API653 - Low Nozzle Problems.
API653 - Low Nozzle Problems.
(OP)
I have a tank which has a very low nozzle which I have been asked to inspect to API653. It has never been inspected before, and the drawings have some references to API650.
This is a 6" nozzle, which has been installed touching the floor to shell joint. The strake is 17mm thick, and the nozzle has been installed with a 25mm doubler plate.
I have told the client that the nozzle doen't comply (tank built in 1980) and probably never did. I have told them that the nozzle needs to be cut out (if not required) or replaced with an insert plate, and a nozzle to the API650 height.
My 1st question is - have I told them the correct thing? Should this really be cut out? (Also bear in mind that New Zealand is a seismic zone)
Then I had to inspect another tank (unknown code too) which has a manhole almost identical - touching the floor-to-shell weld. They have asked if the 6" nozzle doesn't comply and has to be replaced - what happens with the manway on the other tank??
Can anyone offer me some advice??
This is a 6" nozzle, which has been installed touching the floor to shell joint. The strake is 17mm thick, and the nozzle has been installed with a 25mm doubler plate.
I have told the client that the nozzle doen't comply (tank built in 1980) and probably never did. I have told them that the nozzle needs to be cut out (if not required) or replaced with an insert plate, and a nozzle to the API650 height.
My 1st question is - have I told them the correct thing? Should this really be cut out? (Also bear in mind that New Zealand is a seismic zone)
Then I had to inspect another tank (unknown code too) which has a manhole almost identical - touching the floor-to-shell weld. They have asked if the 6" nozzle doesn't comply and has to be replaced - what happens with the manway on the other tank??
Can anyone offer me some advice??





RE: API653 - Low Nozzle Problems.
Just like in Oz, the Kiwis can use the flush nozzles, which are allowed bu our big brother, as per the API 650. Obviously, you have to be the judge of work done properly, but by the sound of it, it seems OK.
cheers mate,
gr2vessels
RE: API653 - Low Nozzle Problems.
RE: API653 - Low Nozzle Problems.
In your case, the 6" might be ok left as it is but a proper evaluation would take into consideration diameter, thickness, corrosion, risk of failure, etc. I would be far less inclinded to leave a manway in like that.
RE: API653 - Low Nozzle Problems.
In the tank with the low manway, the tank is only 8.5m diameter, x 6m high, with low stresses - so I'm less worried about this one.
RE: API653 - Low Nozzle Problems.
You may want to do the same thing, the geometry is usually pretty simple.
RE: API653 - Low Nozzle Problems.
1. It has been in service for a long time in this configuration. (i.e. if it works, don't fix it) and 2. there was little or no corrosion.
But if there are other repairs to be done on the tank, I'd go ahead and fix it since the crew will already be on site.
RE: API653 - Low Nozzle Problems.
We are removing the low nozzle altogether. We have a door sheet and 2 strake plates also to be replaced..
Cheers
RE: API653 - Low Nozzle Problems.
Joe Tank