Non-Sparking thief hatch

[nsbreddy]

may be a silly question, but wanna know it right!

Can someone through some light on when to use non-sparking thief hatch and when to use self-closing thief hatches.

 

[Duwe6]

Always buy non-sparking; they are the'generic' cast aluminum semi-indestructable hatches. As for self-closing, that is a 'comfort & ease-of-operation' issue. You will have to get a response from the Engineer over the tank farm. Self-close don't seal well, if at all, but every Operator will want them. Up to the Engineer as to how much vapor leakage he can live with.

For LDAR chemicals in the USA, the allowable rate is so low that latching hatches w/gaskets are mandatory. In my tanks that are in flammable-liquid service -- flash point below 100°F -- all thief/sample/gauging hatches are latching. My current favorite is the Shand & Jurs 95021 woth 'Quick-Clamp' option. Works great, keeps the vapor leakage in the part-per-millions range.

 

[nsbreddy]

Thanks Duwe6,
Useful info.