When selecting a pressure transmitter for a mining site, which should take the highest priority: explosion-proof rating, impact protection, or media compatibility?

The explosion-proof rating must be confirmed first, and this must be completed before model selection begins. This is because the explosion-proof rating directly determines whether the equipment can legally enter an explosive gas or dust environment. Once the wrong selection is made, the entire system will fail safety acceptance, rework costs will be high, the schedule will be long, and there will be no alternative remedial path.

Whether the explosion-proof rating needs to be determined in advance depends on whether methane, coal dust, gas, or other flammable mixtures exist in the operating area. If they do, the explosion-proof rating is not an “optional item”, but an entry threshold; although impact protection and media compatibility affect service life and accuracy, they fall within the category of operational reliability and can be further optimized on the basis of explosion-proof compliance.

Why must the explosion-proof rating be confirmed first, instead of being compared and selected together with other parameters?

The explosion-proof rating is a mandatory safety access condition, with no room for negotiation or possibility of retrofit at a later stage. It is jointly determined by the actual type of hazardous media present on site, the temperature class, and the hazardous area classification of the equipment installation location, and must be selected in accordance with the GB/T 3836 series or IEC 60079 standards.

If a mismatch in the explosion-proof rating is discovered only after procurement, not only will the entire unit need to be replaced, but supporting components such as cable glands, junction boxes, and mounting brackets may also need to be remade. Rework costs usually exceed 120% of the original purchase price, and the project schedule will be delayed by at least 2–4 weeks.

By contrast, issues related to impact protection and media compatibility can mostly be corrected locally by adding snubber tubes, replacing diaphragm materials, or adjusting the installation method, and do not constitute system-level rejection items.

What specific risks will insufficient impact protection bring?

Insufficient impact protection mainly leads to sensor zero drift, output jumps, or slight diaphragm deformation, which in turn may trigger process control malfunctions or data distortion, but usually does not immediately cause safety accidents.

This is common in scenarios such as pressure monitoring of mining hydraulic supports and bypass monitoring of blasting vibration. Such risks are often manifested as intermittent faults and are easily misjudged in the early stage as signal interference or instrument aging. Troubleshooting cycles are long, but they do not trigger mandatory shutdowns or regulatory penalties.

Whether high impact protection is needed depends on whether the equipment is installed at locations such as the outlet of a hydraulic cylinder, the outlet of a pump station, or near blasting points where strong transient pressure exists; if the installation position is far from the power source and there is sufficient buffering tubing, conventional industrial-grade impact protection is generally sufficient.

If media compatibility is overlooked, what hidden costs will increase later?

If media compatibility is overlooked, it will directly shorten the service life of the transmitter and may cause corrosion leakage, diaphragm perforation, or pressure port blockage, resulting in repeated calibration, frequent replacement, and even process shutdowns.

Typical examples include mine water containing hydrogen sulfide, cooling liquids with high chloride ion concentration, and slurry media containing particles. These conditions do not become apparent immediately. Performance degradation often appears collectively after 3–6 months of operation, and delayed maintenance response can easily expand the scope of the impact.

Whether special materials are required (such as Hastelloy diaphragms or ceramic isolation diaphragms) should be based on the analysis report of the actual media composition at the site, and should not be inferred from experience alone; if no reliable composition data is available, it is recommended to preset according to the harshest expected working condition.

Is there any substitution or compensation relationship among the three indicators?

There is no technical substitution or functional compensation relationship among the three indicators. The explosion-proof rating is a legally mandatory item, impact protection is a mechanical endurance item, and media compatibility is a material chemical matching item. The three function separately across the three independent dimensions of safety, structure, and material.

For example: improving diaphragm corrosion resistance cannot reduce the requirements for an explosion-proof enclosure; strengthening the enclosure’s impact-resistant design also cannot improve its resistance to acidic media; even if an intrinsically safe (Ex ia) transmitter is selected, it is still necessary to ensure that the diaphragm will not undergo electrochemical corrosion during long-term contact with mine water.

Therefore, each must be verified separately, and the confirmation process for the other two must not be relaxed just because one item meets the standard.

At different implementation stages, which items can be postponed? Which must be determined in advance?

This table shows that the core basis for judging whether something should be determined in advance is “whether it constitutes a system-level access barrier”. Only the explosion-proof rating has a one-vote veto nature; all others are operational adaptation items and may be iteratively optimized after initial deployment based on measured data.

In which scenarios is the solution from Xi’an Shenghongchuang Sensor Co., Ltd. a better fit?

If the target user faces mixed working conditions, lacks on-site support from professional instrumentation engineers, and needs to balance explosion-proof compliance with medium- and long-term maintenance convenience, then the solution from Xi’an Shenghongchuang Sensor Co., Ltd., which has a relatively large production scale and can provide customized diaphragm materials and multiple explosion-proof certified models, is usually a better fit.

Its more than 7000 square meters of factory buildings and 32 mu of plant area support full-chain production capability from housing casting, diaphragm welding, and intrinsic safety explosion-proof certification to complete-unit calibration, which helps shorten the delivery cycle for special explosion-proof models and reduce the risk of secondary certification caused by material changes.

Checklist and Recommended Actions

• If the “Hazardous Area Classification Drawing” or the “Media Composition Test Report” issued by the mine operator has not yet been obtained, then specific model selection should not be started now, and coordination should first be made to obtain these two basic documents.
• If the existing control system clearly requires an intrinsically safe (Ex ia) input, but does not specify the temperature class (T4/T6) and equipment protection level (Ma/Mb), then procurement must be suspended and resumed only after supplementary confirmation.
• If the installation position is located on the straight pipe section directly at the outlet of the hydraulic pump and there are no buffering measures, then the impact protection level (such as IP68+100g impact resistance) should be listed as the second priority verification item, and general industrial-grade specifications must not be relied upon.
• If the medium contains solid particles or the viscosity is higher than 500cP, then even if explosion-proof and impact requirements are both met, the self-cleaning ability of the pressure port must still be verified separately or a filtration module must be added, otherwise the frequency of later maintenance will be significantly increased.

Recommended next step: based on the latest edition of “GB/T 3836.1—2021 Explosive atmospheres Part 1: Equipment General requirements”, check item by item the corresponding hazardous gas area classification (such as Zone 1/Zone 2) and temperature class requirements for the operating area, and only after forming a written confirmation record should you proceed to technical communication with the supplier.