How to choose a proper type caustic soda flow meter?

Caustic soda, the chemical formula is NaOH, commonly known as sodium hydroxide, caustic soda, is a kind of aggressive alkali with strong corrosivity.

Caustic soda is highly corrosive. If you want to measure the flow of caustic soda solution, it is a tough job. Turbine flowmeter, Vortex flowmeter is easily corroded by NaOH. We generally choose electromagnetic flowmeter to measure the caustic soda flow.

Magnetic flow meter is based on Faraday’s low of induction, it can measure conductive liquid flow rate, and due to caustic soda is conductive, we can use mag meter to measure caustic soda. Besides, it can measure portable water, milk, juice, waste water and so on. It is now a kind of widely used flow meters.

Choose the suitable caustic soda flow meter. We need to provide the following parameters to the electromagnetic flowmeter manufacturer:

NaOH concentration and operating temperature

Different concentrations and working temperatures of sodium hydroxide have different degrees of corrosively. We choose different electrode materials and lining materials. Please refer to below tables:

concentration	Temperature	Electrodes material					Liner
		316L	Hastelloy c	Titanium	Tantalum	Platinum	PTFE	PFA
10~20%	Room temperature	√		√		√	√	√
34~50%	Room temperature			√		√	√	√
10~20%	150 ℃			√		√	√	√
30~50%	70~150 ℃					√	√	√
50%	180 ℃					√	√	√
60~100%	~150 ℃					√	√	√

Sodium hydroxide flow range and pipe line size

The flow meter sensor size is based on the flow range. See the following table for reference:

Size(DN)	Pressure	Min flow range velocity(0-0.5)m/s	Max Flow range velocity(0-10)m/s
10	4.0 Mpa	(0-2.25)L/min	(0-45)L/min
15	4.0 Mpa	(0-5)L/min	(0-100)L/min
20	4.0 Mpa	(0-7.5)L/min	(0-150)L/min
25	4.0 Mpa	(0-10L)/min	(0-200)L/min
32	4.0 Mpa	(0-20L)/min	(0-400)L/min
40	4.0 Mpa	(0-30L)/min	(0-600)L/min
50	4.0 Mpa	(0-3)m³/h	(0-60)m³/h
65	4.0 Mpa	(0-6)m³/h	(0-120)m³/h
80	4.0 Mpa	(0-9)m³/h	(0-180)m³/h
100	1.6 Mpa	(0-12)m³/h	(0-240)m³/h
125	1.6 Mpa	(0-21)m³/h	(0-420)m³/h
150	1.6 Mpa	(0-30)m³/h	(0-600)m³/h
200	1.6 Mpa	(0-54)m³/h	(0-1080)m³/h

Flow meter process connections, especially flange standards

The flange standard Silver Automation Instruments provide is DIN standard. If the ANSI standard and JIS standard are required, please specify to the electromagnetic flowmeter supplier at the time of inquiry.

Flow meter function

Caustic soda flow meters have different functions, below we list the normally request functions:

• RS 485(Modbus RTU)
• Hart Protocol
• Profibus DP
• Remote display or integral type display
• Protection level, such as IP 65 or, IP67 or IP68?

Provide power supply for the magnetic flow meter

For caustic soda flow meter, we have 3 power supply types

220V AC±20%

24V DC

Battery power supply (3.6V lithium battery)

Welcome to contact us to obtain more technical specifications about caustic soda flow meters .