18" x 12" to 8" Round Square-to-Round Transition, 12" Long — $81.24
- Rectangular: 18" x 12"
- Round: 8" dia
- Length: 12"
- Gauge: 22 ga
- Material: Galvanized Steel
- Connections: Slip & drive
- Fabrication: Made to order in Pittsburgh, PA
- Lead time: Ships in 1 business day
- Returns: Made to order, not returnable
Custom fabricated square-to-round transition, 18" x 12" rectangular inlet to 8" round outlet, 12" long, 22-gauge galvanized steel. Gored and riveted, made to order in Pittsburgh.
18" x 12" to 8" Round Square-to-Round Transition, 12" Long: sizing numbers
Worked out from this size's dimensions, so you can check it against your duct design before you order.
| Rectangular inlet free area | 1.50 sq ft (18" x 12") |
| Round outlet free area | 0.35 sq ft (8" diameter) |
| Outlet area as a share of inlet | 23% |
| Velocity change, inlet to outlet | x 4.30 |
| Round duct with the same area as the inlet | 16.6" diameter |
| Body length | 12" |
Airflow by velocity
| Air velocity | Rectangular inlet (1.50 sq ft) | Round outlet (0.35 sq ft) |
|---|---|---|
| 600 fpm | 900 CFM | 210 CFM |
| 700 fpm | 1,050 CFM | 245 CFM |
| 900 fpm | 1,350 CFM | 315 CFM |
| 1,200 fpm | 1,800 CFM | 420 CFM |
Airflow is free area times air velocity. Pick the row that matches the velocity your design uses; these figures are capacity at that velocity, not a pressure-loss calculation.
Questions about this size
Is an 8" round outlet the right size for an 18" x 12" duct?
The round duct with the same free area as 18" x 12" is 16.6" in diameter. This fitting's 8" outlet has 23% of the inlet's area (0.35 sq ft against 1.50 sq ft), which is smaller than the inlet, so the air speeds up about 4.30 times. Choose the outlet that matches the round run or equipment collar you are connecting to.
How many CFM does an 18" x 12" to 8" round transition carry?
At 900 fpm in the 8" round outlet it carries about 315 CFM, which moves through the 18" x 12" inlet at about 210 fpm. At 700 fpm in the outlet it carries about 245 CFM.
What gauge is an 18" x 12" to 8" round transition made in?
22-gauge galvanized steel. PMX picks the gauge from the distance around the largest opening: the 18" x 12" inlet is 60" around, and openings that measure over 54" up to 84" around are built in 22 gauge. The configurator on this page lets you choose 26, 24, 22 or 20 gauge and re-prices it.
How much does an 18" x 12" to 8" round transition cost?
$81.24 as configured on this page: 22-gauge galvanized steel, made to order. The price comes from the same quoting engine that prices the cart, and changing any dimension in the configurator re-prices it. The same size is $129.99 in aluminum and $178.74 in stainless steel. In galvanized steel, the 18" long version is $88.71.
Can I order a square-to-round transition in a different size?
Yes. This page is one published size; the configurator above is loaded with these dimensions and every one of them can be changed to the size you measured, in galvanized steel, aluminum or stainless steel. Each fitting is cut and formed for the order in Pittsburgh, PA.
How fast does an 18" x 12" to 8" round transition ship, and can it be returned?
It ships in 1 business day from our Pittsburgh, PA shop, by UPS or by LTL freight for large orders, anywhere in the continental US. Shipping is calculated at checkout from the order's weight and destination. Because it is made to the dimensions you order, it is not returnable.
About this size
This page is the 18" x 12" to 8" Round Square-to-Round Transition, 12" Long configuration of our square-to-round transition. It is cut and formed for this order — nothing here is a stock import part. The configurator above is loaded with these exact dimensions, so you can add it to the cart as-is, or change a dimension and it re-prices instantly.