With Cleaner, Lubrication Added To Fluid Or Liquid Sealing At Valve Interface Patents (Class 137/237)
- Plural feed (Class 137/246.11)
- Line pressure feed (Class 137/246.12)
- Feed by or with actuation (Class 137/246.13)
- Loss control (Class 137/246.14)
- Screw feed (Class 137/246.15)
- Spring biased piston feed (Class 137/246.21)
- External pressure (Class 137/246.22)
- Gravity or capillary feed (Class 137/246.23)