Table for selecting wetted materials
Features of wetted materials
| Use and No. | Material name | Principal component | Features | Recommended environment | |
|---|---|---|---|---|---|
| 1. Lining material | 1.1 | Polyurethane rubber | Polyurethane | Synthetic elastic rubber with excellent wear resistance. It has little chemical resistance. | －40℃～＋50℃ |
| 1.2 | ETFE | Polytetrafluoroethylene resin | Synthetic polymer material containing fluorine (F) in the molecule. Although it has higher mechanical strength and abrasion resistance than PFA, it is slightly inferior in chemical resistance and heat resistance. | －40℃～120℃ | |
| 1.3 | PFA | Polytetrafluoroethylene resin | Synthetic polymer material containing fluorine (F) in the molecule. It is resistant to almost all chemicals except hot fluorine, molten alkali, and some halides. It has excellent heat resistance, low friction property, and non-adhesiveness. | Note Heat resistance is measured in heated air. -40 to + 160 ° C (Diameter 15–200 mm) -40 to + 100 ° C (Diameter 2.5–10 mm) | |
| 2. Electrode and Grounding Ring Material | 2.1 | SUS316(L) | Cr: 17%Ni: 13% Mo: 2.25% C: <0.03% Fe: remainder (components of SUS316L) | 弱アルカリ、弱酸性雰囲気で耐食性がある。無機酸、有機酸、塩化物などには使用できない。 | Water (tap water, sewage water) Weak alkali Caustic soda with less than 50% alkali, etc. |
| 2.2 | Titanium | Ti : > 99.3% | Corrosion resistance in oxidizing atmosphere. In particular, it can be used in environments where chloride ions are present. It cannot be used for sulfuric acid, nitric acid, etc. | Various chloride solutions "Ammonium chloride" "Potassium chloride" Ferrous chloride, etc. Seawater, etc. | |
| 2.3 | ASTM B574 (Hastelloy C-276 Equivalent) | Mo: 16%Cr: 16% Fe: 5% W: 4% Ni: remaining | It has a wide range of uses because it can be used in moderately oxidizing and reducing atmospheres. However, it is not used for sulfides and sulfuric acid. | Various organic acids, inorganic acids, alkalis, etc. | |
| 2.4 | Tantalum | PFA/ETFEライニング用 Ta : > 99.5% ｾﾗﾐｯｸﾗｲﾆﾝｸﾞ用 Ta : 90%W : 10% | It is corrosion resistant in a highly oxidizing and reducing atmospheres. However, it cannot be used for alkalis, fluorides, and fuming sulfuric acid. There are many cases of insulating film formation, so caution is required when using the product. | Hydrochloric acid, sulfuric acid, nitric acid, aqua, etc. | |
| 2.5 | Platinum-iridium Alloy | Pt : 90% Ir : 10% | It is corrosion-resistant to most acids and alkalis, except aqua regia and ammonium salts. However, it is expensive. | Phosphoric acid, nitric acid, hydrofluoric acid, hydrochloric acid, sulfuric acid, alkalis, etc. | |
| 2.6 | Tungsten Carbide | Wc alloy Nickel binder | Although it cannot be used for corrosive fluids, it is not easily affected by slurry noise and has excellent wear resistance. | Mud water shield, cement slurry, dehydrated sludge, earth and sand slurry, etc. | |
| 2.7 | Nickel | Mo: 15 to 17% Fe: 4 to 7% Cr: 14.5 to 16.5% Ni: remaining | Has excellent corrosion resistance against strong alkaline fluids. In particular, the corrosion resistance to sodium hydroxide and hydrofluoric acid is extremely hight compared with other metals. | Caustic soda, alkaline fluid, etc. | |
| 2.8 | Zirconium | Zr : > 99.2% | It has a wide range of corrosion resistance. The corrosion resistance to sulfides is especially high. | Copper sulfate, acid potassium hydroxide, etc. | |
Precaution on the use of selection table
The corrosive properties of the fluid in the actual operating conditions of the MagneW electromagnetic flowmeter may vary depending on the type and amount of impurities contained, temperature due to operating conditions, flow rate fluctuations, and concentration of substances. Therefore, this selection table should be used only as a guide in the first step of material selection. To select materials more accurately, field corrosion tests must be conducted under actual operating conditions to check the corrosion resistance.
Selection of lining material
Lining materials for the electromagnetic flow meter MagneW ™ include PFA, ETFE, polyurethane rubber and chloroprene rubber, with the general properties listed in the table above.
The abrasion resistance and chemical resistance of chloroprene rubber are almost the same as polyurethane rubber. Refer to the wetted material selection table for details.
Selection of materials for electrodes and grounding rings
The general characteristics of electrode materials are shown in the table above. Refer to the wetted material selection table for details. When selecting titanium and tantalum materials as electrodes, please be careful about the operating conditions.
Selection of grounding ring
The grounding ring also contacts the fluid, so it is ideal to choose the same material as the electrode material. However, the contact ring is intended to contact the fluid (to provide fluid grounding), so the corrosion resistance may be inferior to the electrode material.
Meaning of symbols in the table
The symbols in the selection table indicate the following.
| Symbol | Content |
|---|---|
| ◎ | Usable (recommended material)1), 100 ° C or less at indicated concentration |
| ○ | There are restrictions on fluid conditions such as concentration and temperature, but it can be used up to the indicated temperature |
| △ | Corrosion resistance is lower than the above symbol2), and it can only be used as a grounding ring material3) |
| × | Not available |
| No symbol | No data |
| ※1 ※2 ※3 | Some applications require special attention, so please contact us separately. |
1) The usable limit for electrode materials is a corrosion rate of 0.05 mm/year or less. Even if the corrosion rate is lower than the above, materials that may cause intergranular corrosion or stress corrosion cannot be used.
2) The usable limit for the grounding ring material is 0.5 mm/year or less.
3) Can be used up to the indicated temperature. If there is no indication, the maximum temperature is 100℃.