What Is A Lockup-Type Regulator & Why Do I Need One In High Pressure Gas Applications?

What Is A Lockup-Type Regulator & Why Do I Need One In High Pressure Gas Applications?

What Is a Lockup-Type Regulator?

A lockup regulator is a pressure-reducing device that completely shuts off gas flow when the downstream system isn’t calling for it. Once the set outlet pressure is reached, the regulator seals tightly. No gas continues to flow unless there’s active demand.

This is in contrast to a non-lockup regulator, which might still allow some gas to "creep" through even when demand is zero. That creeping flow can raise pressure in downstream piping or inside sensitive gas valves.


Why It Matters in High-Pressure Systems

Many commercial gas systems use two-stage regulation. For example, the main gas supply might come in at a high pressure (e.g., 2 psi or higher), but the appliance may only require low pressure (e.g., 4–10.5 inches water column).

Without a lockup regulator, pressure can build up downstream of the regulator during idle periods. This can:

  • Cause false high-pressure trips
  • Damage internal gas valves
  • Lead to ignition or combustion issues
  • Create unsafe operating conditions

The lockup feature is what prevents these issues. It ensures the burner only sees the correct pressure when it needs it, and zero flow when it doesn’t.


Why It Needs to Be 10 Feet Away

There are two key reasons the lockup regulator must be located a minimum of 10 feet from the unit:

  1. Pressure Stabilization: The 10 feet of piping between the regulator and the appliance acts as a pressure dampening zone. When the appliance calls for gas and opens its internal valve, the sudden drop in downstream pressure can cause a momentary surge or oscillation from the regulator. The length of pipe adds volume and resistance, which helps buffer these pressure fluctuations and gives the gas time to equalize more gradually. This buffering is critical for modulating appliances, which vary their gas demand frequently and need a stable, consistent supply to maintain combustion quality and prevent nuisance lockouts or flame instability.
  2. Noise and Vibration Isolation: Regulators adjusting flow under high pressure can produce mechanical vibration, pulsation, or even audible humming. These disturbances can travel through rigid piping and interfere with the appliance’s gas train, burner, or pressure sensors. A 10-foot distance provides a physical separation that allows mechanical energy to dissipate before reaching sensitive components. This not only protects internal parts from vibration-related wear but also helps prevent false readings or unexpected burner behavior caused by harmonics or gas pressure instability.

Summary

A lockup-type regulator ensures your high-pressure gas system can safely and reliably step down pressure before reaching the appliance. By placing it at least 10 feet away, you’re giving the system the space and stability it needs to operate correctly. Without it, you’re inviting operational headaches—or worse, dangerous conditions.

Most,  if not all,  modulating/condensing boiler manufacturers require a lockup-type gas regulator for all of the reasons and examples given above. 

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