External Floating Roof Tank safety devices
External Floating Roof Tank safety devices
(OP)
Hi,
Is it recommendable to install a pressure-vacuum valve on an external floating roof tank? We have a gasoline service tank and we need to know about if is neccesary to install that PV valve.
Regards
Is it recommendable to install a pressure-vacuum valve on an external floating roof tank? We have a gasoline service tank and we need to know about if is neccesary to install that PV valve.
Regards





RE: External Floating Roof Tank safety devices
RE: External Floating Roof Tank safety devices
The case I was considering for that tank is the possibility of the roof clogging when product is pumped into or out of the tank.
The API 2000 recommend PV valves on atmospheric tanks with petroleum products with flash point below 37.8ªC (100ªF). This standard doesn't specify safety devices according with the type of roof.
Bestr Regards
RE: External Floating Roof Tank safety devices
Point C.3.9 VENTS of Appendix C on Welded Steel Tanks for Oil Storage API STANDARD 650 states:
“Suitable vents shall be provided to prevent overstressing of the roof deck or seal membrane. The purchaser should specify liquid withdrawal rates so that the fabricator may size the vacuum vents.
Vents, bleeder valves, or other suitable means shall be adequate to evacuate air and gases from underneath the roof during initial filling”.
Maybe this answers your question
Regards
Luis Marques
RE: External Floating Roof Tank safety devices
You're right the API 650 section that you've mentioned I think it means to put vents under the floating roof.
What about the NFPA 30 ? In point 4.2.5.2.2 says: "For vertical tanks, the emergency relief venting construction shall be permitted to be a floating roof...."
Regards
RE: External Floating Roof Tank safety devices
RE: External Floating Roof Tank safety devices
Best Regards
RE: External Floating Roof Tank safety devices