Is the pressure switch connected to the DCS?

I didn’t pay attention to whether there is a difference between explosion-proof and intrinsically safe types for pressure switches; generally, using a relay for isolation is sufficient.

Are there intrinsically safe pressure switches? All those available currently have an external 220V power supply, so they cannot be made intrinsically safe

Does a pressure switch require power? I’ve never seen that. It doesn’t matter whether the pressure switch is used or not

It seems I haven’t seen a pressure switch for power supply yet. Do you have any samples? Shared hash

Who can answer me? Under normal circumstances, is the pressure switch connected directly to the DI card or DI safety barrier as a dry contact? What is the relay supposed to do? For example, with the solenoid valve at the DO point, it is the DO card that needs to control the solenoid valve through a relay, right?

A pressure switch is generally just a dry contact connected to the DCS; it seems that safety barriers are used less often in this context

If the pressure switch is a purely mechanical switch (such as a microswitch). 1. If a intrinsically safe circuit is designed with a DI safety barrier, this meets the requirements for intrinsically safe explosion protection. 2. If it is designed as a \"non-intrinsic safety\" circuit, the relay provides isolation; handle it according to your design practices. 3. DO represents the load, which are field devices such as solenoid valves; therefore, DO is a power output. It is advisable to use DO relays for isolation in order to prevent short circuits at the field level, which could cause high currents and damage the DO channels. A mechanical switch, since it has no energy storage components inside (such as inductors or capacitors), does not require an intrinsically safe certificate; a safety barrier is sufficient to create an intrinsically safe circuit. You can design it as an “intrinsically safe” or “non-intrinsically safe” circuit (such as flameproof) based on the overall requirements of the project. It is beneficial to add an isolation layer to the entry and exit signals at the site, whether it’s a safety barrier/isolator/relay. Keep the enemy out of the country’s borders. @jiaguoyun

1. The flameproof pressure switch is connected to the DCS; no intermediate relay is required – it can be connected directly to the card slot. 2. Intrinsic safety pressure switches are connected to the DCS; all intrinsic safety instruments must be equipped with safety barriers, otherwise they cannot form an intrinsic safety circuit, and such instruments lose their intrinsic safety significance and function.