Different LCB Valve and LCC Valve
Different LCB Valve and LCC Valve
LCB in valve means low temperature carbon steel such as forged ASTM A350 LF2 and it’s cast equivalent ASTM A352 LCB. Higher grades such as ASTM A352 LCC and Alloy (Nickel) based forged carbon steel A350-LF3 and it’s cast equivalent A352-LC3 are also available on an indent basis. LF2 and LCB low temperature carbon steels are suitable for continuous service down to -46ºC, up to 345ºC. However alloy – Nickel based carbon steels like LCB, LF3, etc. are rated to lower temperatures (see below table). For cryogenic service colder than these temperatures austenitic stainless grades such as 304, 316 (CF8, CF8M) are required.
Low Temperature Steel Types
| Steel Type | Grade (forging) | Grade (cast) | Composition | Min Temperature |
|---|---|---|---|---|
| Austenitic | A182, F316 | A351 CF8M | 18Cr, 8Ni, 2Mo | -196ºC |
| Nickel Based Steel | A350 LF3 | A352 LC3 | 3 1/2Ni | -101ºC |
| Nickel Based Steel | NO EQUIV | A352 LC2 | 2 1/2Ni | -73ºC |
| Low Temp Carbon Steel | NO EQUIV | A352 LC1 | 0.5Mo | -59ºC |
| Low Temp Carbon Steel | A350 LF2 | A352 LCB | Carbon Steel | -46ºC |
| Low Temp Carbon Steel | NO EQUIV | A352 LCC | Carbon Steel | -46ºC |
Applications
Other than temperature capabilities, LF2 and LCB are suitable for the same standard service applications as outlined as outlined at this website for A105 and WCB such as steam, hydrocarbons and general industrial services. The main difference between LF2/ LCB and A105/WCB is that LF2/LCB is Charpy impact tested at -46ºC. For this reason, Global Supply Line stocks LF2 and LCB valves dual conforming to A105 and WCB. We also stock A352-LCC triple conforming to WCB, LCB and WCC.
Carbon Steel Grades – Ex Stock
| Material Group | Common Name | Material Type | UNS | Forging Spec. | Casting Spec. Equivalent | DIN | DIN W. No | Application |
|---|---|---|---|---|---|---|---|---|
| Carbon Steel | CS | C-Si | K03504 | A105 | A216-WCB | C22.8 DIN 17243 | 1.0460 | General non-corrosive service from -29ºC (-20ºF) to 425ºC (800ºF) |
| Carbon Steel | CS | C-Si | K03504 | A105N | A216-WCC | C22.8 DIN 17243 | 1.0460 | General non-corrosive service from -29ºC (-20ºF) to 425ºC (800ºF)(Slightly higher pressure ratings than WCB) |
| Low Temperature Carbon Steel | LTCS | C-Mn-Fe | K03011 | A350-LF2 | A352-LCB A352-LCC | TSTE 355 DIN 18103 | 1.0566 | General non-corrosive service from -46ºC (-50ºF) to 340ºC (650ºF), LF2 -46ºC ~ 425ºC |
| Low Temperature Alloy Steel | Nickel Steel | 3.1/2Ni | K32025 | A350-LF3 | A352-LC3 | 10Ni14 | 1.5637 | -101ºC (-150ºF) to 340ºC (650ºF) |
ASTM Carbon Steel Types Key Chemical Properties
| KEY PHYSICAL PROPERTIES | CAST CARBON STEEL |
FORGED |
|---|---|---|
| 0.30/0.35 C Max | A216-WCB | A105 |
| 0.25 C Max | A216-WCC | |
| LOW TEMPERATURE STEEL | ||
| 0.25/0.30 C Max | A352-LCB | A350-LF2 |
| 0.5 Mo | A352-LC1 | |
| 2.5 Ni | A352-LC2 | |
| 3.5 Ni | A352-LC3 | |
| C-MN-Si (0.25 Max) | A352-LCC | A350-LF3 |
| C-MN-Si-V (1.15~1.50 Mn) | A350-LF6 | |
Chemical & Mechanical Composition A350-LF2†
| CHEMICAL PROPERTIES | MECHANICAL PROPERTIES | |
|---|---|---|
| C 0.30 Max | TS Min psi (Mpa) | 70,000 (485) |
| Mn 0.60 – 1.35 | YS Min psi (Mpa) | 36,000 (250) |
| Si 0.15 – 0.30 | EL (2″ Min) | 22% |
| P 0.035 Max | RA Min | 30% |
| S 0.040 Max | Hardness, Bhn | Max 197 |
| Cr 0.30 Max | -50ºF Charpy | Min Impact |
| Ni 0.40 Max | Energy F t/Lb (J):- | |
| Mo 0.12 Max | Set of 3 Specimen* | 15 (20) |
| V 0.08 Max | For One Specimen | 12 (16) |
| Cb 0.02 Max | ||
| Cu 0.04 Max | ||
| Pb 0.02 Max | ||
| Total Residuals = 0.50 | ||
ASTM A352 LCBstandards cover the use of LCB in valves,This specification covers carbon steel castings for valves, fittings, flanges and other pressure-containing parts for low temperature service, valve type including:
- Ball valves
- Check valves
- Wafer check valves
- Gate valves
- Globe valves
- Needle valves
- Plug valves
- Strainers
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LCB vs. LCC
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ASTM Grade LCB Steel vs. ASTM Grade LCC Steel
Both ASTM grade LCB steel and ASTM grade LCC steel are iron alloys. Both are furnished in the normalized and tempered condition. Their average alloy composition is basically identical. There are 30 material properties with values for both materials. Properties with values for just one material (1, in this case) are not shown.
For each property being compared, the top bar is ASTM grade LCB steel and the bottom bar is ASTM grade LCC steel.
LCB and LCC carbon steel low-temperature gate valves are American standard low-temperature carbon steel gate valves. Low-temperature carbon steel is a low-carbon alloy steel with a temperature range of -46 °C~+343 °C and is generally used to manufacture valves. In the machinery industry, LCB is also used to refer to low temperature carbon steel.
Its chemical composition: C≤0.30; Si≤0.60; Mn≤1.00; P≤0.040; S≤0.045; impurity elements Cr≤0.5; Mo≤0.20; V≤0.03; Ni≤0.50; Cu≤0.30; total amount of impurities≤ 1%.
Note: For every 0.01% decrease in C, Mn can be increased by 0.04%, but Mn cannot be higher than 1.28%.
Mechanical properties: Rm450-620MPa, Rel≥240MPa, A≥24%, Z≥35%.
Low-temperature carbon steel gate valves are generally suitable for low-temperature media such as methane, liquid natural gas, hexene, carbon dioxide, liquid ammonia, liquid oxygen, liquid nitrogen, and liquid hydrogen.
