Flush type opening in API 650 Tank 1

[nabeel3]

Dear All
Is it Mandatory to provide a Flush type shell Man way opening or a flush type clean out fitting in a API 650 tank? Also, what is the purpose of thermal stress relief in such a connection (Section 5.7.4)

 

[IFRs]

It is not required but if the purchaser wants one it shall be done in accordance with API 650 including the thermal stress relief which does exactly as it says - heating and cooling the assembly to appropriate temperature and durations to remove residual stressed from welding.

 

[Dhurjati Sen]

Clean out doors plates are generally thicker than the shell plates. Purpose of stress relief is to remove all stress generated during wedding.

 

[LittleInch]

Mandatory implies legislation / government requirement, so no it isn't.

It might be a good idea or not depending on how often you think you need to clean the tank out of a lot of material.

"all stress generated during wedding." Oh yes there's a lot of stress in a wedding.....

 

[JStephen]

API gives details for round shell manways, flush manways, and roof manways, but doesn't actually specify a minimum number or size for any of them.
A flush manway allows better access for cleaning, but some tanks don't require much cleaning, either.

 

[HTURKAK]

When somebody says ' flush ' i would understand the surfaces coincide and in this case , manway bottom and tank inside bottom coincide. IFAIK, the use of flush-type cleanout is not normative but could be specified by the Purchaser/ end user if flush cleaning is necessary.
I checked my documents and see thta some clients specify flush-type cleanout for crude oil tanks and chemical tanks.
I found the following pdf drawing for combination cleanout and water draw -off detail.

Library Drawings Dc 950012 001-Api Asme Resources – 1 File Download

1filedownload.com

 

[nabeel3]

Thank you for the reply

 

[r6155]

The length of the manway neck must be as minimum as possible to facilitate the access and egress.
Flush type is the best.