Ceramic durability

By using oxide ceramics, KROHNE employs a technically superior material for electromagnetic flowmeters (EMF) and pressure-measuring devices. This material offers long-term resistance to corrosive and abrasive media and does not leach. Additionally, these ceramics are resistant to temperature shocks and completely safe against gas permeation and leakage – providing a unique combination of properties for high-performance applications across all industrial sectors.

Highlights

High-resistance to abrasion
Suited for pastes and sludges with very high solid content
The helium leakage rate of ceramic including electrodes is less than 10-7 (hPa * l)/s, this means „gas-tight“
Vacuum-resistant up to 0 hPa
High mechanical strength and form stability
0 % porosity (important for aggressive outgassing or toxic media)
Excellent surface quality and very low roughness (Ra < 0.8 µm)
Over 30 years of experience with industrial ceramic
Successful adaptions for various applications

Overview of KROHNE devices with oxide ceramics:

Flowmeters

	Installation	Size/DN	Ceramic	Electrode
OPTIFLUX 5000	Flange	15 ... 300	FZM	CERMET, sintered-in
	Sandwich	2.5 ... 15	FZM	CERMET, sintered-in
	Sandwich	25 ... 100	FZT	Platinum pin electrode with plated head, pin sintered-in
BATCHFLUX 3100	Sandwich	2.5 ... 40	FZM	Platinum pin electrode with plated head, pin sintered-in
BATCHFLUX 5500	Sandwich	15	FZM	CERMET, sintered-in
OPTIFLUX 7000	Flange	2.5 ... 40	FTM	Capacitive, on ceramic tube
	Sandwich	25	FZM	Capacitive, on ceramic tube
	Sandwich	40 ... 100	FZT	Capacitive, on ceramic tube

Ceramics used:

FZT: FRIALIT® FZT: ZrO2-stabilised Al2O3, Bending strength = 460 MPa*, E-module = 360 GPa

FZM: FRIALIT® FZM: MgO partially stabilised ZrO2, Bending strength = 500 MPa*, E-module = 200 GPa

*1 MPa = 1 N/mm2

Pressure instruments

	OPTIBAR PC 5060 Pressure transmitter	OPTIBARLC 1010 Immersion probe
Measuring ranges	0.025…100 bar	0...1 to 0...100 mH2O
Reference accuracy	<0.05 to 0.2% of URV	<±0.35% FSO
Process temperature	–40...+150°C	-40...+80°C
Process connections / material	Thread of more than 1/4¨, ASME flange, EN, DIN, JIS from DN15 in 316L, C276, Duplex, PVDF	Thread R1¨, Flange DN50, cable: TPE
Approvals	Ex ia, Ex d, SIL2/3	ATEX/IECEx Ex ia 1G, drinking water approvals (KTW, ACS)

Ceramics used:

Sapphire: 99.96 % Al2O3 ceramic, Bending strength = 630 MPa, E-module¬=¬406 GPa

Special features of flowmeters with ceramic liner:

Oxide ceramic is very resistant to acids and lyes. (Nitric acid and nitrohydrochloric acid or even hot concentrated hydrochloric acid cannot damage the oxide ceramic)
Adherence to the pressure equipment directive (DGLR)
Resistant to abrasive media: long service life especially compared to plastic liners
Fully vacuum-resistant
Dimensionally stable: high resistance to temperature shocks of up to 120 K and pressure stresses
Very high burst pressure/overload resistanct
No deposits/gumming on surface, diffusion tight and immune to leakage
Sintered-in CERMET electrodes
Leading metrological institutes use KROHNE ceramic EMFs as their master/ reference meter