Pressurematic™ Constant Pressure Relief Valve


This proprietary design is so effective at keeping the pressure constant it is hard to believe without seeing it for yourself. It can hold the set pressure to within 1psi over it entire working range.


The inlet pressure will only increase after the flow rate has exceeded the Pressurematic's operating limit. For potentially higher flow rates, several Pressurematics can be used in parallel.


  • Adjustable pressure setting is tamper resistant
  • Inlet pressure within +/- 1 psi of factory set pressure
  • Designed for 20 year maintenance free life cycle


  • Flow: 0.1 to 24 GPM (0.3 to 90.84 l/min.)
  • Pressure: 10 to 150 psi (0.7 to 17 bar)
  • Temperature: up to 150° F (66°C)
  • Custom Sizing Available


  • 1 3/4" H x 2 3/4" L x 1 3/4" W (4.4 cm H x 7.0 cm L x 4.4 cm W)
  • Male inlet/outlet: 12 & 16 size SAE 37° JIC
  • Wet Materials: 12L14 steel, zinc-plated; aluminum alloy, Viton O-ring

What It Does

Unlike other relief valves, the Pressurematic™ is specially designed to maintain constant pressure at its inlet over its entire operating flow range. This makes the Pressurematic™ ideal in positive displacement pump applications where line flow may vary with time, but constant fluid pressure is critical.

EXAMPLE: an industrial fluid bottle filling line would use a Pressurematic relief valve to regulate the fluid pressure before the bottle filling mechanism. Pressure in this line would be held constant while flow would be allowed to vary depending on how many filling mechanisms were in use at any given moment. Since the Pressurematic closely maintains line pressure, a precise and repeatable amount of fluid could be dispensed every time.

4500_in_use (42K)

The Pressurematic™ is not a normal pressure regulator. Rather than reacting to fluid pressure at its output, as a pressure regulator would, the Pressurematic™ reacts to pressure at its input. This is an important characteristic for maintaining line pressure in positive displacement pump systems. This is because the pressurematic will divert excess flow back to the reservoir, preventing pump stall, a line burst, or worse. In the bottle filling example, say all of the filling mechanisms are closed. In this situation, the Pressurematic™ would allow 100% of the flow to pass through to the reservoir. Pressure and flow would be constant at the pump outlet, regardless of the status of the filling mechanisms.

How It Works

The Pressurematic™ is unlike any other relief valve on the market today. Most relief valves are configured similarly to the following diagram:

typical (24K)

In this configuration, the valve is designed to open when the inlet pressure on the piston is great enough to compress the spring. Once open, however, the valve has a very poor ability to regulate pressure. Since the fluid flow meets the piston head-on with a large axial velocity component, The effective area of the valve opening becomes a function of flowrate and pressure. This type of valve is usually used as a safety valve and is not suitable for pressure regulation.

VARNA's Pressurematic™ uses the following configuration:

4500_diagram (19K)

The Pressurematic™ Constant Pressure Relief Valve uses six radially oriented chambers to dissipate fluid kinetic energy. This way, the spring compression is a function only of inlet pressure and not of flowrate. This characteristic makes the Pressurematic™ ideally suited for line pressure regulation. Additionally, the Pressurematic integrates damping regions into the valve, offering even greater levels of pressure control.

To inquire about the Pressurematic™ Click Here, or Call 888-676-7770.

Efficiency is the art of getting the most useful work done with the least energy input. Many commodity pumps are designed to do everything poorly. Varna pumps are not right for every application but they can often get 'the job done' with half the motor of a lesser pump, saving the owner money up front and every day the pumps runs. Now that's efficiency!

Customer Feedback "It has now been about a year since we switched to Varna pumps, and now I receive nothing but compliments about how quiet our vehicles are,
Chief Mechanical Engineer Alan Arkus of AMP Electric Vehicles

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888.676.7770 | 2018