“With over 40 years experience in the Low Pressure tank market, we are perfectly placed to offer products designed and engineered to last.”

  • Quality Assurance to ISO9001:2008
  • PED 97/23/EC
  • ATEX Directive 94/9/EC

B550 FV Free Vent - Specification

The B550 Series ensures that tanks and vessels are kept safe by free venting during storage, filling and emptying.

  • Size range 2" ( 50 mm ) – 12" ( 300 mm )
  • Standard body materials – Aluminium, Carbon,Stainless steel
  • Standard trim material – Stainless steel
  • Standard full form flanges – ANSI / DIN
  • Lightweight design
  • Non standard applications – Consult factory


Low cost maintenance - Lightweight design provides easy handling whilst interchangeable components ensure standard parts are easily replaced.

Testing / Quality - All products are factory tested and fully certified.

Self Draining - All products are designed to ensure that condensate drains away from all seating areas.

Low leakage - Standard seating design ensures minimum leakage of less than 1 scfh at 90% of set pressure.

Internal Parts - Internal parts are stainless steel as standard. Non standard materials available upon request.

Connections - All valves are supplied with full form flanges to meet individual requirements. Other connections are available upon request.

Non Standard Applications - There are numerous options available for special applications. Exotic materials such as Hastelloy, Monel and various plastics can be offered to suit the most hazardous of environments. Special coatings can also be applied for extreme service. For low temperature duties, internal parts can be PTFE coated to prevent seizure.

  • 3B Controls Ltd manufacture a comprehensive range of safety relief valves.
  • Our goal is to meet your requirements !
  • We aim to produce low pressure safety relief valves that exceed the industry standard and to deliver them in less than four weeks.

3B Controls Ltd has achieved accreditation to the following: Quality Assurance to ISO 9001:2000 • PED 97\23\EC • ATEX Directive 94\9\EC

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We have finalised our Corporate Presentaion and compiled it with a PDF catologue. Please email us to request the CD to be posted to you.