Pressure transmitters for oil and gas applications must meet a combination of explosion protection, material and functional safety requirements. Hazardous-location approval, NACE MR0175 sour service compliance, SIL rating and the exact wetted materials all need to match the installation. This guide covers the key criteria and leads directly into the sensor selector.
Pressure transmitters for oil and gas applications must typically meet a combination of explosion protection approvals, material standards and functional safety requirements. The specific combination depends on the installation type, location and operator specification.
Typically required for European and international installations in classified hazardous areas. Many onshore oil and gas process areas are classified as Zone 1 or Zone 2, depending on the area classification. North American projects usually require FM, CSA, UL or cULus hazardous-location approval instead.
Material standard for equipment in H₂S-containing (sour service) environments. For sour service, wetted materials must be selected and documented according to NACE MR0175 / ISO 15156 for the specific service conditions. Verify material grade, hardness, heat treatment and certificate scope for all wetted parts.
Safety Integrity Level assessment for use in safety instrumented systems (SIS). SIL 2 is commonly specified for emergency shutdown and process safety applications in oil and gas.
North American hazardous-location approvals for onshore oil and gas in the US and Canada. Class I Division 1 or Division 2, depending on the area classification. Some international projects specify both North American and ATEX/IECEx approvals, depending on asset location and operator requirements.
Hydrogen sulphide (H₂S) in process fluids causes sulphide stress cracking (SSC) in susceptible materials. NACE MR0175 / ISO 15156 defines the material requirements for wetted components in sour service. For pressure transmitters, this means the diaphragm, process connection and wetted seals must all comply.
Common NACE-compliant wetted materials include 316L stainless steel (within hardness limits), Hastelloy C276, Inconel and selected duplex stainless steels. 316L stainless steel may be acceptable in some sour service applications, but must be verified against the specific H₂S partial pressure, chloride content, pH and temperature. Always request material certifications (EN 10204 3.1 or 3.2) and verify compliance with the applicable NACE/ISO requirements.
| Criterion | What to check |
|---|---|
| Hazardous area approval | ATEX/IECEx for European and international installations. FM/CSA for North American onshore. Offshore installations may additionally require classification society approval (DNV, ABS, LR). |
| Sour service | If H₂S is present, verify NACE MR0175 / ISO 15156 compliance for all wetted parts. Request material certificates. Verify hardness values against NACE requirements. |
| SIL rating | If the transmitter is part of a safety instrumented function, verify the SIL capability (SIL 1, SIL 2 or SIL 3). SIL-rated variants require specific documentation including FMEDA and proof test intervals. |
| Output signal | 4–20 mA 2-wire with HART is the dominant standard for oil and gas process measurement. Foundation Fieldbus and PROFIBUS PA are used in some facilities. Verify the control system compatibility. |
| Wetted materials | 316L stainless for standard service. Hastelloy C276 for aggressive or sour media. Verify compatibility with the specific process fluid, including H₂S concentration, CO₂, chlorides and temperature. |
| Process connection | Flanged connections common for process lines. G1/2 and NPT for instrument manifolds. Flush diaphragm for viscous crude or fouling media. |
| Ambient conditions | Onshore oil and gas sites can see extreme temperature ranges. Verify the ambient and process temperature specifications. Desert sites may require high-temperature versions; Arctic or deepwater sites require low-temperature ratings. |
ATEX approval for a sensor series does not automatically cover all variants. The protection concept, gas group, temperature class and device configuration must all match the installation. Always verify against the actual certificate, not just the product brochure.
316L stainless steel can be NACE MR0175-compliant within specific hardness limits, but not all 316L components meet these requirements. Request material certificates and verify hardness values, especially for castings and fittings.
A standard process transmitter cannot be used in a safety instrumented function without a valid SIL assessment. SIL-rated transmitters come with FMEDA documentation and defined proof test intervals. Verify the SIL documentation covers the intended architecture (1oo1, 1oo2 etc.).
The process diaphragm material is visible on the datasheet, but seals, O-rings and wetted fasteners may use different materials. Request the complete wetted materials declaration and verify against the process fluid composition.
Verify before specifying: Always confirm hazardous area approval, NACE compliance, SIL documentation, wetted materials and temperature range against the official certificates and manufacturer specifications. Pressure Selector provides a shortlist for further evaluation — it does not replace engineering review or certification assessment.
For promising matches, use Request Info on any result to prepare a supplier inquiry based on your application requirements.
Pressure Selector converts application requirements — such as ATEX/IECEx approval, NACE MR0175 compliance, SIL rating, pressure range, output signal, wetted materials and process connection — into a structured shortlist of matching pressure transmitters and sensors.
Coverage includes selected pressure transmitters for oil and gas applications from manufacturers such as Yokogawa, ScanSense, Ashcroft, Wika, Althen, TE Connectivity and others. Availability of NACE compliance, SIL rating, specific ATEX variants and material certificates depends on the selected series and device configuration.