1. https://www.google.rs/url?sa=t&rct=j&q=&esrc=s&source=web&cd...

Slika 1 na str. 21 dokumenta na gornjoj adresi.

Iznad "Locking liquid" piše "Sperrdruckmedium".

"Sperrdruck" je isto što i "barrier pressure" (http://www.dict.cc/?s=Sperrdruck)

2. "Sperren" je na nemačkom "blokirati" (zaustaviti, zatvoriti, ustavljati...)

3. http://www.fluidsealing.com/sealingsense/Feb13.pdf

Slike i rečenica "When set up correctly, a Plan 53B pressurized seal
system has the ability to reliably deliver pressurized
barrier fluid to the mechanical seal, dissipate the heat load
absorbed into the barrier fluid from the mechanical seal
and provide an early indication of deterioration in the seal’s
performance"

4. http://en.wikipedia.org/wiki/End_face_mechanical_seal

Since almost all seals utilize the process liquid or gas to lubricate the seal faces, they are designed to leak. Process liquids and gases containing hazardous vapors, dangerous toxic chemicals or flammable petroleum must not be allowed to leak into the atmosphere or onto the ground. In these applications a second "containment" seal is placed after the primary seal along the pump shaft. The space in between these two seals is filled with a neutral or compatible liquid or gas (generally nitrogen) called a buffer seal (unpressurized) or barrier seal (pressurized)