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:
- 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.
- 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.