PRESSURE SWITCH H100-361 United Electric, USA

Overview

The United Electric H100-361 pressure switch is a heavy-duty industrial unit engineered for reliable set point control in demanding process environments. With an adjustable set point range of 20 to 300 psi and a dead band of 1 to 7 psi, it provides repeatable switching for pressure alarm, shutdown, and control duties in industrial plants.

Manufactured in the USA by United Electric Controls, the H100 series is a proven workhorse for pressure protection across oil and gas, chemical, and utility applications. The 316L stainless steel wetted parts and Type 4X enclosure make the H100-361 suitable for corrosive and outdoor service.

Engineering & Design

The switch mechanism uses a diaphragm piston sensing element that translates process pressure into a precise snap-action electrical switch, eliminating drift and providing consistent dead band performance. The die-cast aluminium enclosure is epoxy powder coated, gasketed, and fitted with captive cover screws for Type 4X weatherproof and corrosion-resistant protection.

Pressure connection is 1/4 inch NPT female, and the electrical rating of 15A at 125/250/480 VAC resistive allows direct switching of control circuits and motor starter coils. The ambient temperature range of -40°C to 71°C permits installation in outdoor and unheated industrial locations across the Gulf region.

Key Features

• Adjustable set point range 20 to 300 psi
• Dead band 1 to 7 psi for stable operation
• Max over range pressure 300 psi, proof pressure 800 psi
• 316L stainless steel wetted parts
• 1/4 inch NPT female pressure connection
• Type 4X certified die-cast aluminium enclosure
• Epoxy powder coated, gasketed with captive cover screws
• Electrical rating 15A @ 125/250/480 VAC resistive
• Ambient temperature -40°C to 71°C
• Manufactured in the USA by United Electric Controls

Applications

• Pressure alarm and shutdown on compressors and pumps
• Lubrication and seal oil pressure monitoring
• Process line pressure protection
• Hydraulic system pressure control
• Utility and water system pressure switching
• General industrial pressure protection

Specifications

Pressure switches remain the workhorse of industrial alarm and shutdown circuits because they are simple, reliable, and independent of the control system. The United Electric H100-361 pressure switch follows this principle with a robust mechanical design that provides a direct, hard-wired response to pressure excursions without dependence on power supplies or electronics.

For pressure protection duties, the United Electric H100-361 pressure switch is a proven choice, and Seven Star LLC supplies the United Electric H100-361 pressure switch with verified documentation for your instrument records.

For the high pressure lines above the standard range, the H100-361 switch is specified with the higher range spring of the series, and the set point is checked against the process relief pressure at the site. The switch is ordered with the conduit fitting for the wet location and the cover gasket protects the contacts from the splash. The wiring is terminated on the marked screws and the cover is sealed after the adjustment.

Why Seven Star LLC

Seven Star LLC supplies the United Electric H100-361 pressure switch with complete documentation, supporting instrument engineers in selecting the correct set point range and electrical configuration. We provide prompt quotations and clear lead times for process instrumentation across Oman and the GCC.

Our team supports spare switch identification and replacement programmes for existing United Electric installations in oil and gas, power, and industrial plants.

Reliability in Service

The snap-action switch mechanism of the H100-361 gives a positive transfer at the set point, avoiding the contact bounce and hunting that can occur with slow-acting contacts. The diaphragm piston element handles process pressure transients without damage, and the Type 4X enclosure protects the mechanism from weather and washdown environments.

With a generous 800 psi proof pressure and 316L stainless steel wetted parts, the switch is suitable for both clean and moderately corrosive services across a wide range of industrial applications.

Confirming the Right Replacement Switch

United Electric model codes carry the options in the part number, so a replacement should always be matched against the complete code on the nameplate rather than only the series. Before ordering, record the following from the installed unit:

• The full model number, including any suffix letters after H100-361.
• The set point, whether the switch acts on rising or falling pressure, and the reset point the process needs.
• The process connection, wetted material and the medium being sensed.
• The contact arrangement actually wired in the loop, normally open or normally closed, and the load being switched.
• Any hazardous-area marking on the label; a general purpose enclosure must not replace a certified one in a classified zone.

Installation and Set Point Adjustment

Mount the switch on a vertical, vibration-free surface or bracket and connect it through an isolation valve so it can be tested without depressurising the line. On pulsating services such as reciprocating compressor discharge, fit a snubber to protect the sensing element and prevent contact chatter. Use a proper conduit entry and seal for wet or outdoor locations so the Type 4X rating is not lost at the cable gland.

Adjust the set point on a test bench or with a calibrated hand pump and reference gauge, not by guesswork on the running plant. Approach the set point slowly, note the pressure at which the contact changes state, then reverse to confirm the reset point and the actual dead band. Record both values on the loop sheet and seal the cover after adjustment.

Periodic Testing and Troubleshooting

• Trip point has shifted: re-check against a reference gauge; confirm nothing has knocked the adjustment and that the isolation valve is fully open.
• Nuisance trips: look for pressure pulsation, a set point too close to normal operating pressure, or a loose terminal.
• No trip on test: check for a blocked impulse line or a plugged connection before replacing the switch.

Shutdown switches should be function-tested at the interval set by the plant safety or maintenance philosophy, and the as-found and as-left trip values kept on record.

Typical Duties in Oman and the GCC

In Gulf oil and gas, utilities and desalination plants the H100 series is common on compressor packages, lube and seal oil consoles, firewater systems and pump discharge protection. Seven Star LLC can source like-for-like replacements when you send the complete nameplate code, and will confirm the lead time and documentation before dispatch.

Request a Quote for PRESSURE SWITCH H100-361 United Electric, USA

For the United Electric H100-361 pressure switch, H100 pressure switch or any related control and instrumentation requirement, contact the Seven Star LLC team. Submit a formal inquiry through our RFQ page with your set point, pressure range and electrical requirements, and our specialists will respond with a detailed commercial proposal and the official United documentation.

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