Retrofitting of a duct designed for a lower pressure class

[Pritam92]

Dear experts,
We have an issue of duct opening at multiple places along the longitudinal and transverse joints in our site. After a preliminary study it was observed that the duct has been designed for a lower pressure class 3''WG where as required pressure is 10''WG. H-18t was used following the SMACNA standard for 3''WG pressure with duct dimension above 97''. We want this system needs to be retrofitted for higher pressure class of 10''WG.

SMACNA recommends a minimum gauge thickness of 16g for 10'' WG pressure. Is there any way to qualify the existing 18 gauge duct to higher pressure class of 10''WG (With some additional stiffeners). If not so, kindly give suggestions incorporating minimum changes in site.

Any kind of recommendation is greatly appreciated.

 

[EnergyProfessional]

You already mentioned stiffeners. Look at SMACNA book for a 18 gage duct for 10" and add stiffeners to be like that.

 

[Pritam92]

Thank you for your response,
SMACNA recommends only H-16t for the duct dimension above 97'' and 10''WG.