ORTAL Clear 200, Инструкция по установке и эксплуатации, Страница: 71 / 156

71
Working with Vertical Elbows
When doing an installation involving vertical elbows, keep the following guidelines in mind:
x
Only two 90-degree elbows are allowed per installation. An installation involving more than two 90-
degree elbows requires manufacturer’s approval.
x
Each 90-degree bend can be calculated as 2 x 45-degree bends. For example, an installation can have
two 45-degree bends and one 90-degree bend, OR four 45-degree bends and no 90-degree bends.
SCENARIO A
When you have vertical elbows of 45 degrees, no additional length for the (H) calculation for the restrictor plate
size is needed. For example:
Total height of duct work = 180cm (V)
Length between the center of the two 45-degree elbows = (B) = 90cm
The (H) calculation is (H) = (B) so the restrictor plate size is 50mm, per the table.
SCENARIO B
If there are two 90-degree elbows in the flue system, an additional 180cm must be added to the (H) calculation
for the restrictor plate size. For example:
Total height of duct work = 540cm (V)
Length between the center of two 90-degree elbows = (B) = 63cm
The (H) calculation to be used in the restrictor table is (H) = (B) +180cm, so the (H) length is 510cm.
Per the table, the restrictor plate is 0. No restrictor is required.