API 6D Check Valve

The Gold Standard in The Industry

YVI’s API 6D Check Valves are engineered for versatility and safety, meeting rigorous standards. These valves are ideal for pigging operations, with options for soft or metal seating and a welded seat ring for secure sealing. The optional counter-weight lever design offers controlled valve closure, and the optional 6FD firesafe design ensures continued operation in case of fire, reflecting YVI’s dedication to reliability and industry compliance.

API 6D Check Valve Optional Non-Slam Design Welded Disc Nut Pin Flange End Connections

API 6D Check Valve

Design Features

  • Suitable for Pigging Operations
  • Soft or Metal Seated
  • Welded Seat Ring
  • Optional Counter Weight Lever Design
  • Optional 6FD Firesafe Design
  • Optional Threaded Seat ring
  • Optional Non-slam Design
API 6D Check Valve

YVI Full Opening Check Valve are designed, manufactured and tested in accordance with API 6D and ASME B16.34, optional design to soft seated or metal seated, and soft seated type are certified to 6FD first edition, and the valve range is from 2 inch up to 48 inch, pressure rating is from 150LB up to 2500LB. With full opening design, this series of check valve can be capable for pigging applications. To prevent potential water hammer damage caused by disc closing, a dashpot device can be assembled to control the disc closing time. The function of a check valve is to prevent reversal of flow automatically and promptly.

Parts & Available Materials
No. Part Carbon Steel Stainless Steel Low Temperature NACE Service
1 Body ASTM A216 WCB ASTM A351 CF8M ASTM A352 LCC ASTM A216 WCB
2 Seat Ring ASTM A105N+HF ASTM A182 F316+HF ASTM A350 LF2+HF ASTM A105N+HF
3 Disc ASTM A216 WCB+Cr13 ASTM A351 CF8M ASTM A352 LCC+HF ASTM A216 WCB+Cr13(NACE)
4 Hinge ASTM A216 WCB ASTM A351 CF8M ASTM A352 LCC ASTM A216 WCB
5 Pin ASTM A276 410 ASTM A276 316 ASTM A276 316 ASTM A276 410(NACE)
6 Disc Nut ASTM A276 410 ASTM A276 316 ASTM A276 316 ASTM A276 410(NACE)
7 Hinge Pin ASTM A182 F6a ASTM A276 316 ASTM A182 F316 Stainless Steel
8 Plug ASTM A105N ASTM A182 F316 ASTM A350 LF2 ASTM A105N
9 Gasket SPW.SS+Graphite/RTJSS SPW.SS+Graphite/RTJ.SS SPW.SS+Graphile/RTJ.SS SPW.SS+Graphile/RTJ.SS
10 Bonnet Bolt ASTM A193 B7 ASTM A193 B8 ASTM A320 L7 ASTM A193 B7M
11 Bonnet Nut ASTM A194 2H ASTM A194 8 ASTM A194 7 ASTM A194 2HM
12 Cover ASTM A216 WCB ASTM A351 CF8M ASTM A352 LCC ASTM A216 WCB

Material list, other materials available/provided.

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Dimension Data

Class 150

NPS in 2” 3” 4” 6” 8” 10” 12” 14” 16” 18” 20” 24” 26” 30” 36” 40” 48”
D in 2.01 2.99 4.02 5.98 7.99 10 12.01 13.27 15.24 17.24 19.25 23.27 25 29.02 34.49 38.5 45.98
mm 51 76 102 152 203 254 305 337 387 438 489 591 635 737 876 978 1168
L-L1 (RF-BW) in 7.99 9.49 11.5 14.02 19.49 24.49 27.52 30.98 34.02 38.5 38.5 50.98 50.98 60 77.01 77.01 100
mm 203 241 292 356 495 622 699 787 864 978 978 1295 1295 1524 1956 1956 2540
H in 5.51 5.51 7.01 11.02 14.1 15.12 17.13 17.2 18.98 21.06 22.64 24.21 26.93 31.02 36.57 42.91 54.76
mm 140 140 178 280 359 384 435 437 482 535 575 615 684 788 929 1090 1391
WT kg 19 30 42 84 150 230 332 368 490 632 846 1370 1450 2120 2980 4870 7950

Class 300

NPS in 2” 3” 4” 6” 8” 10” 12” 14” 16” 18” 20” 24” 26” 30” 36” 40” 48”
D in 2.01 2.99 4.02 5.87 8.11 10 12.01 13.27 15.24 17.24 19.25 23.27 25 29.02 34.49 38.5 45.98
mm 51 76 102 149 206 254 305 337 387 438 489 591 635 737 876 978 1168
L-L1 (RF-BW) in 10.51 12.52 14.02 17.52 20.98 24.49 27.99 32.99 34.02 38.5 40 52.99 52.99 62.76 82.01 82.52 100
mm 267 318 356 445 533 622 711 838 864 978 1016 1346 1346 1594 2083 2096 2540
H in 9.61 7.56 8.39 11.1 12.32 15.28 17.01 19.06 20.87 23.31 25.12 28.35 30.12 34.17 40.16 46.46 100
mm 148 192 213 282 313 388 432 484 530 592 638 720 765 868 1020 1180 2540
WT kg 22 42 71 127 212 297 370 490 615 735 980 1815 2115 2460 4730 6780 13900

Class 600

NPS in 2” 3” 4” 6” 8” 10” 12” 14” 16” 18” 20” 24” 26” 30” 36” 40”
D in 2.01 2.99 4.02 5.87 7.99 10 12.01 13.27 15.24 17.24 19.25 23.27 25.16 29.02 34.49 38.5
mm 51 76 102 149 203 254 305 337 387 438 489 591 639 737 876 978
L-L1 (RF-BW) in 11.5 14.02 17.01 22.01 25.98 30.98 32.99 35 39.02 43 47.01 55 57.01 65 82.01 82.52
mm 292 356 432 559 660 787 838 889 991 1092 1194 1397 1448 1651 2083 2096
L2 (RTJ) in 11.61 14.13 17.13 22.13 26.14 31.14 33.11 35.12 39.13 43.11 47.24 55.39 57.52 65.51 – –
mm 295 359 435 562 664 791 841 892 994 1095 1200 1407 1461 1664 – –
H in 6.18 7.48 8.66 12.62 17.6 16.57 18.62 20.94 28.7 26.3 32.3 38.2 33.46 34.61 37.68 43.78
mm 157 190 220 320.5 448 421 473 532 730 668 820 971 850 879 957 1112
WT kg 36 61 116 217 420 570 788 1020 1440 1695 2600 3600 4715 5880 10450 15400

Class 900

NPS in 2” 3” 4” 6” 8” 10” 12” 14” 16” 18” 20” 24”
D in 2.01 2.99 4.02 5.98 7.99 10 12.01 12.76 15.24 16.73 18.62 22.52
mm 51 76 102 152 203 254 305 324 387 425 473 572
L-L1 (RF-BW) in 14.49 15 17.99 24.02 29.02 32.99 37.99 40.51 44.49 47.99 52.01 60.98
mm 368 381 457 610 737 838 965 1029 1130 1219 1321 1549
L2 (RTJ) in 14.61 15.12 18.11 24.13 29.13 33.11 38.11 40.88 44.88 48.5 52.52 61.73
mm 371 384 460 613 740 841 968 1038 1140 1232 1334 1568
H in 6.38 12 7.95 16.7 16.34 18.03 19.84 27 30.7 27.87 30.39 35.31
mm 162 305 202 423 415 458 504 686 781 708 772 897
WT kg 76 82 160 272 548 944 1560 1660 2060 3020 3750 5400

Class 1500

NPS in 2” 3” 4” 6” 8” 10” 12” 14” 16” 18” 20” 24”
D in 2.01 2.99 4.02 5.75 7.64 9.49 11.38 12.36 14.25 16.02 17.99 21.02
mm 51 76 102 146 194 241 289 314 362 407 457 534
L-L1 (RF-BW) in 14.49 18.5 21.5 27.76 32.76 39.02 44.49 49.49 54.49 60.51 65.51 76.5
mm 368 470 546 705 832 991 1130 1257 1384 1537 1664 1943
L2 (RTJ) in 14.61 18.62 21.61 27.99 33.11 39.37 45.12 50.24 55.39 61.38 66.38 77.64
mm 371 473 549 711 841 1000 1146 1276 1407 1559 1686 1972
H in 7.24 9.84 14.7 19.8 23.9 17.8 29.9 22.32 24.53 27.09 29.21 33.94
mm 184 250 373 502 608 452 760 567 623 688 742 862
WT kg 76 128 230 506 942 1750 2350 2950 3600 5500 6800 10150

Class 2500

NPS in 2” 3” 4” 6” 8” 10” 12”
D in 1.73 2.52 3.5 5.24 7.13 8.86 10.51
mm 44 64 89 133 181 225 267
L-L1 (RF-BW) in 17.76 22.76 26.5 35.98 40.24 50 55.98
mm 451 578 673 914 1022 1270 1422
L2 (RTJ) in 17.87 22.99 26.89 36.5 40.87 50.87 56.89
mm 454 584 683 927 1038 1292 1445
H in 10.71 12.2 15.2 17.13 19.61 22.52 27.13
mm 272 310 386 435 498 572 689
WT kg 145 260 480 1020 1700 3110 3700

All technical data is subject to change without notice.