直流式柱塞阀概述：
主要直流式柱塞阀的优点是介质在内流动平衡转弯拐角少。直通式流线为梯形角式流线为角形而直流式流线为波浪形，根据对三种截止阀，流阻系数的测定DN100mm，直通式截止阀流阻系数为4.1 ，DN100mm角式截止阀流阻系数为3.8，而DN100mm直流式截止阀流阻系数为0.5,阻力大大降低。
直流式柱塞阀连接、结构尺寸：
| DN(mm) | U45SM-16C、P、R U45H-16C、P、R | |||||||||||||||
| 15 | 20 | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 125 | 150 | 200 | 250 | 300 | 350 | 400 | |
| L | 130 | 150 | 160 | 180 | 200 | 230 | 290 | 310 | 350 | 400 | 480 | 600 | 622 | 698 | 787 | 914 |
| H | 180 | 200 | 220 | 260 | 280 | 310 | 350 | 390 | 430 | 460 | 550 | 650 | 750 | 860 | 980 | 1110 |
| W | 100 | 100 | 120 | 140 | 160 | 180 | 200 | 240 | 270 | 310 | 340 | 400 | 520 | 640 | 760 | 900 |
| D | 95 | 105 | 115 | 135 | 145 | 160 | 180 | 195 | 215 | 245 | 280 | 335 | 405 | 460 | 520 | 580 |
| K | 65 | 75 | 85 | 100 | 110 | 125 | 145 | 160 | 180 | 210 | 240 | 295 | 355 | 410 | 470 | 525 |
| T | 12 | 12 | 12 | 12 | 13 | 13 | 12 | 17 | 17 | 19 | 21 | 23 | 27 | 28 | 30 | 32 |
| n-φ | 4-14 | 4-14 | 4-14 | 4-18 | 4-18 | 4-18 | 4-18 | 8-18 | 8-18 | 8-18 | 8-23 | 12-23 | 12-25 | 12-25 | 16-25 | 16-30 |
| DN(mm) | U45SM-25C、P、R U45H-25C、P、R | |||||||||||||||
| 15 | 20 | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 125 | 150 | 200 | 250 | 300 | 350 | 400 | |
| L | 130 | 150 | 160 | 180 | 200 | 230 | 290 | 310 | 350 | 400 | 480 | 600 | 622 | 698 | 787 | 914 |
| H | 180 | 200 | 220 | 260 | 280 | 310 | 350 | 390 | 430 | 470 | 550 | 650 | 750 | 860 | 990 | 1110 |
| W | 100 | 100 | 120 | 140 | 160 | 180 | 200 | 240 | 280 | 310 | 340 | 400 | 520 | 640 | 760 | 900 |
| D | 95 | 105 | 115 | 135 | 145 | 160 | 180 | 195 | 230 | 270 | 300 | 360 | 425 | 485 | 550 | 610 |
| K | 65 | 75 | 85 | 100 | 110 | 125 | 145 | 160 | 190 | 220 | 250 | 310 | 370 | 430 | 490 | 550 |
| T | 14 | 14 | 14 | 15 | 15 | 17 | 19 | 19 | 21 | 25 | 27 | 31 | 33 | 36 | 40 | 44 |
| n-φ | 4-14 | 4-14 | 4-14 | 4-18 | 4-18 | 4-18 | 4-18 | 8-18 | 8-23 | 8-25 | 8-25 | 12-25 | 12-30 | 16-30 | 16-34 | 16-34 |
