Crosby J Series Direct Pressure Relief Valves

Crosby J Series Direct Pressure Relief Valves

Crosby™ J-Series valves provide high quality and dependable overpressure protection for air, gas, steam, vapor, liquid and two-phase applications in one simple design.

Sapag 8000 series will be discontinued in September 2024. It will be replaced by Crosby J series.

Read more about the option with the balanced-diaphragm safety valve JDS-E here.

Any questions?

Joachim Nyqvist
Solution Seller
Phone. +46 54-57 92 17

Kenneth Olsson
Account Manager
Phone. +46 54-57 92 04

Anders Praem
Inside Sales Engineer
Phone. +45 2137 7759

Frank Kirk Hansen
Area Account Manager West
Phone. +45 4053 6511

Slawka Pedersen
Inside Sales Manager
Phone. +45 2137 7702

Henna Ketoja
Inside Sales Engineer
Mob. +358 400 612 124

Jani Collan
Key Account Manager
Mob. +358 40 702 8711

Tommi Penttilä
Sales Manager Conventional Power
Phone. +358 207 416 208

  • ASME/NB certified capacities for air, water and steam.
  • Full compliance with all major global pressure relief standards including ASME VIII, XIII, API 526/527, EN4126 and PED/CE.
  • Highly customizable to meet most applications.
  • Interchangeable parts to reduce maintenance costs.
  • Full nozzle configuration.
  • Simple and reliable design for easy maintenance.
  • Soft seat options for superior seat tightness.
  • Adjustable blowdown to reduce product loss.
  • Restricted Lift available.
  • Wired or Wireless Relief Monitoring available.


  • Crosby™ Balanced Diaphragm
    • 20% greater backpressure handling improves reliability during backpressure surges.
    • 15% improvement in Kb factor enables sizing of smaller and/or fewer valves.
    • 100x more resilient than metal bellows for high-frequency cycling, ensuring safety.
    • Easily convert existing Crosby J-Series with Balanced Diaphragm upgrade kits.
  • Crosby™ Bellows Leak Detection available
    • Instant notification of bellows rupture allows effective maintenance protocol.
    • Detection of small ruptures, from 0.0009in2 (D orifice).
    • Ensured balanced operation after bellows rupture enhances safety.
    • Leakage volumetric calculation in real-time for risk assessment and decision making.
    • Over 90% reduction of leakage through bonnet vent.
    • Easily enhance existing Crosby J-Series with Bellows Leak Detection upgrade kits.

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