the control board will open the inlet valve to allow more pressure, open the exhaust valve to relieve pressure or close both and hold pressure when the two signals agree. The QB1S is designed to use in static and deadheaded applications requiring low flow.

QB2S | External Sense

The QB2S is similar to the QB1S but uses a double-loop control scheme. In addition to the internal pressure transducer, the QB2S receives an electrical signal from an external sensing device (pressure transducer, load cell, etc.). This primary feedback signal is compared against the command signal input. This comparison is then summed with the internal pressure transducer signal. The gain of the circuit is such that priority is given to the external feedback signal. A difference between the command signal and the feedback signal causes one of the solenoid valves to be activated. The QB2S can be paired with a high flow/high pressure volume booster to control high pressure to a process requiring high flow as well.