92
A
A
A
A
A.0500.251 – IM-TL/13.00 EN (08/2009)
B) Seal plan 52 – Unpressurised double seal
Use an external reservoir to provide unpressurised buffer fluid
Reservoir
Valve
Section A-A
Section A-A
C) Seal plan 53 – Pressurised double seal
Use a pressurised external reservoir to supply clean fluid to the seal chamber.
Reservoir pressure is greater than the sealing chamber process
pressure.
Reservoir
External
pressure