What is a Pittsburgh lock seam?

The Pittsburgh Lock is the most common longitudinal seam in Rectangular Duct. It is comprised of two parts: the Pittsburgh seam (which is basically a pocket and an extending straight flange) and the 90 degree Right Angle Flange.

Similarly, what is a Pittsburgh joint?

The Look of a Pittsburgh Seam Basically, the seam shown below on the left is a Pittsburgh seam and gets it's name from the machine that forms it. A sheet metal plenum with a Pittsburgh joint needs a quarter inch bend on the opposite side that will sit inside the Pittsburgh joint.

Also, what is a Lockformer used for? Lock former/Pittsburgh machine/Pittsburgh rollformer, mainly used for nipping the plate to facilitate the joint of plate, is among the most basic equipments for modern duct forming line. All gears, axles and rollers equipped in the machine are made from high quality steel to ensure their stability and durability.

Consequently, how do you make a Pittsburgh seam?

How to Make a Pittsburgh Joint in Sheet Metal by Hand

Open the jaws of a sheet metal hand brake by pushing the top handle away from the brake's jaws.
Slide a piece of sheet metal into the opening in the brake jaws.
Pull the bent sheet metal out from the open brake jaws.
Lift the lower die handle until the metal sits tight to the angled top brake blade.

How do you bend ducts for drive cleats?

S-cleats are used to connect two lengths of duct together. Connect the second length of duct to the first by sliding its upper and lower ends into the S-cleats. Align the Drive Cleat so that its ends extend beyond the duct. Using a hammer, bend its ends so that they lay flat against the duct.

How do you make a sheet metal duct?

How to Make HVAC Ducts

Place a 4 foot by 8 foot piece of sheet metal on the work table.
Lay the steel ruler on the metal parallel to the edge of the long side.
Align the end of the ruler with the edge of the metal.
Slide the ruler away from the end of the metal until the end of the ruler lines up with one of the 1 inch marks.

How do you speed up ductwork?

There are better and more effective ways to attach HVAC ducts that will seal and be a permanent solution.

Push the ducts together firmly.
Insert 1/2-inch self-tapping sheet metal screws through metal ducts where the ends come together.
Staple fiberglass ducts together with a staple gun and 1/2-inch staples.

How do you insulate round ducts?

If your round air ducts run below the joists, lay one insulation batt on top of the duct. Direct your helper to hold a second batt up to the underside of the duct. Wrap the twine snugly around the duct to hold the top and bottom insulation batts in place.

How far can I run flex duct?

1. Flexible duct shall be supported at manufacturer's recommended intervals, but at no greater distance than four feet. Maximum permissible sag is 1/2 inch per foot of spacing between supports. A connection to rigid ducting or equipment shall be considered a support joint.