Product Name: Pneumatic High Vacuum Angle Valve Dn500 Model NO.: GDQ-S500 Trademark: Pioneer Transport Package: Plywood Case Specification: CE, TS, ISO9001-2008, SGS Origin: China HS Code: 8481804090 Product Description 1. GDQ pneumatic high vacuum baffle valve relies on the electromagnetic directional valve to change the gas flowing direction and control the cylinder action to open or close the valve to turn on or cut off the airflow in the vacuum pipeline. The applicable media is air and non-corrosive gases.It has two types, one is angle-through (GD-J) and the another is with flange style of pre-pump (GD-S). And it has two forms in seal, combinatorial rubber seal rings seal and bellows seal. That it is the bellows seal style after the product type No. with "b".In order to get the control automatically and reasonably please elect the signal feedback device. It don't have the signal feedback device when the product leave the factory.