Radium Engineering Adjustable Pressure Switch | Universal (20-0236)

A second fuel pump running full-time is wasted heat and noise; one that wakes up on boost is a system.

Staged pumps need a trigger that knows when the engine actually needs them. The Radium Engineering Adjustable Pressure Switch watches positive boost pressure and closes at a set point you dial in anywhere from 3 to 15 psi, firing the relay for your staged pump exactly when demand arrives. It is a normally open switch in a stainless housing, and because it is a general-purpose trigger, it can switch any low-current device, not just fuel pumps. Set it, plumb it to boost, and let the fuel system stage itself.

What You'll Feel

• A quieter, cooler fuel system at cruise, with the staged pump asleep until boost calls it
• Longer pump life, since the second pump only runs when it is actually working
• Full flow arriving automatically at your chosen boost threshold, no driver input
• An adjustable set point that moves with the build as boost targets change

Features

• Normally open (N.O.) pressure switch triggered by positive boost pressure
• Adjustable set point from 3 to 15 psi to match the application
• Stainless steel construction
• Designed to trigger a relay; switches any device drawing less than 0.5 amp on the trigger circuit
• General-purpose: staged fuel pumps, warning devices, or other boost-referenced switching

The Details

The wiring architecture matters here, and Radium is specific about it: the switch is a signal device, not a power device. It closes the low-current trigger circuit of a relay, and the relay carries the pump's actual load, which is why the 0.5 amp trigger limit exists and why pairing this switch with a Radium DIY fuel pump wiring kit per staged pump is the clean install. Plumb the switch's pressure reference to a manifold boost source, set the adjustment to your desired staging threshold, and the sequence takes care of itself: below the set point the normally open contacts stay open and the staged pump rests, above it they close, the relay latches, and the pump joins the party. This is the standard method for staging surge tank and MPFST pumps so a triple-pump system idles on one pump and delivers everything under load. Review Radium's installation instructions for the wiring diagram before final hookup.

Kit Includes

• 1x Adjustable pressure switch, 3-15 psi, normally open

Applications

• Universal: staged fuel pump triggering on boosted engines
• Radium MPFST, FST, and multi-pump hanger systems with staged pumps
• Any boost-referenced relay trigger duty under 0.5 amp