Weil-McLain 550-141-826/1201 manual Appendix, Combustible Surface A 6 Protection

Appendix

CONTINUED

Combustible Surface

A

6" 6"

Protection

Type “L” Doublewall

Vent Piping

Flue Pipe Clearances

FIGURE 19

PROTECTION REQUIRED FOR CLEARANCES LESS THAN 6 INCHES FROM DOUBLEWALL VENT PIPE*

DIMENSION A
When desired minimum
clearance from type “L”
doublewall vent pipe to	Use the following
combustible surface is:	protection**:
	½" thick insulation board ***
3"	over one-inch glass fiber or
	mineral wool batts+
	24 gauge sheet metal with
2"	one-inch ventilated air space
	½" thick insulation board ***
3"	with one-inch ventilated air space

*All clearances measured from outer surface of equipment to combustible surface, not to the protection used.

**Apply to combustible surface unless otherwise noted. Cover all surfaces as specified in Table and FIGURE 19. Thicknesses are minimum.

***Factory-fabricated board made of non-combustible materials, normally fibers, having thermal conductivity in range of one (Btu-inch)/(hr./sq. ft./°F) or less.

+Mineral wool batts (blanket or board), having min. density of 8 lb/ft3 and a min. melting point of 1500°F.

OTHER DIMENSIONS AVAILABLE. REFER TO NFPA-31.

A

A

24" For Servicing

or Min. 2" for Close

Clearances

A

Combustible

24" For Servicing

Surface

or Min. 2" for Close

A

Clearances

Combustible

Surface

2"

Combustible

Surface

Combustible

2"

Surface

2"

NOTE: 2" Min. on Sides

NOTE: 2" Min. on Sides

Back Vent Clearances

Top Vent Clearances

FIGURE 20

FIGURE 21

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