『R290 Flow Meter: Safety Enclosures for Propane Systems; follow ATEX/Ex explosion-proof standards.』Related information(v cone flow meter|rotary gas meter|gallon meter|gear meter|metal tube rotameter|glass tube rotameter|nutating disk meter|transit time ultrasonic flow meter|wedge flow meter|pd meters|hydraulic flow meter|ultrasonic water flow meter|water flow meter|air flow meter|magnetic water flow meter|oxygen flow meter|gas flow meter|argon flow meter|air velocity meter|gasoline flow meter|fuel flow meter|ultrasonic water meter|digital water meter|nitrogen flow meter|solid flow meter|Oxygen tank flow meter|digital water flow meter|diesel fuel flow meter|steam flow meter|02 flow meter|compressed air flow meter|oil flow meter|liquid flow meter)
R290 Flow Meter: Safety Enclosures for Propane Systems
Quick Answer: R290 (propane) systems need flow meters with ATEX / Ex certified safety enclosures. A standard meter without Ex protection is a safety risk. Silver Automation Instruments supplies Coriolis mass flow meters in Ex d and Ex ia enclosures designed for R290 liquid and gas measurement. These meters give you mass flow, density, and temperature output directly, with zero need for external compensation.
Why a standard flow meter is not safe for R290
Propane is a flammable hydrocarbon classified as A3 refrigerant under ISO 817. Even a small leak inside a meter housing can create an explosive atmosphere. A standard flow transmitter with a general‑purpose aluminum or plastic housing is not rated for this. In many countries, local electrical codes and insurance requirements force you to use ATEX Zone 1 or Zone 2 equipment for any device installed in a propane line. Here is the thing: many heat pump and chiller OEMs learn this the hard way during factory acceptance testing. The inspector checks the meter label, sees no Ex marking, and stops the whole line. We have seen this on customer sites many times, especially in Southeast Asia and the Middle East.
What “safety enclosure” means in practice
A proper safety enclosure for R290 flow meters must prevent ignition of the surrounding gas. The two common protection methods we use are Ex d (flameproof) and Ex ia (intrinsic safety). Ex d enclosures are thick‑walled stainless steel or aluminum housings that can contain an internal explosion. The joint gaps are machined to tight tolerances so any hot gas escaping cools down below the ignition temperature of propane. Ex ia is different. The energy in the circuit is limited so a spark cannot occur, even under fault conditions. For R290 liquid lines on a DN15 or DN25 pipe, we often recommend a Coriolis meter with an Ex d housing because it does not need external barriers and is very robust. For remote installations where you want a compact sensor head, Ex ia with a zener barrier works well.
Which flow meter type fits R290 best
In practice, the top three contenders are Coriolis, thermal mass, and vortex. But for liquid R290 custody transfer or charge control, Coriolis wins. Here is why. A Coriolis meter measures mass flow directly. It does not care about fluid phase changes or density swings. In a propane refrigeration loop, you often have subcooled liquid close to saturation. A volume‑based meter like a turbine or vortex would need separate pressure and temperature compensation, and that adds complexity you do not want in an ATEX zone. Silver Instruments supplies a compact DN10 to DN50 Coriolis flow meter with ATEX Ex d IIC T4 or T6 certification. It outputs mass flow (kg/h), density (kg/m³), and temperature (°C) over a single 4‑20 mA HART loop. The wetted parts are 316L stainless steel and the housing is stainless steel with an epoxy coating for offshore or coastal installations. The accuracy is ±0.2 % of rate for liquid, which is more than enough for propane charge metering.
Real installation details that most engineers skip
When you install a flow meter in an R290 system, the safety enclosure is only one part. You also need to consider the cable entry. We always specify ATEX certified cable glands, usually Ex d IIC, with the corre
Typical applications and a real case
Our ATEX Coriolis meters with safety enclosures are used in propane heat pump charging stations, R290 refrigerant filling machines, and LPG blending skids. One example: a paint manufacturer in Vietnam installed their first R290 heat pump drying line last year. They needed a flow meter to control the exact propane charge into the evaporator. The pipe size was DN20, operating pressure 18 bar, liquid temperature 25 to 35 °C. We supplied a Coriolis mass flow meter in an Ex d enclosure with a local display. The 4‑20 mA output went to their PLC. The Ex rating was Ex db IIC T6 Gb, suitable for Zone 1. No issues during the ATEX inspection. They repeated the order for two more lines this year.
Contact details and how to get a quote
If you are designing an R290 system and need a flow meter with a certified safety enclosure, send us your pressure (bar), temperature (°C), pipe size (DN), and flow range. Also tell us your required ATEX zone and gas group. We will propose a specific model with a data sheet and a price within one working day.
Email: [email protected]
Tel: +86-25-68650347
WhatsApp: +86-25-52155837
WeChat: +86 15365082610
Web: flow-meter.com.au
FAQ
Can I use a standard electromagnetic flow meter for R290?
No. Electromagnetic flow meters need a conductive liquid. R290 in liquid phase is non‑conductive. Even if it worked, a general‑purpose housing is not ATEX‑rated.
What ATEX zone do I need for a propane compressor skid?
Most compressor skids in R290 systems classify the area around the gas piping as Zone 1 during normal operation. The flow meter mounted on a skid line must have at least Ex d or Ex ia protection for Zone 1, IIC gas group.
Do your Coriolis meters come with a full ATEX certificate?
Yes. Our meters carry a valid EU‑type examination certificate from a notified body. We also supply IECEx certificates for international acceptance. You get a copy of the certificate with every order.
How do you test the enclosure integrity before shipping?
Each Ex d meter undergoes a hydrostatic pressure test on the housing at 1.5 times the reference pressure defined in the standard. We also perform a helium leak test on the flamepath joints. Test reports are available on request.
Can I get a meter with a remote sensor and ATEX‑rated transmitter?
Yes. We can separate the sensor and the transmitter up to 10 meters. The sensor junction box and the transmitter housing are both independently ATEX certified. This is common in heat pump OEM lines where the PLC panel is in a safe area.
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