If the fabrication shop doesn’t have an automatic Pittsburgh seam machine then there are hand held models or it can be hammered over by a shop worker the old fashion way. To lock the two ends of the Pittsburgh seam together it is run through a Pittsburgh Lock machine that folds over the standing lip, effectively locking the two pieces together. The Pittsburgh seam comes in small and large sizes depending on the pressure requirements of the ductwork.
The Pittsburgh seam is used for pressure classes and duct sizes larger than the Snap Lock seam can handle. Standing Seam Pittsburgh Seams Pittsburgh Seam Depending on the size of the duct, the standing seam will extend upward either by 1 inch or 1-1/2 inches. The use of a standing seam provides strengthening for the larger ducts. When ducts get too wide they could require an additional seam to add strength and span the greater distances. Snap Lock and the Pittsburgh seam are the most typical seams used or specified in the HVAC commercial construction industry that we have witnessed. Really large ducts and fittings can have more than 4 seams as required to provide strength and span wide areas, but in most cases there will be 1 or 2 seams. The seam is highlighted in the below image.Įach section of duct can have 1 to 4 seams depending on how large the duct is. The seams hold together the duct or section of a single fitting as opposed to a joint that connects two separate pieces together. Seams run parallel to the air flow, while joints are perpendicular to the air flow. Seams run longitudinal along the length of the duct run, while joints run transverse (across).
0 kommentar(er)
