Explosion Proof Pressure Switch YX18-F

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In a hazardous area, the switch itself cannot be the ignition source. The YX18-F answers that with a flameproof (Ex d) enclosure: any spark from the internal electronics is contained inside the housing so it cannot reach the gas or dust outside. On top of that protection it keeps the full digital feature set, a display, an analog output, and four independent setpoints, so a single explosion proof pressure switch can run a multi-stage interlock in a zone where an ordinary switch is not allowed.

Overview

The YX18-F is the hazardous-area member of the YX-18 series. It measures across the same wide span, up to 60 MPa, holds 0.5% FS accuracy, and adds a flameproof housing for use in classified areas. Where the standard YX-18 electronic pressure switch gives two setpoints for general plant, the YX18-F gives four, which suits the staged alarm and trip logic that hazardous processes usually demand. The exact certification marking is set per order and shown on the nameplate (ENGINEER-CONFIRM).

Flameproof protection

A flameproof (Ex d) design does not try to stop a spark inside the unit. Instead, the enclosure is built strong enough to contain an internal explosion and cool the escaping gases through its joints so they cannot ignite the surrounding atmosphere. That is the right approach for a powered device like a digital switch, which has electronics that could arc. It is a different strategy from the intrinsically-safe transmitters in our range, which limit energy instead; for a powered hazardous-area transmitter see the explosion proof pressure transmitter.

Technical specifications

Representative specifications; confirm the exact build and certification marking per datasheet.

Parameter	Specification
Control range	-0.1 to 60 MPa (vacuum, gauge, and compound)
Protection type	Flameproof (Ex d) enclosure (marking per nameplate)
Setpoints	Four switch points plus one analog output (4–20 mA)
Accuracy	≤ 0.5% FS
Switch contact rating	DC 24 V 1.2 A; AC 250 V 3 A (resistive)
Overload capacity	150% of range
Supply voltage	24 VDC ± 15% (220 VAC optional)
Process connection	M20 x 1.5 (customizable)
Medium temperature	-30 to +85 °C
Protection	IP65

Four setpoints for staged interlocks

Four independent points are the reason to choose the YX18-F over a two-point switch. A hazardous process rarely trips on one threshold; it warns, then acts, then locks out. With four points one unit can run, for example, a low-low alarm, a low warning, a high warning, and a high-high trip, each with its own setpoint and reset hysteresis set from the front. The 4–20 mA analog output runs in parallel, so the same flameproof unit also reports the continuous pressure to a control system. That folds what would otherwise be several certified devices into one, which lowers both the certified-equipment count and the wiring in the zone.

Applications

The YX18-F suits powered pressure control in classified areas:

• Oil and gas gathering, separators, and wellhead skids
• Chemical and petrochemical reactors and pump stations
• Flammable-gas compressor and storage systems
• Solvent, paint, and coating plant with explosive vapor

FAQ

What is the difference between intrinsically safe and explosion-proof?

They prevent ignition in two ways. Explosion-proof, or flameproof (Ex d), uses a strong housing that contains any internal spark and cools the escaping gases so they cannot light the atmosphere outside. Intrinsically safe (Ex i) instead limits the circuit energy so a spark can never carry enough power to ignite the gas. The YX18-F is a flameproof (Ex d) pressure switch: its electronics and contacts sit inside a certified enclosure, the common choice where the switch carries higher contact power.

When to use intrinsically safe?

Intrinsic safety suits the most hazardous zones and lets you work on the wiring live, because the energy is limited. It needs a certified barrier and low-energy circuits, which can cap contact ratings. A flameproof switch like the YX18-F is often preferred when the contacts must carry more current than an intrinsically safe loop allows, or where barriers are impractical. Match the method to your zone, your contact load, and your maintenance practice, and confirm the marking on the nameplate for your area classification.

What is a pressure switch used for?

A pressure switch opens or closes a contact when pressure reaches a set point, to start or stop equipment, trigger an alarm, or interlock a process. In a hazardous area that interlock still has to happen safely, which is why the YX18-F packages multiple set points and switching contacts inside a flameproof housing, so it can protect pumps, compressors, and burners where flammable gas or dust may be present.

Request a quote

For a hazardous-area unit, tell us:

• Area classification, gas or dust group, and temperature class
• Pressure range and whether it sees vacuum or compound
• Setpoints needed (up to four) and the interlock logic
• Outputs (switch contacts plus 4–20 mA) and supply
• Process connection (M20 x 1.5 or custom)

Ordering example: YX18-F, range 0–25 MPa, four setpoints, 4–20 mA analog, flameproof build, M20 x 1.5, 24 VDC.

Tell us the application and we configure one unit, not a shelf part. Need a certification we have not listed? Reach our application engineers.