API 620 fiberglass question

[jtk921]

I have a large silo constructed to the API 620 standard which is rated for 3.6 psig MAWP at 176 F. The top of the silo is 100 ft. up and we have a very heavy 20" 150# manway cover on top that we would like to replace with a fiberglass manway cover to make access easier and also because we would like to mount a new conservation vent on it. Is this allowed under API 620 as long as the thickness is adequate?

 

[JStephen]

API-620 just addresses steel construction.

 

[KernOily]

Can you install a davit over the existing steel manway cover to help move it around up there?

That's what we do on big honking doghouse cleanout doors on large API 650 tanks: install a davit over the door/manway cover. Then all the crew has to do is bust off all the stud bolts and nuts and use the davit to swing the door out of the way. Two-man job w/hand tools and no crane required. Thanks! Pete