L404 and L604 Pressuretrol
line voltage pressure controllers that provide oper-
ating control, automatic limit protection, or manual
reset limit protection for pressure systems of up to
300 psi (21.1 kg/cm
or 2068 kpa).
Can be used with steam, air, non-combustible gases,
or fluids non-corrosive to the pressure sensing ele-
Stainless steel diaphragm (except 300 psi [21.1 kg/
(2068 kPa)] models) also allows use with am-
monia, oxygen, distilled water, and similar media.
L404B is recommended for supervision of atomiz-
ing medium pressure in oil burner systems.
Models are available with spst, spdt, or dpst switch-
ing and in variety of operating ranges.
Dustproof, trouble-free mercury switches (all mod-
els except L404F, which has snap-acting switch).
Automatic reset models have adjustable, subtractive
differential (except L604M).
Trip-free mechanism on manual reset models as-
sures that limit function of controller cannot be
defeated by jamming reset lever.
L. Z. • Rev. 3-95 • ©Honeywell Inc. 1995
Screw adjustments made on top of case.
Scaleplates marked in English (psi) and Metric
L404F models available with European enclosure,
British Standard Pipe Threads, ground screw, and
scaleplates marked in kg/cm
Clear plastic cover on case to observe pressure set-
tings and switch action.
Leveling indicator visible through cover.
Hexagonal fitting with 1/4-18 NPT internal threads
for direct mounting to 14026 Steam Trap (siphon
Surface mount is available using screws through
holes (knockouts) in case backing.
and either psi or kPa.