| 摘要 |
<p>The valve has main inlet and outlet ducts (3, 4) connected to pipes of the same diameter, an additional coupling (5) for a secondary duct, and a shutter (7) with a first aperture (15) moving perpendicular to the main ducts. The diameter of the main ducts is selected so as to allow the passage of a scraper (20), while a second aperture (16) in the shutter is shaped to prevent the scraper entering the secondary duct. The main ducts have seals between them and the shutter, and the secondary duct incorporates a rinsing jet to spray the zone between it and the main ducts.</p> |
