B400 Series Emergency Relief Manway Specification
The B400 Series ensures that tanks and vessels are kept safe during periods of excessive pressure due to external fire sources and also allows access to the tank for inspection / cleaning purposes.
- Standard Pressure settings + 4 mbarg to 140 mbarg
- Size range 6" ( 150 mm ) – 36" ( 900 mm )
- Standard body materials – Aluminium, Carbon steel, Stainless steel
- Diaphragm material - PTFE
- Machineable seats
- Standard drilled flanges – ANSI / DIN / API
- Automatic re seat
- Non standard applications – Consult factory

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.


