1 reply to this topic

[Soothsayer]

Hi.

 

As part of a project I'm working on, we're replacing an atmospheric vent line of a diesel tank and routing the exhaust to a different location. There is an inline flame arrestor (deflagration type) installed on this vent line. Since the length of the pipe downstream of the arrester is increasing significantly (more than 30 meters from the ignition source), the existing flame arrester might not be suitable to protect the tank as unstable detonations might occur in case of deflagration. Is it essential to replace the existing arrestor with a new one of the detonation type? The risk of ignition source around the exhaust has not been precisely quantified, but it is estimated to be considerably low. The flame arrester has been adequately maintained, and its mechanical integrity is good.

 

ISO 23800 in section 4.4.1.3 (Open Vents) states that,

 

''If open vents are selected to provide venting capacity for tanks that can contain a flammable vapour space as defined in 4.4.1.1, a flame-arresting device should be used''. 

 

API RP 2210 in section 6.3 states that:

 

''Ignition sources such as open flames usually are, and certainly can be, excluded from the vicinity of tank vents. Falling embers, unless actually flaming, are not an ignition source for petroleum vapors. Lightning is a potential ignition source, as demonstrated by the occasional ignition of vent stacks that release vapor continuously. However, such stacks are usually taller and thus a much more attractive target for lightning than a tank vent''.

 

The exhaust would be located at a considerable height, but taller structures and lightning rods are present. Since the risk of a lightning strike (the only potential source of ignition) is considerably low, is it acceptable to keep the existing flame arrestor in place?

 

Thanks.

 

 

[breizh]

Hi,

The only one to answer this question is your local safety bureau , if you are not compliant to won't be able to operate .

 

My view 

Breizh