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Bermad Model 430 - Pressure Relief/Sustaining Valve

The BERMAD Model IR-430 Pressure Relief/Sustaining Valve is a hydraulically operated, diaphragm actuated control valve that can fulfil either of two separate functions. When installed in-line, it sustains minimum preset upstream (back) pressure regardless of fluctuating flow or varying downstream pressure. When installed as a relief or circulation valve, it relieves line pressure in excess of preset.


Features and Benefits

  • Line Pressure Driven Pressure Relief/Sustaining Valve
    - Controls system fill-up
    - Sustains upstream line pressure
    - Relieves excessive pressure protecting pump and system
    - Prioritizes pressure zones
  • Advanced Globe Hydro-Efficient Design
    - Unobstructed flow path
    - Single moving part
    - High flow capacity
  • Fully Supported & Balanced Diaphragm
    - Requires low opening and actuation pressure
    - Excellent low flow regulation performance
    - Progressively restrains valve closing
    - Prevents diaphragm distortion
  • User Friendly Design
    - Easy pressure setting
    - Simple in-line inspection and service
Pressure Sustaining Valve
[1] BERMAD Model IR-430 protects pump from overload and cavitation, prevents main line emptying, and controls system fill-up.
[2] BERMAD Check Valve Model 70NCirculation / Relief Valve
[1] BERMAD Model IR-430 safeguards pump minimum flow and relieves excessive line pressure.
[2] BERMAD Active Check Valve Model 740Q

Typical Applications

  • Downhill Supply Lines Emptying Prevention
  • Pressure Zone Prioritizing
  • Line Fill-Up Control
  • Pump Overload and Cavitation Protection
  • Pump Minimum Flow Safeguard
  • Excessive Line Pressure Protection

Technical Specifications

Dimensions and Weights

Technical Data

Patterns and Sizes: Globe: 3-16”; DN80-400 Angle: 3-4”; DN80-100

End Connections:

Pressure Ratings: 16 bar; 232 psi

Operating Pressure Range: 0.5-16 bar; 7-232 psi

For lower pressure requirements, consult with us

Setting Range: 1.5-16 bar; 22-232 psi

Setting ranges vary according to specific pilot spring. Please consult with us.


Body and Cover: Polyester Coated Cast or (10”; DN250 and larger) Ductile Iron

Spring: Stainless Steel

Diaphragm: Nylon fabric Reinforced NR with rugged insert Bolts, Studs and Nuts: Zinc-Cobalt plated Steel

Control Accessories: Brass

Tubing and Fittings: Reinforced Plastic and Brass

Flow Chart


The Needle Valve [1] continuously allows line pressure into the Control Chamber [2]. The Pressure Sustaining Pilot [3] senses Upstream Pressure [P1], and throttles when it drops below setting*. Pressure then accumulates in the control chamber causing the Valve to throttle closed maintaining [P1] at pilot setting, and eventually closing drip-tight. The pilot releases accumulated pressure when [P1] rises above setting, thereby causing the Valve to modulate open.

* Sustaining (In-Line) Valve Pilot should be set to minimum system pressure allowed.

Relief (Circulation) Valve Pilot should be set slightly above system working pressure.

How to Order

Please specify the requested valve in the following sequence: (for more options, please contact us.)

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Engineering Data*
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Product code

Bermad Model 430 - Pressure Relief/Sustaining Valve

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