The BDFI /BDFC (Bellows Double Flow Induction/Convection) is an innovative modular hybrid design, created using the inboard design of a BQFD and also the outboard design of a DMSF .

Features

• Incorporates pumping ring to maximize cooling and increase seal life
• large 3/8″ ports maximize cooling and also extend seal life
• Integral deflector guides cooling barrier fluid to the most essential areas
• Sizes available from 1.000″ to 5.000″ (24mm – 125mm) in standard and also ANSI Plus gland formats

Inboard Bellows

The bellows unit is ideally situated to replace the semi-dynamic sliding elastomer of a conventional pusher seal.Also This allows the bellows design to more readily apply to thermal applications. The BDFI / BDFC is available in any AESSEAL® standard metal bellows material
and seal face combination including SHS, HHH and SAC with Carbon, Antimony Carbon,TC or SiC seal faces.

Directed Barrier Fluid Circulation

Removing the heat at the inboard faces is critical for any double mechanical seal, more so for a seal which may apply to thermal applications. The BDFI / BDFC directed barrier fluid flow path achieves effective heat removal at both sets of seal faces.

Bi-directional Barrier Fluid Circulation

Developed using the highly efficient Patented DMSF™ pumping ring, the BDFI™ will effectively and also reliably circulate barrier fluid irrespective of the direction of shaft rotation. Alternatively, in applications which use an external barrier fluid circulation device, such as a Pumppac™, or where fluid convection is required, the BDFC™ may be offered.

Fits in Thin Radial Cross Sectional Spaces

The BDFI / BDFC can install on equipment with radial cross sectional spaces as small as 0.312” (8mm). Also This typical on some smaller process pumps.

Monolithic Outboard Seal faces

Any seal design applied to thermal applications, must have the ability to seal relatively hot barrier fluids without leaking externally. Also Monolithic seal faces have excellent sealing properties in thermal applications. These faces are modular to the DMSF™ / SMSS™.

Why Outboard Monolithic Faces and not Metal Bellows?

Often seals with outboard metal bellows units will not physically fit in most types of process equipment without equipment modifications. Also Designs which may fit often compromise the number of outboard bellows convolutions thereby increasing the bellows spring rate and material stresses. Furthermore, as the outboard elastomers sited in the barrier fluid are not generally subject to chemical attack, nor does the seal have a barrier temperature necessitating a metal bellows, external metal bellows designs are not applicable for the majority of applications.

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