VEGA VEGABAR 19 Compact Metallic Cell Pressure Transmitter

A welded metallic cell for aggressive media and higher pressure

The VEGABAR 19 is the metallic-cell counterpart of the VEGABAR 18: a compact, economical two-wire pressure transmitter for gases, vapours and liquids, built around a completely welded 316L measuring cell with a piezoresistive sensor element and internal transmission fluid. VEGA’s selection table lists the metallic versions for aggressive products. Where the 18 stops at 25 bar, the 19 spans -1 to +100 bar with a smallest range of 0.4 bar, and keeps the same small mounting dimensions and plug-type electrical connection.

Technical specifications

Welded metal cell: when it fits

Because the 316L diaphragm is welded to the process fitting and no elastomer seal is in the process path, the 19 is the version for aggressive liquids that would attack an FKM seal in a ceramic cell. The price is the oil-filled system, which is why the 19 is not front-flush and cannot be used for hygienic adapters; the VEGABAR 29 or 39 add those options and a higher process temperature of +130 °C. Compared with the 18, the 19 carries a four-times larger pressure range, so confirm that the smallest span (0.4 bar) suits your low-pressure points.

Specifying and installing

VEGA’s sheet shows the same wiring plans as the 18: M12 x 1 or ISO 4400 plug with voltage supply and signal output on the same two wires. Choose the G½ or ½ NPT thread to match the connection, confirm the 316L material and Klingersil seal against the process medium, and provide the pressure range, preferred output unit and plug type. For hazardous areas, note that the type overview shows no approval entries for the 19; use a sensor with ATEX marking instead.

The VEGABAR 19 also appears in VEGA’s documentation as a hydrostatic level option, since the same pressure cell measures the weight of a liquid column. In that role the oil-filled 316L system tolerates aggressive liquids that would stain a plastic probe, but remember that the process temperature stops at +100 °C and that the diaphragm sits at the end of the thread, so sludge or crystallising media can bridge it. Ask whether a front-flush alternative in the 29 or 39 range is warranted.

Selection checks for a VEGABAR 19 measuring point

Start by writing down the normal operating pressure, the highest pressure the line or vessel can reach during upsets, and the lowest pressure, including vacuum during draining or cooling. Choose a range that places normal operation comfortably inside the span, so the 4…20 mA signal uses a useful part of its resolution, while still covering upset conditions. Note the units the control system expects so the range can be stated clearly in the enquiry.

Then review the medium: its chemical composition, solids content and temperature, and whether it can crystallise, polymerise or deposit on surfaces. Confirm that the 316L wetted parts and the listed seal suit it, and that the process temperature stays within the transmitter's limit, including during cleaning or steam-out.

Installation and loop commissioning

Mount the transmitter at a tapping that represents the pressure you want to measure, with an isolation valve so it can be removed without draining the system. On liquid lines, a mounting position below the tapping helps keep gas pockets out of the impulse path; on gas service, mounting above the tapping helps condensate drain back to the process. Where pressure pulsation or water hammer is expected, a snubber or damping element at the tapping protects the measuring cell.

Tighten the process connection with a spanner on the fitting itself, never by turning the housing, and use a sealing method that suits the thread form you selected. Route the cable so water cannot run into the plug connector, and check that the loop supply provides enough voltage at the transmitter after allowing for cable and input resistance. At commissioning, compare the current output against a reference pressure at zero and at one or more points across the range, and record the results with the instrument tag.

Operating conditions in Oman's plants and pump stations

Water networks, desalination plants, oil and gas facilities and chemical sites in Oman often place transmitters outdoors on skids and pipe racks. Direct sun can heat a small housing well above the air temperature, so where practical shade the instrument and keep it away from hot surfaces to stay inside the ambient limits printed above. Large daily temperature swings and coastal humidity also encourage condensation in poorly sealed connectors, so fit the plug and its seal carefully and keep the protection rating intact.

Dust and sand build up on plugs and cable entries over time. Include the transmitter in routine instrument rounds: inspect the plug connector, the cable and the process connection for leaks, and check the reading against a reference at an interval that reflects how critical the measurement is. If the signal becomes unstable or shows a zero shift that cannot be explained by process conditions, replace the transmitter and investigate whether the medium has attacked the diaphragm or seal.

Documents and quotation

The official VEGA VEGABAR 19 (two-wire 4…20 mA) specification sheet (55578-EN, version 240513) is attached to this page for download and covers the technical data, dimensions and wiring summarised above.

For a quotation, tell us the medium, tank or channel dimensions, output signal, hazardous-area requirement and quantity. Seven Star LLC, an independent supplier in Muscat, will respond with availability and a commercial offer; other level instrumentation is on our site. Always verify the complete order code against VEGA’s configurator before you place an order.