WIKA 212.20 Bourdon Tube Pressure Gauge, Stainless Steel Case

Overview

The WIKA 212.20 is a mechanical Bourdon tube pressure gauge with a stainless steel case, designed for industrial applications that need high accuracy and a dial that is easy to read, also from a distance. Depending on the scale range, its wetted parts are copper alloy or stainless steel, and it is manufactured and qualified to EN 837-1 and ASME B40.100. The gauge is offered in nominal sizes of 100 mm and 160 mm, with scale ranges from 0 to 0.6 bar up to 0 to 1,000 bar, and vacuum and compound ranges.

Seven Star LLC supplies the WIKA 212.20 to MEP contractors, OEMs, facility managers and industrial plants across Oman and the GCC, with engineering support in Muscat. WIKA lists machine building, plant construction, building services and refrigeration as its main applications, which makes it one of the gauges most often requested for chilled water pressure gauges in HVAC plant rooms in the region.

Measurement Principle

Inside the gauge, a Bourdon tube with an oval cross-section is fixed at the process connection and free at its tip. Pressure inside the tube tends to straighten it, and the small movement at the tip is amplified by a copper alloy movement that turns the pointer over the dial. Ranges below 100 bar use a copper alloy tube, while ranges of 100 bar and above use a 316L stainless steel tube, in C-type or helical form. The deflection is proportional to pressure, so the reading follows a linear scale without any power supply.

The WIKA 212.20 achieves accuracy class 1.0 to EN 837-1, or ±1 % of span (grade 1A) to ASME B40.100, with a temperature error of no more than ±0.4 % of full scale per 10 °C deviation from 20 °C. For applications with pulsation, a silicone-damped movement or a brass restrictor of 0.6 or 0.3 mm can be specified to steady the pointer.

Engineering Design of the WIKA 212.20

The case is stainless steel with a natural finish, closed by a bayonet bezel in stainless or polished stainless steel. As a safety function, the case has a blow-out device so that, in the event of a failure, overpressure can escape away from the dial. The window can be instrument glass, laminated safety glass or polycarbonate. The modular design allows many combinations of process connections, nominal sizes and scale ranges, and the case meets IP54 ingress protection.

Process connections are lower mount or lower back mount, in G 1/4 B, G 3/8 B, G 1/2 B or M20 x 1.5 to EN 837-1, R 1/4 to R 1/2 to ISO 7, or 1/4 to 1/2 NPT. For panel installation the WIKA 212.20 can be fitted with a surface mounting flange, a panel mounting flange or a triangular profile ring with mounting bracket. Further versions include oil- and grease-free, oxygen service and silicone-free builds, and pointer options include knife edge or adjustable pointers and red mark or drag pointers.

Key Features

The WIKA 212.20 is a durable, cost-effective gauge for general industrial service:

• Stainless steel case with blow-out device, combined with copper alloy or 316L measuring systems.
• Accuracy class 1.0 with large NS 100 and NS 160 dials for reading at a distance.
• Scale ranges from 0 to 0.6 bar to 0 to 1,000 bar, plus vacuum and compound ranges, in bar, psi, kg/cm², kPa or MPa.
• Medium temperature options of -20 to +80 °C or -20 to +150 °C, and ambient -40 to +60 °C.
• Pressure limitation of full scale steady, 0.9 x full scale fluctuating and 1.3 x full scale short time.
• Silicone-damped movement option for pulsating pressures.
• DNV approval for shipbuilding and offshore use.
• Oil- and grease-free, oxygen and silicone-free versions on request.

Industrial Applications

In HVAC and district cooling plants in Muscat and across the GCC, the WIKA 212.20 is installed on chiller evaporator and condenser connections, pump suction and discharge, strainers, expansion vessels and heat exchangers, where operators compare inlet and outlet pressures to spot fouling or pump problems. Hospitals, hotels, malls and airports specify it on their chilled water, condenser water and domestic water systems, wherever a clear, reliable local reading is needed next to the equipment.

Machine builders and skid fabricators use the WIKA 212.20 on hydraulic power units, compressors, water treatment skids and general utility headers. Its DNV approval also makes it suitable for vessels and offshore support equipment operating out of Sohar, Duqm and Salalah. Seven Star LLC supplies the gauge in the range and connection required, and can recommend a stainless steel wetted model where the medium is not compatible with copper alloy.

For aggressive media, see the all stainless steel WIKA 232.50 Bourdon tube pressure gauge.

Technical Specifications

Specifications for the WIKA 212.20 are taken from WIKA data sheet PM 02.01 (05/2025):

How to Order

For a WIKA 212.20 quotation, a gauge schedule is the easiest starting point: list each tag with its dial size, range, thread and mounting, plus the medium it will see. Seven Star LLC will check copper alloy compatibility, group identical gauges to shorten delivery, confirm availability and lead time for Oman and the GCC, and attach the WIKA data sheet for the consultant. Related products on our site include the WIKA 233.50 liquid-filled pressure gauge, the WIKA PSM01 compact pressure switch and the Ashcroft 1279 Duragauge pressure gauge.