SD Mechanical Seal

Cartridge dual welded metal bellows “o-rings free” mechanical seal (API 682, Type C) 

Description

Cartridge dual welded metal bellows mechanical seals of SD family are mainly designed for sealing hot hydrocarbons at oil refineries and petrochemical plants. SD family seals correspond to API682, type C seal. Both tandem and double seals are available, with stationary or rotary metal bellows. Also, contacting wet and dry running outboard seal versions are available.

SD family seals are used for the same applications as the followings seals:
MFLWT 80 by Burgmann, Germany
BXRH/BXHH by Flowserve, USA
604/606/609/3609/ECS by John Crane, USA
34 family by EKK Eagle, Japan
(see note below)

Advantages

  • SD seals utilize welded metal bellows design without a single o-ring which ensures a broad temperature range of from -70°C and up to +425°C - ideal for sealing hot hydrocarbons at oil refineries and petrochemical plants.
  • Due to the fact that many fluids at oil refineries and petrochemical plants like hydrogen sulfide or MEA attack viton o-rings, SD seals are widely used instead of o-ring seals.
  • Metal bellows is highly resistant to cocking as compared to mechanical seals with o-rings.
  • Metal bellows mechanical seals are balanced which reduces heat buildup.
  • Both stationary and rotary metal bellows are available.
  • Almost the only stationary bellows tandem seal on the market fitting API 610 standard seal chambers.
Technical Data
Temperature From -70 up to +425°C 
Dynamic Pressure Up to 50 bar (with reinforced metal bellows) 
Static Pressure Up to 90 bar
Linear Speed Up to 50 m/sec (with standard metal bellows) 

See also: 

  • APITERM SD - The new generation, very compact, stationary welded metal bellows mechanical seal, for high temperature applications
  • SO - Single cartridge welded metal bellows mechanical seal, for high temperature applications 
  • APILITE RDT - Tandem o-ring mechanical seal for oil refineries and petrochemical plants which shares many components and technologies from the APILITE SDN bellows seal
  • SDVT - Tandem cartridge welded metal bellows mechanical seal with stationary o-rings, for chemical applications 
  • RO - Single cartridge o-ring mechanical seal

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