General valve materials

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Commonly used trim material combinations specified in API 600 for general-purpose valves
Trim material types | Stem material type | Hardness (HB) | Sealing surface
---|---|---|---
13Cr | 200–275 | 13Cr | ≥HB250
4 | 13Cr | ≥HB750
5 or 5A | HF | ≥HB350
6 | 13Cr/NiCu | ≥HB750/≥HB175
7 | 13Cr/13Cr | ≥HB250/≥HB750
8–8A | 13Cr/HF | ≥HB250/≥HB350
18Cr-8Ni | Not specified
2 | 18Cr-8Ni | Not specified
25Cr-20Ni | 25Cr-20Ni
Nickel-copper alloy | Nickel-copper alloy
11 or 11A | Nickel-copper alloy/HF | Not specified/≥HB350
18Cr-8Ni-Mo | 18Cr-8Ni-Mo | Not specified
12 or 12A | 18Cr-8Ni-Mo/HF | Not specified/≥HB350
19Cr-29Ni | 19Cr-29Ni | Not specified
14 or 14A | 19Cr-29Ni/HF | Not specified/≥HB350

Commonly used trim material combinations
Stem material | Sealing surface material
---|---
13Cr | 13Cr/13Cr
32 | 1321/321
13Cr | 13Cr/STL
32 | 1321/STL
13Cr | STL/STL
32 | STL/STL
13Cr | 13Cr/Monel
1Cr18Ni9Ti | 1Cr18Ni9Ti/1Cr18Ni9Ti
17-4PH | STL/STL
1Cr18Ni9Ti | 1Cr18Ni9Ti/STL
17-4PH | 17-4PH/17-4PH
1Cr18Ni9Ti | STL/STL
Monel | Monel/Monel
1Cr18Ni12Mo2Ti | 1Cr18Ni12Mo2Ti/1Cr18Ni12Mo2Ti
304 | 304/304
1Cr18Ni12Mo2Ti | 1Cr18Ni12Mo2Ti/STL
304 | 304/STL
1Cr18Ni12Mo2Ti | STL/STL
304 | STL/STL
Alloy No. 20 | Alloy No. 20/Alloy No. 20
316 | 316/316
Hastelloy B | Hastelloy B/Hastelloy B
316 | 316/STL
Hastelloy C | Hastelloy C/Hastelloy C
316 | STL/STL
F51 | F51/F51
304L | 304L/304L
F51 | F51/STL
304L | 304L/STL
38CrMoALA | STL/STL
304L | STL/STL
25Cr2MoIV | STL/STL
316L | 316L/316L
4Cr10Si2Mo | STL/STL
316L | 316L/STL
4Cr14Ni14W2Mo | STL/STL
316L | STL/STL
Inconel | Inconel/Inconel

Commonly used fastener materials
Studs | Nuts | Max. temperature (°C)
---|---|---
35 | 254 | 250
40Cr18Ni9 | 0Cr18Ni9 | 600
35CrMo | 35, 45 | 250
40Cr17Ni12Mo2 | 20Cr17Ni12Mo2 | 600
35CrMo | 30CrMo | 500
25Cr2Mo1VA | 25Cr2MoVA | 600
25Cr2MoVA | 30CrMo | 550
25Cr2MoVA | 35CrMo | 600

Material pairing for bolts and nuts used in ASME valves
Bolts | Nuts | Application range | Standard designation
---|---|---|---
B7 | 2H | -29 to 425°C | ASTM A 193
B7M | 2HM | -29 to 425°C | For sulfur-resistant valves conforming to NACE standards
B16 | - | -29 to 593°C |
B8 | - | -196 to 700°C |
B8M | 8M | |
L7 | 4 | -46 to 101°C | Low-temperature valves