SIZING TALL STACKS

Sizing tall stacks will require you to use different sizing tables. A tall stack is one that has more than three branch intervals. Figure 4.19 and Figure 4.20 will show you the basics needed to size tall stacks for two different codes. There are differences in the number of fixture units allowed between the two codes. Since the tables are so much like others we have used, I won’t go into a lot of detail on them.

SUPPORTS

SIZING TALL STACKS

supports for drainage systems are needed. The distance between supports varies with the type of pipe being used and the local code that you are work­ing with. There are also differences between vertical and horizontal piping when you are designing your support placement. We could talk about this, but it would be faster and easier to just give you some reference tables to use when you need them. Figure 4.21 is for horizontal pipe with one code and

FIGURE 4.20 ■ Stack-sizing tall stacks in Zone Three (stacks with more than three branch intervals). (Courtesy of McGraw-Hill)

Maximum distance of supports (ft)

 

ABS

4

Cast iron

At

Galvanized (1 in and larger)

12

Galvanized (% in and smaller)

10

PVC

4

Copper (2 in and larger)

10

Copper (lVfc in and smaller)

6

Support material

Подпись: *Cast-iron pipe must be supported at each joint, but supports may not be more than 10 ft apart.

FIGURE 4.21 ■ Horizontal pipe-support intervals in Zone One. (Courtesy of McGraw-Hill)

Подпись: ✓ fast code fact Horizontal drainage pipe is required, normally, to be supported at a maximum interval of four feet.

Подпись: Maximum distance of supports (ft)

Figure 4.22 is for the same situation, but with a different code. Figure 4.23 deals with vertical pipes for one code, and Figure 4.24 shows vertical support requirements for a different code.

Type of drainage pipe

ABS

4

Cast iron

At

Galvanized (1 in and larger)

12

PVC

4

Copper (2 in and larger)

10

Copper (IV2 and smaller)

6

FIGURE 4.22 ■ Horizontal pipe-support intervals in Zone Two. (Courtesy of McGraw-Hill)

Type of drainage pipe Maximum distance of supports*

 

4 ft

At each story

At least every other story

At each storyt

Not mentioned

Not mentioned

 

Lead pipe

Cast iron

Galvanized

Copper

PVC

ABS

 

*A11 stacks must be supported at their bases. tSupport intervals may not exceed 10 ft.

 

Type of drainage pipe Maximum distance of supports (ft)*

 

Lead pipe Cast iron Galvanized

Copper (lVi in and smaller) Copper (IV2 and larger) PVC (ІУ2 in and smaller) PVC (2 in and larger)

ABS (ІУ2 in and smaller) ABS (2 in and larger)

 

4

At each storyt At each storyt 4

At each story 4

At each story 4

At each story

 

*A11 stacks must be supported at their bases. tSupport intervals may not exceed 15 ft. ^Support intervals may not exceed 30 ft.

 

FIGURE 4.24 ■ Vertical pipe-support intervals in Zone Two. [Courtesy of McGraw-Hill)

Updated: 14 ноября, 2015 — 6:19 пп