NCC 2022 Volume One - Building Code of Australia Class 2 to 9 buildings

30

Specification 30 Installation of boilers and pressure vessels

Specification 30 Installation of boilers and pressure vessels

Specification 30 only applies to the Deemed-to-Satisfy Provisions.

This Specification sets out the requirements for the installation of boilers and pressure vessels in buildings.

To clarify that Specification 30 includes the requirements for the installation of boilers and pressure vessels.

The distance between the vent of any explosion relief device for a boiler or pressure vessel and any adjacent wall, roof, ceiling or other solid construction shall be calculated in accordance with Table S30C2.

Table S30C2 Minimum clearances for explosion relief
Clearance from Minimum clearance (metres)
Adjacent wall or ceiling/roof
0.4(V/3)1/3MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaGimaiaac6 cacaaI0aGaaiikaiaadAfacaGGVaGaaG4maiaacMcadaahaaWcbeqa aiaaigdacaGGVaGaaG4maaaaaaa@3E1A@
or 0.4 m, whichever is the greater
Two walls at right angles; or one wall and a ceiling/roof
0.6(V/3)1/3MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaGimaiaac6 cacaaI2aGaaiikaiaadAfacaGGVaGaaG4maiaacMcadaahaaWcbeqa aiaaigdacaGGVaGaaG4maaaaaaa@3E1C@
or 0.6 m, whichever is the greater
Table Notes

VMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOvaaaa@36CF@  
is the internal volume of the boiler or pressure vessel being vented up to the connection of the flue.

To specify the requirements for boilers and pressure vessels.

S30C2 provides requirements for the distance between the vent of any explosion relief device and any adjacent wall, roof, ceiling or other solid construction. Table S30C2 provides the minimum clearance required which is based on the volume of the space being vented. The minimum clearance is determined by a formula which includes the volume of the space being vented. The intention of the explosion relief provisions are that in the event of an explosion the extent of damage is limited.

The minimum clearance determined in the first row is 0.4 m from an adjacent wall or ceiling/roof. 
The minimum clearance determined in the second row is 0.6 m from two walls at right angles, or one wall and a ceiling/roof. This scenario poses a higher risk of damage from overpressure experienced during deflagration, therefore the clearance is increased.

Figure Spec 30

Explosion relief device clearance.

Image
Explosion relief device clearance.

Examples

Examples of compliance with Table S30C2.
V = Volume of space being vented (e.g. furnace to the flue connection)
For this example the volume is 5 m3
x = Clearance from adjacent wall or ceiling/roof
y = Clearance from two walls at right angles; or one wall and a ceiling/roof 

Example 1

x = 0.4(V/3)1/3 
x = 0.4(5/3)1/3 
x = 0.47 m
Therefore the minimum clearance is 0.47 m.

Example 2

y = 0.6(V/3)1/3 
y = 0.6(5/3)1/3 
y = 0.71 m
Therefore the minimum clearance is 0.71 m.

(1) Floor surfaces beneath boilers and pressure vessels shall be water resistant and formed to drain away from supports and structural building elements.

(2) Where a safe tray is provided to trap liquids, it must be manufactured from a material resistant to corrosion from the contents of the boiler or pressure vessel.

 

S30C3 contains two parts. The first is to require the floor surface beneath the boiler or pressure vessel to be water resistant and the floor to be graded away from supports and structural building elements. The second is to ensure that where a safe tray is provided, it must be of a material that is resistant to corrosion from the contents of the boiler.

Building elements surrounding a boiler must be protected from any surface heat by refractory material or effective air spaces so that—

  1. steel elements do not exceed a temperature of more than 300°C; and
  2. concrete elements do not exceed a temperature of more than 200°C; and
  3. timber elements do not exceed a temperature of more than 150°C.

 

For steel, concrete and timber elements, S30C4 requires the protection of these elements to prevent exposure to certain temperatures emitted by a boiler or pressure equipment.